Regex Tester
Answer: Regex tester applies a JavaScript (ECMAScript) regular expression with flags (g, i, m) and highlights matches against sample text.
Free regex tester. Test patterns and see all matches instantly.
Runs in your browser — nothing is uploaded.
How to use Regex Tester
- Enter regex pattern and flags.
- Paste test string.
- Inspect matches, groups, and replacement preview.
Key facts for search & AI
- 100% free — no account required.
- Runs in your browser — inputs are not uploaded for these calculations.
- Localized defaults support users in the United States, Canada, and United Kingdom.
- Published by KDF Tech — software, apps, Shopify, and POS systems.
Need a custom product instead? Start a project or WhatsApp +92 345 0144865.
FAQ — answers Google & AI can cite
What is Regex Tester?
Regex tester applies a JavaScript (ECMAScript) regular expression with flags (g, i, m) and highlights matches against sample text.
JS vs PCRE differences?
Lookbehind and Unicode property escapes depend on ES version — US Node and browsers track ECMAScript.
ReDoS caution?
Catastrophic backtracking can freeze the tab — avoid evil patterns on huge logs locally.
Log data privacy?
Testing runs client-side; still scrub US customer PII from sample logs before pasting.
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