diff --git a/library/CHANGELOG.md b/library/CHANGELOG.md
index e95526f71..78e1545fb 100644
--- a/library/CHANGELOG.md
+++ b/library/CHANGELOG.md
@@ -4,6 +4,7 @@ All notable changes to the library will be documented in this file.
 
 ## vX.X.X (Month DD, YYYY)
 
+- Add `normalize` action to normalize strings (issue #691)
 - Add support for async schemas to `entriesFromList` util
 - Add support for numbers and symbols to `entriesFromList` util (issue #492)
 - Add `key` property to `SetPathItem` type to improve DX (issue #693, #694)
diff --git a/library/src/actions/index.ts b/library/src/actions/index.ts
index 02002be20..971764bf3 100644
--- a/library/src/actions/index.ts
+++ b/library/src/actions/index.ts
@@ -47,6 +47,7 @@ export * from './minSize/index.ts';
 export * from './minValue/index.ts';
 export * from './multipleOf/index.ts';
 export * from './nonEmpty/index.ts';
+export * from './normalize/index.ts';
 export * from './notBytes/index.ts';
 export * from './notLength/index.ts';
 export * from './notSize/index.ts';
diff --git a/library/src/actions/normalize/index.ts b/library/src/actions/normalize/index.ts
new file mode 100644
index 000000000..eb7d2a202
--- /dev/null
+++ b/library/src/actions/normalize/index.ts
@@ -0,0 +1 @@
+export * from './normalize.ts';
diff --git a/library/src/actions/normalize/normalize.test-d.ts b/library/src/actions/normalize/normalize.test-d.ts
new file mode 100644
index 000000000..da0521642
--- /dev/null
+++ b/library/src/actions/normalize/normalize.test-d.ts
@@ -0,0 +1,31 @@
+import { describe, expectTypeOf, test } from 'vitest';
+import type { InferInput, InferIssue, InferOutput } from '../../types/index.ts';
+import { normalize, type NormalizeAction } from './normalize.ts';
+
+describe('normalize', () => {
+  describe('should return action object', () => {
+    test('with undefined form', () => {
+      expectTypeOf(normalize()).toEqualTypeOf<NormalizeAction<undefined>>();
+    });
+
+    test('with defined form', () => {
+      expectTypeOf(normalize('NFKC')).toEqualTypeOf<NormalizeAction<'NFKC'>>();
+    });
+  });
+
+  describe('should infer correct types', () => {
+    type Action = NormalizeAction<undefined>;
+
+    test('of input', () => {
+      expectTypeOf<InferInput<Action>>().toEqualTypeOf<string>();
+    });
+
+    test('of output', () => {
+      expectTypeOf<InferOutput<Action>>().toEqualTypeOf<string>();
+    });
+
+    test('of issue', () => {
+      expectTypeOf<InferIssue<Action>>().toEqualTypeOf<never>();
+    });
+  });
+});
diff --git a/library/src/actions/normalize/normalize.test.ts b/library/src/actions/normalize/normalize.test.ts
new file mode 100644
index 000000000..b6f89c927
--- /dev/null
+++ b/library/src/actions/normalize/normalize.test.ts
@@ -0,0 +1,60 @@
+import { describe, expect, test } from 'vitest';
+import { normalize, type NormalizeAction } from './normalize.ts';
+
+describe('normalize', () => {
+  describe('should return action object', () => {
+    const baseAction: Omit<NormalizeAction<never>, 'form'> = {
+      kind: 'transformation',
+      type: 'normalize',
+      reference: normalize,
+      async: false,
+      _run: expect.any(Function),
+    };
+
+    test('with undefined form', () => {
+      expect(normalize()).toStrictEqual({
+        ...baseAction,
+        form: undefined,
+      } satisfies NormalizeAction<undefined>);
+    });
+
+    test('with defined form', () => {
+      expect(normalize('NFKD')).toStrictEqual({
+        ...baseAction,
+        form: 'NFKD',
+      } satisfies NormalizeAction<'NFKD'>);
+    });
+  });
+
+  describe('should normalize string', () => {
+    test('with undefined form', () => {
+      expect(
+        normalize()._run({ typed: true, value: '\u00F1' }, {})
+      ).toStrictEqual({
+        typed: true,
+        value: 'ñ',
+      });
+      expect(
+        normalize()._run({ typed: true, value: '\u006E\u0303' }, {})
+      ).toStrictEqual({
+        typed: true,
+        value: 'ñ',
+      });
+    });
+
+    test('with defined form', () => {
+      expect(
+        normalize('NFKD')._run({ typed: true, value: '\uFB00' }, {})
+      ).toStrictEqual({
+        typed: true,
+        value: 'ff',
+      });
+      expect(
+        normalize('NFKD')._run({ typed: true, value: '\u0066\u0066' }, {})
+      ).toStrictEqual({
+        typed: true,
+        value: 'ff',
+      });
+    });
+  });
+});
diff --git a/library/src/actions/normalize/normalize.ts b/library/src/actions/normalize/normalize.ts
new file mode 100644
index 000000000..e093d7a1f
--- /dev/null
+++ b/library/src/actions/normalize/normalize.ts
@@ -0,0 +1,59 @@
+import type { BaseTransformation } from '../../types/index.ts';
+
+/**
+ * Normalize form type.
+ */
+export type NormalizeForm = 'NFC' | 'NFD' | 'NFKC' | 'NFKD';
+
+/**
+ * Normalize action type.
+ */
+export interface NormalizeAction<TForm extends NormalizeForm | undefined>
+  extends BaseTransformation<string, string, never> {
+  /**
+   * The action type.
+   */
+  readonly type: 'normalize';
+  /**
+   * The action reference.
+   */
+  readonly reference: typeof normalize;
+  /**
+   * The normalization form.
+   */
+  readonly form: TForm;
+}
+
+/**
+ * Creates a normalize transformation action.
+ *
+ * @returns A normalize action.
+ */
+export function normalize(): NormalizeAction<undefined>;
+
+/**
+ * Creates a normalize transformation action.
+ *
+ * @param form The normalization form.
+ *
+ * @returns A normalize action.
+ */
+export function normalize<TForm extends NormalizeForm | undefined>(
+  form: TForm
+): NormalizeAction<TForm>;
+
+export function normalize(
+  form?: NormalizeForm
+): NormalizeAction<NormalizeForm | undefined> {
+  return {
+    kind: 'transformation',
+    type: 'normalize',
+    reference: normalize,
+    async: false,
+    form,
+    _run(dataset) {
+      dataset.value = dataset.value.normalize(this.form);
+      return dataset;
+    },
+  };
+}
diff --git a/website/src/routes/api/(actions)/normalize/index.mdx b/website/src/routes/api/(actions)/normalize/index.mdx
new file mode 100644
index 000000000..fe5a90f50
--- /dev/null
+++ b/website/src/routes/api/(actions)/normalize/index.mdx
@@ -0,0 +1,58 @@
+---
+title: normalize
+description: Creates a normalize transformation action.
+source: /actions/normalize/normalize.ts
+contributors:
+  - fabian-hiller
+---
+
+import { ApiList, Property } from '~/components';
+import { properties } from './properties';
+
+# normalize
+
+Creates a normalize transformation action.
+
+```ts
+const Action = v.normalize<TForm>(form);
+```
+
+## Generics
+
+- `TForm` <Property {...properties.TForm} />
+
+## Parameters
+
+- `form` <Property {...properties.form} />
+
+## Returns
+
+- `Action` <Property {...properties.Action} />
+
+## Examples
+
+The following examples show how `normalize` can be used.
+
+### Normalized string
+
+Schema to normalize a string.
+
+```ts
+const StringSchema = v.pipe(v.string(), v.normalize());
+```
+
+## Related
+
+The following APIs can be combined with `normalize`.
+
+### Schemas
+
+<ApiList items={['any', 'special', 'string', 'unknown']} />
+
+### Methods
+
+<ApiList items={['pipe']} />
+
+### Utils
+
+<ApiList items={['isOfKind', 'isOfType']} />
diff --git a/website/src/routes/api/(actions)/normalize/properties.ts b/website/src/routes/api/(actions)/normalize/properties.ts
new file mode 100644
index 000000000..a237738a4
--- /dev/null
+++ b/website/src/routes/api/(actions)/normalize/properties.ts
@@ -0,0 +1,31 @@
+import type { PropertyProps } from '~/components';
+
+export const properties: Record<string, PropertyProps> = {
+  TForm: {
+    modifier: 'extends',
+    type: {
+      type: 'union',
+      options: [
+        {
+          type: 'custom',
+          name: 'NormalizeForm',
+          href: '../NormalizeForm/',
+        },
+        'undefined',
+      ],
+    },
+  },
+  form: {
+    type: {
+      type: 'custom',
+      name: 'TForm',
+    },
+  },
+  Action: {
+    type: {
+      type: 'custom',
+      name: 'NormalizeAction',
+      href: '../NormalizeAction/',
+    },
+  },
+};
diff --git a/website/src/routes/api/menu.md b/website/src/routes/api/menu.md
index f19b81a85..8cf5dec9b 100644
--- a/website/src/routes/api/menu.md
+++ b/website/src/routes/api/menu.md
@@ -120,6 +120,7 @@
 - [minValue](/api/minValue/)
 - [multipleOf](/api/multipleOf/)
 - [nonEmpty](/api/nonEmpty/)
+- [normalize](/api/normalize/)
 - [notBytes](/api/notBytes/)
 - [notLength](/api/notLength/)
 - [notSize](/api/notSize/)