# Trim the file extension from a file name

Remove the text from the last dot onward.

Canonical: https://1loc.dev/string/trim-the-file-extension-from-a-file-name/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function trimExtension(name) { const dot = name.lastIndexOf('.'); return dot > 0 ? name.slice(0, dot) : name; }
```

## Input

```json
"invoice-8812.pdf"
```

## Expected output

```json
"invoice-8812"
```

## Edge case

Input:
```json
".env"
```
Output:
```json
".env"
```

## Limits

- The original turned ".env" into an empty string; a leading dot is kept here.

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/trim-the-file-extension-from-a-file-name.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: Uses the last dot and keeps hidden-file names; the original turned ".env" into an empty string. Original MDX retained as inert source evidence.