Regex Tester
Test a JavaScript regular expression against sample text with flags, match highlighting and captured-group output.
[
{
"match": "API",
"index": 0,
"groups": []
},
{
"match": "HTTP",
"index": 18,
"groups": []
},
{
"match": "SERVER",
"index": 23,
"groups": []
}
]Turn this result into a calculation record
Carry the tool context into the PROFENG calculation-check and record workspace without implying certification or engineering approval.
Formula source and acknowledgement
Source being confirmed. PROFENG has not yet approved a published source for this exact calculator implementation, so no candidate book, paper or standard title is displayed here.
Credit for any underlying published method belongs to its original author(s) or standards body. PROFENG presents its own implementation and wording and does not imply endorsement or affiliation.
Read the PROFENG methodology for formula sourcing and automated checks →
Why use this regex tester?
Test a JavaScript regular expression against sample text with flags, match highlighting and captured-group output. It is designed as a focused browser utility so you can test a scenario or transform data without creating an account.
Example
Paste a small representative sample into Regex Tester, review the generated result, then copy it into your development or data workflow after checking the output.
Important note
Generated developer output should be reviewed before production use. Keep secrets, credentials and sensitive production data out of browser tools unless you control the environment and understand the risk.
How to use it
Start with the inputs shown above, review the assumptions or options, then generate the result. Where the tool creates a file, keep the original until you have opened and checked the downloaded output.
Frequently asked questions
Is Regex Tester free?
Yes. The core tool is free to use without creating an account.
Do I need an account to use Regex Tester?
No. You can use the core Toolbox workflow without signing up.
Does Regex Tester work on mobile?
Yes. Toolbox is designed for modern mobile and desktop browsers, although complex file workflows can be easier on a larger screen.
QA, changelog and corrections
Last QA update: 30 September 2026.
This page is covered by publication and metadata QA only unless a tool-specific automated verification status is displayed above. No named-expert review is claimed.
Changelog
30 September 2026 – source/indexation status, metadata and correction pathway reviewed. Engineering tools display the automated verification label only when they are inside the passing Part 3 verification scope.