# Check if a path is relative

Return true unless the path starts with a slash or backslash, optionally after a drive or scheme.

Canonical: https://1loc.dev/string/check-if-a-path-is-relative/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function isRelative(path) { return !/^([a-z]+:)?[\\/]/i.test(path); }
```

## Input

```json
"images/logo.png"
```

## Expected output

```json
true
```

## Edge case

Input:
```json
"C:\\Windows\\notepad.exe"
```
Output:
```json
false
```

## Limits

- A scheme without slashes, such as mailto: or data:, still counts as relative. Use the URL-absolute check for URLs.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/check-if-a-path-is-relative.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Curated implementation; explicit input contract, edge case and limits. Original MDX retained as inert source evidence.