String.prototype.endsWith()

endsWith(searchString, endPosition)

Returns: boolean · Updated March 16, 2026 · String Methods

string endswith searching

The endsWith() method determines whether a string ends with the characters of a specified string, returning true or false as appropriate. It’s the counterpart to startsWith() and provides a cleaner alternative to checking the last N characters of a string.

Syntax

str.endsWith(searchString)
str.endsWith(searchString, endPosition)

Parameters

Parameter	Type	Default	Description
`searchString`	`string`	—	The characters to search for at the end of the string.
`endPosition`	`number`	`str.length`	The end position within the string to search. If omitted, defaults to the string’s length.

Examples

Basic usage

const str = 'Hello, world!';

console.log(str.endsWith('world!'));
// true

console.log(str.endsWith('Hello'));
// false

console.log(str.endsWith('world!', 13));
// true

Case-sensitive matching

const filename = 'document.pdf';

console.log(filename.endsWith('.pdf'));
// true

console.log(filename.endsWith('.PDF'));
// false (case-sensitive)

console.log(filename.endsWith('document'));
// false

Using with file extensions

const files = [
  'image.png',
  'photo.jpg',
  'document.pdf',
  'archive.zip'
];

const images = files.filter(file => file.endsWith('.png') || file.endsWith('.jpg'));
console.log(images);
// ['image.png', 'photo.jpg']

Common Patterns

Validating file types

function isImage(filename) {
  const imageExtensions = ['.jpg', '.jpeg', '.png', '.gif', '.webp'];
  return imageExtensions.some(ext => filename.toLowerCase().endsWith(ext));
}

console.log(isImage('photo.PNG'));
// true

console.log(isImage('document.pdf'));
// false

Checking URL endings

function isSecureUrl(url) {
  return url.endsWith('https');
}

console.log(isSecureUrl('https://example.com'));
// true

console.log(isSecureUrl('http://example.com'));
// false

Use Cases

URL validation

When building web applications, you often need to validate that URLs end with certain patterns. The endsWith() method makes this straightforward:

function hasTrailingSlash(url) {
  return url.endsWith('/');
}

console.log(hasTrailingSlash('https://example.com/page/'));
// true

console.log(hasTrailingSlash('https://example.com/page'));
// false

Extension checking in upload forms

In file upload scenarios, validating the file extension on the client side provides immediate feedback:

function validateUpload(filename, allowedExtensions) {
  return allowedExtensions.some(ext => 
    filename.toLowerCase().endsWith(ext.toLowerCase())
  );
}

const documentExtensions = ['.pdf', '.doc', '.docx'];
console.log(validateUpload('resume.PDF', documentExtensions));
// true

Comparing string endings

Unlike manual comparisons using slice() or substr(), endsWith() is semantic and readable:

const message = 'Hello, JavaScript developer!';

// Using endsWith() - clear intent
console.log(message.endsWith('developer!'));
// true

// Manual approach - harder to read
console.log(message.slice(-10) === 'developer!');
// true (but less clear)

Performance Considerations

The endsWith() method is optimized in modern JavaScript engines. For older environments, a polyfill is available. The method handles Unicode correctly and doesn’t suffer from the edge cases that plague manual length calculations.

Edge Cases

// Empty search string always returns true
console.log('hello'.endsWith(''));
// true

// Position beyond string length uses string length
console.log('hi'.endsWith('hi', 100));
// true

// Case matters
console.log('HELLO'.endsWith('hello'));
// false