Regex Performance Tester

Measure repeated RegExp.test timing against one sample while terminating patterns that exceed a selected timeout; this cannot prove a regex safe for every input.

Pattern

Flags

Sample text

Iterations

Hard timeout

Static warning

—Total ms

—ms / operation

—Matching runs

—Iterations

ReadyA timeout can stop this sample probe, but no finite test can prove a regex safe or fast for every possible input.

How to use this Regex Performance Tester

Probe regex execution time in a killable Web Worker with a hard timeout. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.