Developer ToolsFree · Testing phase
Regex Tester
Test JavaScript regular expressions with highlighted matches.
Workspace
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Your inputs stay in this page. Only the tool name is sent to record a successful use. No account needed.
Common questions
What limitations apply?
JavaScript flags: g, i, m, s, u. Runs in a disposable worker with a 300ms time limit, 200-character expression limit and 20,000-character text limit. At most 1,000 matches.
Is my input saved?
No. It stays in browser memory and clears on refresh. Successful actions record only a stable tool ID and name, never your entered data.