Developer Tools
Regex Tester
Test regex patterns against pasted sample text and review browser-local match positions and capture groups.
Output will appear here.
Regex testing workflow tips
Use this tester for quick pattern debugging before applying a regex in a replacement, extraction, line filter, code search, or validation workflow.
Escape literal text first
When matching URLs, filenames, or punctuation literally, prepare the source with Regex Escape Tool.
Extract clean match lists
After the pattern looks right, use Regex Match Extractor to copy one match per line.
Use patterns in cleanup
Apply tested patterns in the Developer Data Toolkit, Find and Replace Text, Filter Lines, or targeted extractors like Extract Emails.
Quick answer
Regex Tester is a browser-based regex tester for checking copied developer data such as payloads, URLs, encoded values, identifiers, snippets, or logs without sending the input to a server.
- Primary task
- regex tester
- Processing
- Runs on copied snippets in your browser; no account or saved input.
- Workflow
- Developer Data Toolkit
What this tool does
Regex Tester runs a JavaScript regular expression against pasted text in your browser, then reports matches, indexes, and capture groups so developers and content operators can debug patterns before using them in cleanup or code workflows.
Common use cases
Validate and debug regular expressions quickly by testing patterns against sample text and reviewing captured matches.
Use Regex Tester 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 sample text, logs, labels, URLs, or content you want to test against.
- Enter a regex as /pattern/flags or as a plain pattern.
- Review the match report, capture groups, and match count before copying results or refining the pattern.
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
Client-side only: regex testing runs in your browser. ClearUtils does not upload, store, fetch, log, or inspect pasted text.
FAQ
These answers focus on copied-snippet workflows, safe sample data, validation boundaries, and what to check before moving output into code, APIs, docs, or tickets.
3 focused answers for this page
Can I test regex flags in this tool?
Yes. Paste either /pattern/flags syntax or a plain pattern to default to case-sensitive global matching in-browser.
Can I see capture groups?
Yes. Capture groups are shown for matches that include parenthesized groups.
Does this upload my text?
No. Regex testing runs locally in your browser, and your text is not uploaded or stored.