DevBolt
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Safe Regex Tester — Test Patterns Without Exposing Your Data

Test regular expressions against your data with complete privacy. DevBolt's regex tester runs entirely in your browser — your test strings, log data, and source code snippets are never sent to any server.

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Regex Tester

Test regular expressions in real time with match highlighting and capture groups.

//g

Matches (0)

Enter a pattern and test string to see matches

Why regex tester privacy matters

When testing regex patterns, you paste real data as test input: log file entries containing IP addresses and usernames, source code with embedded strings and API endpoints, email lists for validation testing, user-submitted form data for pattern matching, and server access logs with authentication details. Server-based regex testers like regex101 transmit your test data to their backend for processing and pattern library features. DevBolt uses JavaScript's native RegExp engine to execute patterns entirely in your browser — your test data stays private.

Safe for testing against production data

Building regex patterns for log parsing, data extraction, or input validation often requires testing against real production samples. With DevBolt, you can paste production log entries, real customer data, or internal source code as test input without worrying about data exposure. The regex engine is JavaScript's built-in RegExp — the same engine your production code uses. Results are highlighted in real-time as you type, with zero network involvement.

Client-side regex execution

DevBolt creates a JavaScript RegExp object from your pattern and executes it against your test string using the native regex engine. Match results, capture groups, and highlighting are all computed in your browser. There is no server-side regex engine, no pattern saving to a remote database, and no sharing of your test data. You can verify this in the DevTools Network tab.

Frequently Asked Questions

Is it safe to test regex against real data?

With DevBolt, yes. The regex engine runs entirely in your browser using JavaScript's native RegExp. Your test strings — whether log entries, customer data, or source code — are never transmitted to any server.

How is this different from regex101?

regex101 is a powerful tool but transmits data to its server for features like pattern libraries and community sharing. DevBolt runs 100% client-side with no server component — simpler, but completely private.

Does the regex tester work offline?

Yes. After your first visit, DevBolt caches the tool via service worker. You can test regex patterns offline, confirming that no server connection is needed.

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