Regex Tester
Test regex patterns against sample text, inspect matches, and catch syntax errors immediately.
Regex Tester gives you a direct space to iterate on patterns, flags, and sample input without losing track of matches or syntax errors.
What is Regex Tester?
Regex Tester gives you a direct space to iterate on patterns, flags, and sample input without losing track of matches or syntax errors.
Use it to test a Regex against representative text before adding the pattern to Log parsing, validation or extraction code.
How to use Regex Tester?
Step 1
Try the included example input, then replace it with a redacted sample from the system you are debugging.
Step 2
Enter the pattern and any flags.
Step 3
Paste test text into the sample area.
Step 4
Review matches, highlighted segments, and total count.
Example input / output
Test a trace-ID pattern against both matching and non-matching Log lines, then check flags and escaping in the target programming language.
Review the result for completeness before copying it into code, a test, a ticket or another tool.
Example input
\b[A-Z]{2,}-\d{3}\bExample output
The tool returns a readable, copy-ready result based on the selected action.Practical developer examples
Extract correlation IDs
Test a pattern against several Log formats before using it in an alert, parser or support script.
Validate an input rule
Include valid, invalid and boundary examples so a pattern does not silently reject real user or API data.
Common developer use cases
A Regex can match the sample and still fail in production because of anchoring, flags, escaping, greediness or engine differences. Test realistic counterexamples, not only the happy path.
Common issues
FAQ
Does Regex Tester send data to a server?
The interactive transformation is handled in the browser in this frontend build. Analytics and advertising scripts may still load separately for site measurement or ads readiness, so avoid pasting active secrets or regulated personal data.
What input works best in regex tester?
Paste raw regex patterns and sample text directly into the input area or use the example button for a quick starting point.
Can I share Regex Tester output with teammates?
Yes, but review the result first and redact tokens, private keys, customer data, internal URLs, account IDs, and other sensitive values before sending it in a ticket, chat, or pull request.