https://devtools.solutions/tools/regex/regex-performance-test.html

Run Regex Performance Test

Benchmark a regular expression by running it against a large input string and measuring execution time in milliseconds.

Regex Performance Test


    

Example input/output

Input: Pattern: (a+)+ / Test string: aaaaaaaaaaaaaaaaaab

Output: 1000 iterations in 45ms (avg: 0.045ms per run)

How it works

This tool runs the provided regex against the test string in a loop for the configured number of iterations, using performance.now() to measure elapsed time. Results are shown as total time and average time per iteration. This helps identify catastrophically backtracking patterns (ReDoS). Processing runs in your browser.

Common use cases

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