File & Path

File Extension

Captures the file extension from a filename.

Try it in RegexPro →

Available in

JSSupported

JavaScript / ECMAScript

Browser-native RegExp. Default if you don't pick.

PYSupported

Python (re)

CPython stdlib `re`. Unicode-aware `\w` and `\d` by default.

GOSupported

Go (RE2)

Linear-time matching. No backreferences or lookarounds.

Pattern

regexengine-agnostic
\.([A-Za-z0-9]+)$

Raw source: \.([A-Za-z0-9]+)$

How it works

`\.` matches the literal dot. `([A-Za-z0-9]+)$` captures alphanumeric characters up to the end of the string.

Examples

Input

document.pdf

Matches

  • .pdf

Input

archive.tar.gz

Matches

  • .gz

Input

no-extension

No match

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Common use cases

  • •File filters
  • •MIME type detection
  • •Upload validation

Related patterns

Image File Extension

File & Path

Match common image file extensions: jpg, jpeg, png, gif, webp, svg, avif, bmp, ico, tif, tiff.

Video File Extension

File & Path

Match common video file extensions: mp4, mov, avi, mkv, webm, m4v, flv, wmv, mpg, mpeg.

Windows File Path

File & Path

Matches absolute Windows file paths (e.g., C:\Users\file.txt).

Unix File Path

File & Path

Matches absolute Unix/Linux file paths.

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