diff --git a/src/main/java/team/wego/wegobackend/image/application/service/ImageUploadService.java b/src/main/java/team/wego/wegobackend/image/application/service/ImageUploadService.java
index 36e8258..8b0932d 100644
--- a/src/main/java/team/wego/wegobackend/image/application/service/ImageUploadService.java
+++ b/src/main/java/team/wego/wegobackend/image/application/service/ImageUploadService.java
@@ -52,7 +52,8 @@ public ImageFile uploadOriginal(String dir, MultipartFile file, int index) {
         validateExtension(file.getOriginalFilename());
 
         String originalFilename = file.getOriginalFilename();
-        String key = buildKey(dir, originalFilename, index);
+//        String key = buildKey(dir, originalFilename, index);
+        String key = buildKey(originalFilename, index);
 
         byte[] bytes = resizeIfNeededKeepFormat(file);
 
@@ -93,6 +94,29 @@ public ImageFile uploadAsWebpWithSize(
         return new ImageFile(key, url);
     }
 
+
+    // TODO: 회원에서 사용할 단 건 이미지 저장 기능
+    public ImageFile uploadAsWebpWithSize(
+            MultipartFile file,
+            Integer width,
+            Integer height
+    ) {
+        validateImageSize(file);
+        validateImageContentType(file);
+        validateExtension(file.getOriginalFilename());
+        ImageSize size = new ImageSize(width, height);
+
+        String baseName = buildBaseName();
+        String key = baseName + "_" + size.width() + "x" + size.height() + ".webp";
+
+        byte[] bytes = convertToWebpWithSize(file, size);
+
+        putToS3(key, bytes, "image/webp");
+        String url = awsS3Properties.getPublicEndpoint() + "/" + key;
+
+        return new ImageFile(key, url);
+    }
+
     public List<ImageFile> uploadAsWebpWithSizes(
             String dir,
             MultipartFile file,
@@ -128,6 +152,39 @@ public List<ImageFile> uploadAsWebpWithSizes(
         return result;
     }
 
+    public List<ImageFile> uploadAsWebpWithSizes(
+            MultipartFile file,
+            int index,
+            List<Integer> widths,
+            List<Integer> heights
+    ) {
+        if (widths.size() != heights.size()) {
+            // 해당 예외는 이미지 예외 처리로 수행하지 않는다.
+            throw new IllegalArgumentException("widths와 heights의 길이가 일치해야 합니다.");
+        }
+
+        validateImageSize(file);
+        validateImageContentType(file);
+        validateExtension(file.getOriginalFilename());
+
+        String baseName = buildBaseName(index);
+        List<ImageFile> result = new ArrayList<>();
+
+        for (int i = 0; i < widths.size(); i++) {
+            ImageSize size = new ImageSize(widths.get(i), heights.get(i));
+
+            String key = baseName + "_" + size.width() + "x" + size.height() + ".webp";
+            byte[] bytes = convertToWebpWithSize(file, size);
+
+            putToS3(key, bytes, "image/webp");
+            String url = awsS3Properties.getPublicEndpoint() + "/" + key;
+
+            result.add(new ImageFile(key, url));
+        }
+
+        return result;
+    }
+
     public void delete(String key) {
         s3Client.deleteObject(builder -> builder
                 .bucket(awsS3Properties.getBucket())
@@ -197,9 +254,14 @@ private String extractExtension(String originalFilename) {
     }
 
     private void validateDir(String dir) {
-        if (dir == null || dir.isBlank()) {
-            throw new ImageException(ImageExceptionCode.DIR_REQUIRED);
-        }
+        // TODO: 모임 경로: FE 요청으로 루트 디렉토리로 개선했습니다.
+//        if (dir == null || dir.isBlank()) {
+//            throw new ImageException(ImageExceptionCode.DIR_REQUIRED);
+//        }
+
+//        if (!dir.matches("[a-zA-Z0-9_\\-/]+")) {
+//            throw new ImageException(ImageExceptionCode.DIR_INVALID_PATTERN);
+//        }
 
         if (dir.contains("..") || dir.startsWith("/")) {
             throw new ImageException(ImageExceptionCode.DIR_INVALID_TRAVERSAL);
@@ -208,10 +270,6 @@ private void validateDir(String dir) {
         if (dir.endsWith("/")) {
             throw new ImageException(ImageExceptionCode.DIR_TRAILING_SLASH);
         }
-
-        if (!dir.matches("[a-zA-Z0-9_\\-/]+")) {
-            throw new ImageException(ImageExceptionCode.DIR_INVALID_PATTERN);
-        }
     }
 
     private String buildKey(String dir, String originalFilename, int index) {
@@ -223,6 +281,16 @@ private String buildKey(String dir, String originalFilename, int index) {
         return dir + "/" + timestamp + "_" + index + "_" + uuid + extension;
     }
 
+    private String buildKey(String originalFilename, int index) {
+        String extension = extractExtension(originalFilename);
+        String timestamp = LocalDateTime.now()
+                .format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
+        String uuid = UUID.randomUUID().toString();
+
+        return timestamp + "_" + index + "_" + uuid + extension;
+    }
+
+
     private String buildBaseName(int index) {
         String timestamp = LocalDateTime.now()
                 .format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
@@ -230,6 +298,13 @@ private String buildBaseName(int index) {
         return timestamp + "_" + index + "_" + uuid;
     }
 
+    private String buildBaseName() {
+        String timestamp = LocalDateTime.now()
+                .format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
+        String uuid = UUID.randomUUID().toString();
+        return timestamp + "_" + uuid;
+    }
+
     private byte[] resizeIfNeededKeepFormat(MultipartFile file) {
         return resizeToBox(
                 file,
diff --git a/src/main/java/team/wego/wegobackend/image/presentation/ImageController.java b/src/main/java/team/wego/wegobackend/image/presentation/ImageController.java
index 9d36396..33d4d41 100644
--- a/src/main/java/team/wego/wegobackend/image/presentation/ImageController.java
+++ b/src/main/java/team/wego/wegobackend/image/presentation/ImageController.java
@@ -1,6 +1,5 @@
 package team.wego.wegobackend.image.presentation;
 
-import java.util.ArrayList;
 import java.util.List;
 import lombok.RequiredArgsConstructor;
 import org.springframework.http.HttpStatus;
diff --git a/src/test/http/group/create.http b/src/test/http/group/create.http
index 2a423c7..290fa65 100644
--- a/src/test/http/group/create.http
+++ b/src/test/http/group/create.http
@@ -140,22 +140,22 @@ POST http://localhost:8080/api/v1/groups/images/{{groupId}}/upload
     ?userId=1
 Content-Type: multipart/form-data; boundary=boundary
 
---boundary
+--boundary--
 Content-Disposition: form-data; name="images"; filename="test-webp1.webp"
 Content-Type: image/webp
 
 < ../image/resources/test-webp1.webp
---boundary
+--boundary--
 Content-Disposition: form-data; name="images"; filename="test-webp1.webp"
 Content-Type: image/webp
 
 < ../image/resources/test-webp1.webp
---boundary
+--boundary--
 Content-Disposition: form-data; name="images"; filename="img1.png"
 Content-Type: image/png
 
 < ../image/resources/img1.png
---boundary
+--boundary--
 Content-Disposition: form-data; name="images"; filename="img2.jpg"
 Content-Type: image/jpeg