diff --git a/src/ImageSharp/Formats/Bmp/BmpImageFormatDetector.cs b/src/ImageSharp/Formats/Bmp/BmpImageFormatDetector.cs
index a10f6b74a9..9917179692 100644
--- a/src/ImageSharp/Formats/Bmp/BmpImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Bmp/BmpImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using System.Buffers.Binary;
 
 namespace SixLabors.ImageSharp.Formats.Bmp;
@@ -14,7 +15,7 @@ public sealed class BmpImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 2;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
     {
         return this.IsSupportedFileFormat(header) ? BmpFormat.Instance : null;
     }
diff --git a/src/ImageSharp/Formats/Gif/GifImageFormatDetector.cs b/src/ImageSharp/Formats/Gif/GifImageFormatDetector.cs
index 3f657610c9..562b146ff1 100644
--- a/src/ImageSharp/Formats/Gif/GifImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Gif/GifImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Gif;
 
 /// <summary>
@@ -12,7 +13,7 @@ public sealed class GifImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 6;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
     {
         return this.IsSupportedFileFormat(header) ? GifFormat.Instance : null;
     }
diff --git a/src/ImageSharp/Formats/IImageFormatDetector.cs b/src/ImageSharp/Formats/IImageFormatDetector.cs
index 17f565d2b2..a93e398b51 100644
--- a/src/ImageSharp/Formats/IImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/IImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats;
 
 /// <summary>
@@ -19,5 +20,5 @@ public interface IImageFormatDetector
     /// </summary>
     /// <param name="header">The <see cref="T:byte[]"/> containing the file header.</param>
     /// <returns>returns the mime type of detected otherwise returns null</returns>
-    IImageFormat DetectFormat(ReadOnlySpan<byte> header);
+    IImageFormat? DetectFormat(ReadOnlySpan<byte> header);
 }
diff --git a/src/ImageSharp/Formats/ImageFormatManager.cs b/src/ImageSharp/Formats/ImageFormatManager.cs
index 9f22c62294..748515bdd8 100644
--- a/src/ImageSharp/Formats/ImageFormatManager.cs
+++ b/src/ImageSharp/Formats/ImageFormatManager.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using System.Collections.Concurrent;
 
 namespace SixLabors.ImageSharp.Formats;
@@ -92,7 +93,7 @@ public void AddImageFormat(IImageFormat format)
     /// </summary>
     /// <param name="extension">The extension to discover</param>
     /// <returns>The <see cref="IImageFormat"/> if found otherwise null</returns>
-    public IImageFormat FindFormatByFileExtension(string extension)
+    public IImageFormat? FindFormatByFileExtension(string extension)
     {
         Guard.NotNullOrWhiteSpace(extension, nameof(extension));
 
@@ -109,7 +110,7 @@ public IImageFormat FindFormatByFileExtension(string extension)
     /// </summary>
     /// <param name="mimeType">The mime-type to discover</param>
     /// <returns>The <see cref="IImageFormat"/> if found; otherwise null</returns>
-    public IImageFormat FindFormatByMimeType(string mimeType)
+    public IImageFormat? FindFormatByMimeType(string mimeType)
         => this.imageFormats.FirstOrDefault(x => x.MimeTypes.Contains(mimeType, StringComparer.OrdinalIgnoreCase));
 
     /// <summary>
@@ -159,11 +160,11 @@ public void AddImageFormatDetector(IImageFormatDetector detector)
     /// </summary>
     /// <param name="format">The format to discover</param>
     /// <returns>The <see cref="IImageDecoder"/> if found otherwise null</returns>
-    public IImageDecoder FindDecoder(IImageFormat format)
+    public IImageDecoder? FindDecoder(IImageFormat format)
     {
         Guard.NotNull(format, nameof(format));
 
-        return this.mimeTypeDecoders.TryGetValue(format, out IImageDecoder decoder)
+        return this.mimeTypeDecoders.TryGetValue(format, out IImageDecoder? decoder)
             ? decoder
             : null;
     }
@@ -173,11 +174,11 @@ public IImageDecoder FindDecoder(IImageFormat format)
     /// </summary>
     /// <param name="format">The format to discover</param>
     /// <returns>The <see cref="IImageEncoder"/> if found otherwise null</returns>
-    public IImageEncoder FindEncoder(IImageFormat format)
+    public IImageEncoder? FindEncoder(IImageFormat format)
     {
         Guard.NotNull(format, nameof(format));
 
-        return this.mimeTypeEncoders.TryGetValue(format, out IImageEncoder encoder)
+        return this.mimeTypeEncoders.TryGetValue(format, out IImageEncoder? encoder)
             ? encoder
             : null;
     }
diff --git a/src/ImageSharp/Formats/Jpeg/JpegImageFormatDetector.cs b/src/ImageSharp/Formats/Jpeg/JpegImageFormatDetector.cs
index f2cc631c53..ad2e011a06 100644
--- a/src/ImageSharp/Formats/Jpeg/JpegImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Jpeg/JpegImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Jpeg;
 
 /// <summary>
@@ -12,7 +13,7 @@ public sealed class JpegImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 11;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
         => this.IsSupportedFileFormat(header) ? JpegFormat.Instance : null;
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
diff --git a/src/ImageSharp/Formats/Pbm/PbmImageFormatDetector.cs b/src/ImageSharp/Formats/Pbm/PbmImageFormatDetector.cs
index c982042e02..b249c7ebb8 100644
--- a/src/ImageSharp/Formats/Pbm/PbmImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Pbm/PbmImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Pbm;
 
 /// <summary>
@@ -16,7 +17,7 @@ public sealed class PbmImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 2;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header) => IsSupportedFileFormat(header) ? PbmFormat.Instance : null;
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header) => IsSupportedFileFormat(header) ? PbmFormat.Instance : null;
 
     private static bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
     {
diff --git a/src/ImageSharp/Formats/Png/PngImageFormatDetector.cs b/src/ImageSharp/Formats/Png/PngImageFormatDetector.cs
index 907898e17f..b3a869d411 100644
--- a/src/ImageSharp/Formats/Png/PngImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Png/PngImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using System.Buffers.Binary;
 
 namespace SixLabors.ImageSharp.Formats.Png;
@@ -14,7 +15,7 @@ public sealed class PngImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 8;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
     {
         return this.IsSupportedFileFormat(header) ? PngFormat.Instance : null;
     }
diff --git a/src/ImageSharp/Formats/Tga/TgaImageFormatDetector.cs b/src/ImageSharp/Formats/Tga/TgaImageFormatDetector.cs
index 23f93a8249..9e8af088a8 100644
--- a/src/ImageSharp/Formats/Tga/TgaImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Tga/TgaImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Tga;
 
 /// <summary>
@@ -12,7 +13,7 @@ public sealed class TgaImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 16;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
     {
         return this.IsSupportedFileFormat(header) ? TgaFormat.Instance : null;
     }
diff --git a/src/ImageSharp/Formats/Tiff/TiffImageFormatDetector.cs b/src/ImageSharp/Formats/Tiff/TiffImageFormatDetector.cs
index 24166f6c0f..fdf2ad383b 100644
--- a/src/ImageSharp/Formats/Tiff/TiffImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Tiff/TiffImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Tiff;
 
 /// <summary>
@@ -12,7 +13,7 @@ public sealed class TiffImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 8;
 
     /// <inheritdoc/>
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
     {
         if (this.IsSupportedFileFormat(header))
         {
diff --git a/src/ImageSharp/Formats/Webp/WebpImageFormatDetector.cs b/src/ImageSharp/Formats/Webp/WebpImageFormatDetector.cs
index 50820fd61c..b8c86a90c6 100644
--- a/src/ImageSharp/Formats/Webp/WebpImageFormatDetector.cs
+++ b/src/ImageSharp/Formats/Webp/WebpImageFormatDetector.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 namespace SixLabors.ImageSharp.Formats.Webp;
 
 /// <summary>
@@ -12,7 +13,7 @@ public sealed class WebpImageFormatDetector : IImageFormatDetector
     public int HeaderSize => 12;
 
     /// <inheritdoc />
-    public IImageFormat DetectFormat(ReadOnlySpan<byte> header)
+    public IImageFormat? DetectFormat(ReadOnlySpan<byte> header)
         => this.IsSupportedFileFormat(header) ? WebpFormat.Instance : null;
 
     private bool IsSupportedFileFormat(ReadOnlySpan<byte> header)
diff --git a/src/ImageSharp/Image.Decode.cs b/src/ImageSharp/Image.Decode.cs
index 6953da1cea..f95d9fd7ad 100644
--- a/src/ImageSharp/Image.Decode.cs
+++ b/src/ImageSharp/Image.Decode.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.Memory;
 using SixLabors.ImageSharp.Metadata;
@@ -44,7 +45,7 @@ internal static Image<TPixel> CreateUninitialized<TPixel>(
     /// <param name="configuration">The general configuration.</param>
     /// <param name="stream">The image stream to read the header from.</param>
     /// <returns>The mime type or null if none found.</returns>
-    private static IImageFormat InternalDetectFormat(Configuration configuration, Stream stream)
+    private static IImageFormat? InternalDetectFormat(Configuration configuration, Stream stream)
     {
         // We take a minimum of the stream length vs the max header size and always check below
         // to ensure that only formats that headers fit within the given buffer length are tested.
@@ -76,12 +77,12 @@ private static IImageFormat InternalDetectFormat(Configuration configuration, St
         // Does the given stream contain enough data to fit in the header for the format
         // and does that data match the format specification?
         // Individual formats should still check since they are public.
-        IImageFormat format = null;
+        IImageFormat? format = null;
         foreach (IImageFormatDetector formatDetector in configuration.ImageFormatsManager.FormatDetectors)
         {
             if (formatDetector.HeaderSize <= headerSize)
             {
-                IImageFormat attemptFormat = formatDetector.DetectFormat(headersBuffer);
+                IImageFormat? attemptFormat = formatDetector.DetectFormat(headersBuffer);
                 if (attemptFormat != null)
                 {
                     format = attemptFormat;
@@ -99,7 +100,7 @@ private static IImageFormat InternalDetectFormat(Configuration configuration, St
     /// <param name="stream">The image stream to read the header from.</param>
     /// <param name="format">The IImageFormat.</param>
     /// <returns>The image format or null if none found.</returns>
-    private static IImageDecoder DiscoverDecoder(DecoderOptions options, Stream stream, out IImageFormat format)
+    private static IImageDecoder? DiscoverDecoder(DecoderOptions options, Stream stream, out IImageFormat? format)
     {
         format = InternalDetectFormat(options.Configuration, stream);
 
@@ -118,10 +119,10 @@ private static IImageDecoder DiscoverDecoder(DecoderOptions options, Stream stre
     /// <returns>
     /// A new <see cref="Image{TPixel}"/>.
     /// </returns>
-    private static (Image<TPixel> Image, IImageFormat Format) Decode<TPixel>(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    private static (Image<TPixel>? Image, IImageFormat? Format) Decode<TPixel>(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        IImageDecoder decoder = DiscoverDecoder(options, stream, out IImageFormat format);
+        IImageDecoder? decoder = DiscoverDecoder(options, stream, out IImageFormat? format);
         if (decoder is null)
         {
             return (null, null);
@@ -131,9 +132,9 @@ private static (Image<TPixel> Image, IImageFormat Format) Decode<TPixel>(Decoder
         return (img, format);
     }
 
-    private static (Image Image, IImageFormat Format) Decode(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    private static (Image? Image, IImageFormat? Format) Decode(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
     {
-        IImageDecoder decoder = DiscoverDecoder(options, stream, out IImageFormat format);
+        IImageDecoder? decoder = DiscoverDecoder(options, stream, out IImageFormat? format);
         if (decoder is null)
         {
             return (null, null);
@@ -152,16 +153,16 @@ private static (Image Image, IImageFormat Format) Decode(DecoderOptions options,
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if a suitable info detector is not found.
     /// </returns>
-    private static (IImageInfo ImageInfo, IImageFormat Format) InternalIdentity(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    private static (IImageInfo? ImageInfo, IImageFormat? Format) InternalIdentity(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
     {
-        IImageDecoder decoder = DiscoverDecoder(options, stream, out IImageFormat format);
+        IImageDecoder? decoder = DiscoverDecoder(options, stream, out IImageFormat? format);
 
         if (decoder is not IImageInfoDetector detector)
         {
             return (null, null);
         }
 
-        IImageInfo info = detector?.Identify(options, stream, cancellationToken);
+        IImageInfo? info = detector.Identify(options, stream, cancellationToken);
         return (info, format);
     }
 }
diff --git a/src/ImageSharp/Image.FromBytes.cs b/src/ImageSharp/Image.FromBytes.cs
index d7d1f26913..0ef6c2854d 100644
--- a/src/ImageSharp/Image.FromBytes.cs
+++ b/src/ImageSharp/Image.FromBytes.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -16,7 +17,7 @@ public abstract partial class Image
     /// </summary>
     /// <param name="data">The byte span containing encoded image data to read the header from.</param>
     /// <returns>The format or null if none found.</returns>
-    public static IImageFormat DetectFormat(ReadOnlySpan<byte> data)
+    public static IImageFormat? DetectFormat(ReadOnlySpan<byte> data)
         => DetectFormat(DecoderOptions.Default, data);
 
     /// <summary>
@@ -26,7 +27,7 @@ public static IImageFormat DetectFormat(ReadOnlySpan<byte> data)
     /// <param name="data">The byte span containing encoded image data to read the header from.</param>
     /// <exception cref="ArgumentNullException">The options are null.</exception>
     /// <returns>The mime type or null if none found.</returns>
-    public static IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byte> data)
+    public static IImageFormat? DetectFormat(DecoderOptions options, ReadOnlySpan<byte> data)
     {
         Guard.NotNull(options, nameof(options.Configuration));
 
@@ -39,7 +40,7 @@ public static IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byt
 
         foreach (IImageFormatDetector detector in configuration.ImageFormatsManager.FormatDetectors)
         {
-            IImageFormat f = detector.DetectFormat(data);
+            IImageFormat? f = detector.DetectFormat(data);
 
             if (f != null)
             {
@@ -59,7 +60,7 @@ public static IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byt
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector not found.
     /// </returns>
-    public static IImageInfo Identify(ReadOnlySpan<byte> data) => Identify(data, out IImageFormat _);
+    public static IImageInfo? Identify(ReadOnlySpan<byte> data) => Identify(data, out IImageFormat? _);
 
     /// <summary>
     /// Reads the raw image information from the specified stream without fully decoding it.
@@ -71,7 +72,7 @@ public static IImageFormat DetectFormat(DecoderOptions options, ReadOnlySpan<byt
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector not found.
     /// </returns>
-    public static IImageInfo Identify(ReadOnlySpan<byte> data, out IImageFormat format)
+    public static IImageInfo? Identify(ReadOnlySpan<byte> data, out IImageFormat? format)
         => Identify(DecoderOptions.Default, data, out format);
 
     /// <summary>
@@ -86,7 +87,7 @@ public static IImageInfo Identify(ReadOnlySpan<byte> data, out IImageFormat form
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector is not found.
     /// </returns>
-    public static unsafe IImageInfo Identify(DecoderOptions options, ReadOnlySpan<byte> data, out IImageFormat format)
+    public static unsafe IImageInfo? Identify(DecoderOptions options, ReadOnlySpan<byte> data, out IImageFormat? format)
     {
         fixed (byte* ptr = data)
         {
@@ -118,7 +119,7 @@ public static Image<TPixel> Load<TPixel>(ReadOnlySpan<byte> data)
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <exception cref="NotSupportedException">Image format is not supported.</exception>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image<TPixel> Load<TPixel>(ReadOnlySpan<byte> data, out IImageFormat format)
+    public static Image<TPixel> Load<TPixel>(ReadOnlySpan<byte> data, out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
         => Load<TPixel>(DecoderOptions.Default, data, out format);
 
@@ -158,7 +159,7 @@ public static unsafe Image<TPixel> Load<TPixel>(DecoderOptions options, ReadOnly
     public static unsafe Image<TPixel> Load<TPixel>(
         DecoderOptions options,
         ReadOnlySpan<byte> data,
-        out IImageFormat format)
+        out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         fixed (byte* ptr = data)
@@ -189,7 +190,7 @@ public static Image Load(ReadOnlySpan<byte> data)
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <exception cref="NotSupportedException">Image format is not supported.</exception>
     /// <returns>The <see cref="Image"/>.</returns>
-    public static Image Load(ReadOnlySpan<byte> data, out IImageFormat format)
+    public static Image Load(ReadOnlySpan<byte> data, out IImageFormat? format)
         => Load(DecoderOptions.Default, data, out format);
 
     /// <summary>
@@ -215,7 +216,7 @@ public static Image Load(DecoderOptions options, ReadOnlySpan<byte> data)
     public static unsafe Image Load(
         DecoderOptions options,
         ReadOnlySpan<byte> data,
-        out IImageFormat format)
+        out IImageFormat? format)
     {
         fixed (byte* ptr = data)
         {
diff --git a/src/ImageSharp/Image.FromFile.cs b/src/ImageSharp/Image.FromFile.cs
index 199d450b89..a2c19361dd 100644
--- a/src/ImageSharp/Image.FromFile.cs
+++ b/src/ImageSharp/Image.FromFile.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using SixLabors.ImageSharp.Formats;
 using SixLabors.ImageSharp.PixelFormats;
 
@@ -16,7 +17,7 @@ public abstract partial class Image
     /// </summary>
     /// <param name="filePath">The image file to open and to read the header from.</param>
     /// <returns>The mime type or null if none found.</returns>
-    public static IImageFormat DetectFormat(string filePath)
+    public static IImageFormat? DetectFormat(string filePath)
         => DetectFormat(DecoderOptions.Default, filePath);
 
     /// <summary>
@@ -26,7 +27,7 @@ public static IImageFormat DetectFormat(string filePath)
     /// <param name="filePath">The image file to open and to read the header from.</param>
     /// <exception cref="ArgumentNullException">The configuration is null.</exception>
     /// <returns>The mime type or null if none found.</returns>
-    public static IImageFormat DetectFormat(DecoderOptions options, string filePath)
+    public static IImageFormat? DetectFormat(DecoderOptions options, string filePath)
     {
         Guard.NotNull(options, nameof(options));
 
@@ -41,7 +42,7 @@ public static IImageFormat DetectFormat(DecoderOptions options, string filePath)
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector not found.
     /// </returns>
-    public static IImageInfo Identify(string filePath)
+    public static IImageInfo? Identify(string filePath)
         => Identify(filePath, out IImageFormat _);
 
     /// <summary>
@@ -52,7 +53,7 @@ public static IImageInfo Identify(string filePath)
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector not found.
     /// </returns>
-    public static IImageInfo Identify(string filePath, out IImageFormat format)
+    public static IImageInfo? Identify(string filePath, out IImageFormat? format)
         => Identify(DecoderOptions.Default, filePath, out format);
 
     /// <summary>
@@ -65,7 +66,7 @@ public static IImageInfo Identify(string filePath, out IImageFormat format)
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if suitable info detector is not found.
     /// </returns>
-    public static IImageInfo Identify(DecoderOptions options, string filePath, out IImageFormat format)
+    public static IImageInfo? Identify(DecoderOptions options, string filePath, out IImageFormat? format)
     {
         Guard.NotNull(options, nameof(options));
         using Stream file = options.Configuration.FileSystem.OpenRead(filePath);
@@ -82,7 +83,7 @@ public static IImageInfo Identify(DecoderOptions options, string filePath, out I
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static Task<IImageInfo> IdentifyAsync(string filePath, CancellationToken cancellationToken = default)
+    public static Task<IImageInfo?> IdentifyAsync(string filePath, CancellationToken cancellationToken = default)
         => IdentifyAsync(DecoderOptions.Default, filePath, cancellationToken);
 
     /// <summary>
@@ -96,12 +97,12 @@ public static Task<IImageInfo> IdentifyAsync(string filePath, CancellationToken
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static async Task<IImageInfo> IdentifyAsync(
+    public static async Task<IImageInfo?> IdentifyAsync(
         DecoderOptions options,
         string filePath,
         CancellationToken cancellationToken = default)
     {
-        (IImageInfo ImageInfo, IImageFormat Format) res =
+        (IImageInfo? ImageInfo, IImageFormat? Format) res =
             await IdentifyWithFormatAsync(options, filePath, cancellationToken).ConfigureAwait(false);
         return res.ImageInfo;
     }
@@ -116,7 +117,7 @@ public static async Task<IImageInfo> IdentifyAsync(
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static Task<(IImageInfo ImageInfo, IImageFormat Format)> IdentifyWithFormatAsync(
+    public static Task<(IImageInfo? ImageInfo, IImageFormat? Format)> IdentifyWithFormatAsync(
         string filePath,
         CancellationToken cancellationToken = default)
         => IdentifyWithFormatAsync(DecoderOptions.Default, filePath, cancellationToken);
@@ -132,7 +133,7 @@ public static async Task<IImageInfo> IdentifyAsync(
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static async Task<(IImageInfo ImageInfo, IImageFormat Format)> IdentifyWithFormatAsync(
+    public static async Task<(IImageInfo? ImageInfo, IImageFormat? Format)> IdentifyWithFormatAsync(
         DecoderOptions options,
         string filePath,
         CancellationToken cancellationToken = default)
@@ -163,7 +164,7 @@ public static Image Load(string path)
     /// Thrown if the stream is not readable nor seekable.
     /// </exception>
     /// <returns>A new <see cref="Image{Rgba32}"/>.</returns>
-    public static Image Load(string path, out IImageFormat format)
+    public static Image Load(string path, out IImageFormat? format)
         => Load(DecoderOptions.Default, path, out format);
 
     /// <summary>
@@ -286,7 +287,7 @@ public static Image<TPixel> Load<TPixel>(string path)
     /// <exception cref="NotSupportedException">Image format is not supported.</exception>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image<TPixel> Load<TPixel>(string path, out IImageFormat format)
+    public static Image<TPixel> Load<TPixel>(string path, out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
         => Load<TPixel>(DecoderOptions.Default, path, out format);
 
@@ -325,7 +326,7 @@ public static Image<TPixel> Load<TPixel>(DecoderOptions options, string path)
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image<TPixel> Load<TPixel>(DecoderOptions options, string path, out IImageFormat format)
+    public static Image<TPixel> Load<TPixel>(DecoderOptions options, string path, out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
     {
         Guard.NotNull(options, nameof(options));
@@ -348,7 +349,7 @@ public static Image<TPixel> Load<TPixel>(DecoderOptions options, string path, ou
     /// <exception cref="NotSupportedException">Image format is not supported.</exception>
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image Load(DecoderOptions options, string path, out IImageFormat format)
+    public static Image Load(DecoderOptions options, string path, out IImageFormat? format)
     {
         Guard.NotNull(options, nameof(options));
         Guard.NotNull(path, nameof(path));
diff --git a/src/ImageSharp/Image.FromStream.cs b/src/ImageSharp/Image.FromStream.cs
index eefb087764..dc94a54241 100644
--- a/src/ImageSharp/Image.FromStream.cs
+++ b/src/ImageSharp/Image.FromStream.cs
@@ -1,6 +1,7 @@
 // Copyright (c) Six Labors.
 // Licensed under the Six Labors Split License.
 
+#nullable enable
 using System.Diagnostics.CodeAnalysis;
 using System.Globalization;
 using System.Text;
@@ -22,7 +23,7 @@ public abstract partial class Image
     /// <exception cref="ArgumentNullException">The stream is null.</exception>
     /// <exception cref="NotSupportedException">The stream is not readable.</exception>
     /// <returns>The format type or null if none found.</returns>
-    public static IImageFormat DetectFormat(Stream stream)
+    public static IImageFormat? DetectFormat(Stream stream)
         => DetectFormat(DecoderOptions.Default, stream);
 
     /// <summary>
@@ -34,7 +35,7 @@ public static IImageFormat DetectFormat(Stream stream)
     /// <exception cref="ArgumentNullException">The stream is null.</exception>
     /// <exception cref="NotSupportedException">The stream is not readable.</exception>
     /// <returns>The format type or null if none found.</returns>
-    public static IImageFormat DetectFormat(DecoderOptions options, Stream stream)
+    public static IImageFormat? DetectFormat(DecoderOptions options, Stream stream)
         => WithSeekableStream(options, stream, s => InternalDetectFormat(options.Configuration, s));
 
     /// <summary>
@@ -45,7 +46,7 @@ public static IImageFormat DetectFormat(DecoderOptions options, Stream stream)
     /// <exception cref="ArgumentNullException">The stream is null.</exception>
     /// <exception cref="NotSupportedException">The stream is not readable.</exception>
     /// <returns>A <see cref="Task{IImageFormat}"/> representing the asynchronous operation or null if none is found.</returns>
-    public static Task<IImageFormat> DetectFormatAsync(Stream stream, CancellationToken cancellationToken = default)
+    public static Task<IImageFormat?> DetectFormatAsync(Stream stream, CancellationToken cancellationToken = default)
         => DetectFormatAsync(DecoderOptions.Default, stream, cancellationToken);
 
     /// <summary>
@@ -58,7 +59,7 @@ public static Task<IImageFormat> DetectFormatAsync(Stream stream, CancellationTo
     /// <exception cref="ArgumentNullException">The stream is null.</exception>
     /// <exception cref="NotSupportedException">The stream is not readable.</exception>
     /// <returns>A <see cref="Task{IImageFormat}"/> representing the asynchronous operation.</returns>
-    public static Task<IImageFormat> DetectFormatAsync(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
+    public static Task<IImageFormat?> DetectFormatAsync(DecoderOptions options, Stream stream, CancellationToken cancellationToken = default)
         => WithSeekableStreamAsync(
             options,
             stream,
@@ -75,7 +76,7 @@ public static Task<IImageFormat> DetectFormatAsync(DecoderOptions options, Strea
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if a suitable info detector is not found.
     /// </returns>
-    public static IImageInfo Identify(Stream stream)
+    public static IImageInfo? Identify(Stream stream)
         => Identify(stream, out IImageFormat _);
 
     /// <summary>
@@ -90,7 +91,7 @@ public static IImageInfo Identify(Stream stream)
     /// A <see cref="Task{IImageInfo}"/> representing the asynchronous operation or null if
     /// a suitable detector is not found.
     /// </returns>
-    public static Task<IImageInfo> IdentifyAsync(Stream stream, CancellationToken cancellationToken = default)
+    public static Task<IImageInfo?> IdentifyAsync(Stream stream, CancellationToken cancellationToken = default)
         => IdentifyAsync(DecoderOptions.Default, stream, cancellationToken);
 
     /// <summary>
@@ -104,7 +105,7 @@ public static Task<IImageInfo> IdentifyAsync(Stream stream, CancellationToken ca
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if a suitable info detector is not found.
     /// </returns>
-    public static IImageInfo Identify(Stream stream, out IImageFormat format)
+    public static IImageInfo? Identify(Stream stream, out IImageFormat? format)
         => Identify(DecoderOptions.Default, stream, out format);
 
     /// <summary>
@@ -119,7 +120,7 @@ public static IImageInfo Identify(Stream stream, out IImageFormat format)
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if a suitable info detector is not found.
     /// </returns>
-    public static IImageInfo Identify(DecoderOptions options, Stream stream)
+    public static IImageInfo? Identify(DecoderOptions options, Stream stream)
         => Identify(options, stream, out _);
 
     /// <summary>
@@ -136,12 +137,12 @@ public static IImageInfo Identify(DecoderOptions options, Stream stream)
     /// A <see cref="Task{IImageInfo}"/> representing the asynchronous operation or null if
     /// a suitable detector is not found.
     /// </returns>
-    public static async Task<IImageInfo> IdentifyAsync(
+    public static async Task<IImageInfo?> IdentifyAsync(
         DecoderOptions options,
         Stream stream,
         CancellationToken cancellationToken = default)
     {
-        (IImageInfo ImageInfo, IImageFormat Format) res = await IdentifyWithFormatAsync(options, stream, cancellationToken).ConfigureAwait(false);
+        (IImageInfo? ImageInfo, IImageFormat? Format) res = await IdentifyWithFormatAsync(options, stream, cancellationToken).ConfigureAwait(false);
         return res.ImageInfo;
     }
 
@@ -158,9 +159,9 @@ public static async Task<IImageInfo> IdentifyAsync(
     /// <returns>
     /// The <see cref="IImageInfo"/> or null if a suitable info detector is not found.
     /// </returns>
-    public static IImageInfo Identify(DecoderOptions options, Stream stream, out IImageFormat format)
+    public static IImageInfo? Identify(DecoderOptions options, Stream stream, out IImageFormat? format)
     {
-        (IImageInfo ImageInfo, IImageFormat Format) data = WithSeekableStream(options, stream, s => InternalIdentity(options, s));
+        (IImageInfo? ImageInfo, IImageFormat? Format) data = WithSeekableStream(options, stream, s => InternalIdentity(options, s));
 
         format = data.Format;
         return data.ImageInfo;
@@ -179,7 +180,7 @@ public static IImageInfo Identify(DecoderOptions options, Stream stream, out IIm
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static Task<(IImageInfo ImageInfo, IImageFormat Format)> IdentifyWithFormatAsync(
+    public static Task<(IImageInfo? ImageInfo, IImageFormat? Format)> IdentifyWithFormatAsync(
         Stream stream,
         CancellationToken cancellationToken = default)
         => IdentifyWithFormatAsync(DecoderOptions.Default, stream, cancellationToken);
@@ -198,7 +199,7 @@ public static IImageInfo Identify(DecoderOptions options, Stream stream, out IIm
     /// The <see cref="Task{ValueTuple}"/> representing the asynchronous operation with the parameter type
     /// <see cref="IImageInfo"/> property set to null if suitable info detector is not found.
     /// </returns>
-    public static Task<(IImageInfo ImageInfo, IImageFormat Format)> IdentifyWithFormatAsync(
+    public static Task<(IImageInfo? ImageInfo, IImageFormat? Format)> IdentifyWithFormatAsync(
         DecoderOptions options,
         Stream stream,
         CancellationToken cancellationToken = default)
@@ -219,7 +220,7 @@ public static IImageInfo Identify(DecoderOptions options, Stream stream, out IIm
     /// <exception cref="UnknownImageFormatException">Image format not recognised.</exception>
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <returns>The <see cref="Image"/>.</returns>
-    public static Image Load(Stream stream, out IImageFormat format)
+    public static Image Load(Stream stream, out IImageFormat? format)
         => Load(DecoderOptions.Default, stream, out format);
 
     /// <summary>
@@ -335,7 +336,7 @@ public static Task<Image<TPixel>> LoadAsync<TPixel>(Stream stream, CancellationT
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image<TPixel> Load<TPixel>(Stream stream, out IImageFormat format)
+    public static Image<TPixel> Load<TPixel>(Stream stream, out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
         => Load<TPixel>(DecoderOptions.Default, stream, out format);
 
@@ -383,10 +384,10 @@ public static Image<TPixel> Load<TPixel>(DecoderOptions options, Stream stream)
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <typeparam name="TPixel">The pixel format.</typeparam>
     /// <returns>A <see cref="Task"/> representing the asynchronous operation.</returns>
-    public static Image<TPixel> Load<TPixel>(DecoderOptions options, Stream stream, out IImageFormat format)
+    public static Image<TPixel> Load<TPixel>(DecoderOptions options, Stream stream, out IImageFormat? format)
         where TPixel : unmanaged, IPixel<TPixel>
     {
-        (Image<TPixel> Image, IImageFormat Format) data = WithSeekableStream(options, stream, s => Decode<TPixel>(options, s));
+        (Image<TPixel>? Image, IImageFormat? Format) data = WithSeekableStream(options, stream, s => Decode<TPixel>(options, s));
 
         format = data.Format;
 
@@ -495,9 +496,9 @@ public static async Task<Image<TPixel>> LoadAsync<TPixel>(
     /// <exception cref="UnknownImageFormatException">Image format not recognised.</exception>
     /// <exception cref="InvalidImageContentException">Image contains invalid content.</exception>
     /// <returns>A new <see cref="Image{TPixel}"/>.</returns>
-    public static Image Load(DecoderOptions options, Stream stream, out IImageFormat format)
+    public static Image Load(DecoderOptions options, Stream stream, out IImageFormat? format)
     {
-        (Image img, IImageFormat fmt) = WithSeekableStream(options, stream, s => Decode(options, s));
+        (Image? img, IImageFormat? fmt) = WithSeekableStream(options, stream, s => Decode(options, s));
 
         format = fmt;