ProToolBox

Regex Tester - See Every Match Instantly

Type a JavaScript pattern and sample text-get a big match count, unique hits, and a copyable list. Optional live mode and i / m / s flags. Nothing uploads-no signup, no watermark.

Test regular expressions online

Ship validators, log parsers, and grep-style filters with confidence-iterate in the browser first.

1 Pattern · 2 Text · 3 Flags · 4 Match & copy

Pattern & text

Matches

Try or . Extract from JSON? JSON formatter first.

Runs in this tab only-no server upload, no signup, no watermark.

Add a pattern and sample text-see match count, unique strings, and every hit (JavaScript engine).

What you will see: Total matches, unique substrings, and a copyable list. Next: click Find matches or use Live. Flags i / m / s map to JavaScript RegExp.

Matches appear here

Enter a pattern and text to search, or try a sample above.

Next: Copy matches into tickets or tests. ReDoS and engine differences exist-retest in production for critical paths. Turn off Live on huge strings if the tab slows down. · All tools

  • Works in your browser-runs on your device, not our servers
  • No upload required-your input stays in this tab
  • Free and instant
  • No account needed
  • Private by default-the same ProToolbox promise on every page

What this is for

Regex Tester - See Every Match Instantly helps you format, validate, and encode before paste: works in your browser, no account needed. JSON, YAML, Base64, URLs, escapes-check here first, then ship to PRs, Slack, or configs.

  • Re-validate after every payload edit
  • Copy from the panel-nothing leaves your device until you do
  • Local run for tokens and internal data
  • Green here, then paste into production paths

Security: Fast correctness pass only-secrets still go through your team’s review.

Why use a regex tester

Small pattern mistakes break production filters. A fast, local matcher lets you tune expressions before they touch users or logs.

How it works

  1. Enter a pattern and paste sample text.
  2. Set flags (global is always on; add i, m, s as needed).
  3. Click Find matches or keep Live on.
  4. Read counts and the list-Copy matches or refine the pattern.

FAQ

  • Is this PCRE or Python regex? No-JavaScript only. Lookahead and some features differ from other engines.
  • Why cap matches? Very greedy patterns could freeze the tab; we stop after thousands of hits for safety.
  • Secrets in patterns? Still local-only-avoid pasting credentials on shared machines.

Bookmark this page for every parser tweak: one place to prove a pattern before it ships.

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