How many examples should I give?

Aim for 3-5 positive examples that cover the variation you want to match, and 2-3 near-miss negatives. The more varied and realistic the examples, the tighter the generated regex. Too few examples produce overly loose patterns; too many similar examples waste tokens.

What regex engines does the output work with?

The tool generates POSIX/PCRE-compatible patterns that work in JavaScript, Python, Go, Ruby, and most modern regex engines. If you need a specific dialect (like Vim, .NET, or grep basic), you may need to tweak character classes or anchors.

Will it always match my examples exactly?

The prompt instructs Nova to mentally test the regex against every example before answering, but AI output is not guaranteed. Always verify the generated regex against your real data. For critical matching logic, use the regex as a first draft and test thoroughly.

Why not just write the regex myself?

If you already know regex well, you probably don't need this. But many developers recognize regex they didn't write faster than they write it from scratch. This tool compresses the think-and-test loop into a 3-second round trip.

No. The examples are sent to Amazon Nova Micro on AWS Bedrock to generate the regex. No logs, no storage. Only an aggregate request counter for daily-cap bookkeeping.

Regex from Examples

Paste a few example strings that should match and a few that shouldn't — the tool generates a regex pattern that handles both, plus a one-line plain-English explanation of what it matches. Works for emails, phone numbers, log line patterns, URL shapes, IDs, or any custom string format. Powered by Amazon Nova Micro on AWS Bedrock.

Give 3-5 strings that should match and 3 that shouldn't. Nova Micro generates a readable regex that fits. Free, daily-capped.

Should MATCH (one per line)

Should NOT match (one per line)

51 / 3,000 characters

Tips for better results

• Give at least 3-5 matching examples that vary
• Include near-miss negatives (subtle differences)
• One string per line, no commas or quotes
• The more varied your matches, the tighter the regex
• Test the output against your real data
• Works for any engine (JS, Python, Go, PCRE)

Next useful step

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Frequently Asked Questions

How many examples should I give?: Aim for 3-5 positive examples that cover the variation you want to match, and 2-3 near-miss negatives. The more varied and realistic the examples, the tighter the generated regex. Too few examples produce overly loose patterns; too many similar examples waste tokens.
What regex engines does the output work with?: The tool generates POSIX/PCRE-compatible patterns that work in JavaScript, Python, Go, Ruby, and most modern regex engines. If you need a specific dialect (like Vim, .NET, or grep basic), you may need to tweak character classes or anchors.
Will it always match my examples exactly?: The prompt instructs Nova to mentally test the regex against every example before answering, but AI output is not guaranteed. Always verify the generated regex against your real data. For critical matching logic, use the regex as a first draft and test thoroughly.
Why not just write the regex myself?: If you already know regex well, you probably don't need this. But many developers recognize regex they didn't write faster than they write it from scratch. This tool compresses the think-and-test loop into a 3-second round trip.
Is my input stored?: No. The examples are sent to Amazon Nova Micro on AWS Bedrock to generate the regex. No logs, no storage. Only an aggregate request counter for daily-cap bookkeeping.

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About Regex from Examples

Give 3-5 strings that should match and 3 that shouldn't. Nova Micro generates a readable regex that fits. Free, no login. This AI-backed tool sends your input to MarkdownMe's capped Amazon Bedrock endpoint to generate the result. No account is required. MarkdownMe provides free, fast, and reliable Markdown tools for developers, writers, and anyone who works with Markdown.