diff --git a/src/pages/string/extract-substring/extract-substring.service.test.ts b/src/pages/string/extract-substring/extract-substring.service.test.ts
new file mode 100644
index 0000000..ecacc55
--- /dev/null
+++ b/src/pages/string/extract-substring/extract-substring.service.test.ts
@@ -0,0 +1,57 @@
+import { expect, describe, it } from 'vitest';
+import { extractSubstring } from './service';
+
+describe('extractSubstring', () => {
+    it('should extract a substring from single-line input', () => {
+        const input = 'hello world';
+        const result = extractSubstring(input, 1, 4, false, false);
+        expect(result).toBe('hell');
+    });
+
+    it('should extract and reverse a substring from single-line input', () => {
+        const input = 'hello world';
+        const result = extractSubstring(input, 1, 5, false, true);
+        expect(result).toBe('olleh');
+    });
+
+    it('should extract substrings from multi-line input', () => {
+        const input = 'hello\nworld';
+        const result = extractSubstring(input, 1, 5, true, false);
+        expect(result).toBe('hello\nworld');
+    });
+
+    it('should extract and reverse substrings from multi-line input', () => {
+        const input = 'hello\nworld';
+        const result = extractSubstring(input, 1, 4, true, true);
+        expect(result).toBe('lleh\nlrow');
+    });
+
+    it('should handle empty input', () => {
+        const input = '';
+        const result = extractSubstring(input, 1, 5, false, false);
+        expect(result).toBe('');
+    });
+
+    it('should handle start and length out of bounds', () => {
+        const input = 'hello';
+        const result = extractSubstring(input, 10, 5, false, false);
+        expect(result).toBe('');
+    });
+
+    it('should handle negative start and length', () => {
+        expect(() => extractSubstring('hello', -1, 5, false, false)).toThrow("Start index must be greater than zero.");
+        expect(() => extractSubstring('hello', 1, -5, false, false)).toThrow("Length value must be greater than or equal to zero.");
+    });
+
+    it('should handle zero length', () => {
+        const input = 'hello';
+        const result = extractSubstring(input, 1, 0, false, false);
+        expect(result).toBe('');
+    });
+
+    it('should work', () => {
+        const input = 'je me nomme king\n22 est mon chiffre';
+        const result = extractSubstring(input, 12, 7, true, false);
+        expect(result).toBe(' king\nchiffre');
+    });
+});
\ No newline at end of file
diff --git a/src/pages/string/extract-substring/index.tsx b/src/pages/string/extract-substring/index.tsx
new file mode 100644
index 0000000..be249e8
--- /dev/null
+++ b/src/pages/string/extract-substring/index.tsx
@@ -0,0 +1,11 @@
+import { Box } from '@mui/material';
+import React from 'react';
+import * as Yup from 'yup';
+
+const initialValues = {};
+const validationSchema = Yup.object({
+  // splitSeparator: Yup.string().required('The separator is required')
+});
+export default function ExtractSubstring() {
+  return <Box>Lorem ipsum</Box>;
+}
\ No newline at end of file
diff --git a/src/pages/string/extract-substring/meta.ts b/src/pages/string/extract-substring/meta.ts
new file mode 100644
index 0000000..30e8f74
--- /dev/null
+++ b/src/pages/string/extract-substring/meta.ts
@@ -0,0 +1,13 @@
+import { defineTool } from '@tools/defineTool';
+import { lazy } from 'react';
+// import image from '@assets/text.png';
+
+export const tool = defineTool('string', {
+  name: 'Extract substring',
+  path: 'extract-substring',
+  // image,
+  description: '',
+  shortDescription: '',
+  keywords: ['extract', 'substring'],
+  component: lazy(() => import('./index'))
+});
\ No newline at end of file
diff --git a/src/pages/string/extract-substring/service.ts b/src/pages/string/extract-substring/service.ts
new file mode 100644
index 0000000..c06a10f
--- /dev/null
+++ b/src/pages/string/extract-substring/service.ts
@@ -0,0 +1,36 @@
+import { reverseString } from 'utils/string'
+
+export function extractSubstring(
+    input: string,
+    start: number,
+    length: number,
+    multiLine: boolean,
+    reverse: boolean
+): string {
+    if (!input) return '';
+    // edge Cases
+    if (start <= 0) throw new Error("Start index must be greater than zero.");
+    if (length < 0) throw new Error("Length value must be greater than or equal to zero.");
+    if (length === 0) return '';
+
+    let array: string[];
+    let result: string[] = [];
+
+    const extract = (str: string, start: number, length: number): string => {
+        const end = start - 1 + length;
+        if (start - 1 >= str.length) return '';
+        return str.substring(start - 1, Math.min(end, str.length));
+    };
+
+    if (!multiLine) {
+        result.push(extract(input, start, length));
+    }
+    else {
+        array = input.split('\n');
+        for (const word of array) {
+            result.push(extract(word, start, length));
+        }
+    }
+    result = reverse ? result.map(word => reverseString(word)) : result;
+    return result.join('\n');
+}
\ No newline at end of file
diff --git a/src/pages/string/index.ts b/src/pages/string/index.ts
index b588dee..1ea0627 100644
--- a/src/pages/string/index.ts
+++ b/src/pages/string/index.ts
@@ -1,3 +1,4 @@
+import { tool as stringExtractSubstring } from './extract-substring/meta';
 import { tool as stringCreatePalindrome } from './create-palindrome/meta';
 import { tool as stringPalindrome } from './palindrome/meta';
 import { tool as stringToMorse } from './to-morse/meta';