ViBytes Tools
Menu

Developer Tools

Regular expression tester

Test RegExp patterns, flags and capture groups. Review highlighted matches in a local worker with time and size limits.

Pattern up to 2,000 characters, text up to 100,000 and 500 matches. Worker terminated after one second.

What this tool does

Explore JavaScript expressions without running them on the interface thread. A new worker limits the impact of expensive patterns.

How to use it

  1. Enter a pattern without delimiter slashes and your test text.
  2. Set flags such as g or i.
  3. Process, review indices/groups and cancel or reduce the input if it times out.

Verifiable example

Input
Pattern (a+) with g flag; text baa.
Expected result
Match aa at index 1 with captured group aa.

Limitations to review

  • Pattern 2,000 characters, text 100,000, 500 matches and one second per job.
  • Flags depend on the browser. Indices use UTF-16 units. Does not validate patterns for other regex engines.

Read the full tutorial

Related tools

Browse all guides. Local processing: the page downloads HTTP resources but does not send files or input data to a server for these functions.