Developer Tools
Extract JS Regex Literals
Extract regular expression literals from pasted JavaScript, TypeScript, JSX, or TSX source without executing, compiling, evaluating, testing, or uploading code.
0 / 30,000 characters. No upload, storage, or account required.
JS Regex Literals workflows
Use this extractor when copied source needs a browser-local inventory of validation, parsing, masking, security-review, or route-matching patterns before code review.
Audit validation behavior
Pair extracted regexes with Extract JS Error Messages, Extract JS Test Case Names, and Regex Tester before changing validation rules.
Review strings and constants
Use Extract JS String Literals, Extract JS Numeric Literals, and Extract JS Variable Names.
Clean copied output
Send extracted rows to Sort Lines, Remove Duplicate Lines, or Normalize Whitespace.
What this tool does
Extract JS Regex Literals scans pasted source as text, lists each /pattern/flags literal with source lines, removes duplicates, and runs locally in your browser.
Common use cases
Extract JavaScript regular expression literals from pasted JavaScript, TypeScript, JSX, TSX, validator files, route matchers, parsing helpers, tests, generated code, or copied source before behavior audits, migration planning, QA reviews, documentation, or handoffs.
Use Extract JS Regex Literals when you are working with copied API payloads, logs, encoded values, config snippets, identifiers, or debugging data and need a quick browser-local check before pasting the result into docs, tickets, tests, or another developer tool.
How to use it
- Paste JavaScript, TypeScript, JSX, TSX, tests, validators, route matchers, copied snippets, or generated source that may contain regex literals.
- Choose whether duplicate rows should be removed and whether extracted literals should be normalized for comparison.
- Review extracted regex literals with line numbers, then copy the clean list for audits, migration notes, QA checklists, documentation, or handoffs.
Example workflow
Copy a small payload or encoded value from an API response, request URL, log line, or config file. Run the focused check here, confirm the output is readable, then continue with related developer data tools such as validation, formatting, decoding, timestamp conversion, or CSV/JSON conversion.
Privacy note
Extract JS Regex Literals runs locally in your browser. Your pasted code is not uploaded, compiled, evaluated, tested, executed, stored, or logged.
Practical notes for this tool
Best use case
Use Extract JS Regex Literals when validators, route matchers, masking helpers, or tests need a quick regex inventory before changing validation behavior or writing QA notes.
Collect validation patterns before signup changes
const email = /[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}/gi;
const slug = /^[a-z0-9]+(?:-[a-z0-9]+)*$/;
if (/^admin\//.test(path)) return null;/[A-Z0-9._%+-]+@[A-Z0-9.-]+\.[A-Z]{2,}/gi
/^[a-z0-9]+(?:-[a-z0-9]+)*$/
/^admin\//Privacy and local processing
Regex literal extraction happens locally and does not execute code, evaluate patterns against external data, upload snippets, or store source.
Limitations to know
- It does not parse every possible regex construction.
- It does not detect RegExp constructor strings.
- Complex or security-sensitive regexes should be reviewed and tested separately.
Practical FAQ
Will this test whether a regex is safe or correct?
No. It inventories regex literals only. Test behavior separately with representative inputs, code review, and performance checks before changing validation rules.
Related workflow links
FAQ
Does Extract JS Regex Literals execute JavaScript?
No. It scans pasted source as text and does not execute code, compile TypeScript, evaluate regular expressions, test matches, upload, store, or log snippets.
Which regex patterns are included?
It finds common JavaScript /pattern/flags literals in pasted JavaScript, TypeScript, JSX, TSX, validator, parser, route matcher, and test snippets.
When is this useful?
Use it while preparing validation inventories, behavior audits, migration notes, QA checklists, documentation, release notes, or copied-source handoffs.
Explore more tools
Browse the Developer Tools hub or continue with the Developer Data Toolkit when this task is part of a larger workflow.