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Regex Generator

AI regex generator

GPTExcel's regex generator writes a regular expression from a plain-English description, in the flavor your language uses: JavaScript, PCRE (PHP / Perl), Python, .NET, Java, or Go. It also explains existing patterns token by token, and you can test a pattern against sample text right away.

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How it works

From plain English to a tested pattern

  1. 1

    Pick the regex flavor

    Choose JavaScript, PCRE (PHP / Perl), Python (re), .NET, Java, or Go (RE2), so the pattern only uses syntax your engine supports.

  2. 2

    Describe what to match

    Explain the text you want to match or capture, e.g. “Capture the year, month, and day from an ISO date”.

  3. 3

    Generate the pattern

    GPTExcel returns the raw pattern, any flags it needs, and a breakdown of what each part does.

  4. 4

    Test it

    The generated pattern drops into the built-in tester, where you paste sample text, toggle flags, and see every match and capture group. The tester runs in your browser's JavaScript engine.

Example

One prompt, one result

A typical request and the kind of answer the Regex tool returns. AI output varies, so check it against your own data before you rely on it.

Flavor: JavaScript

Capture the year, month, and day from an ISO date

Generated pattern

A pattern that matches an ISO 8601 date like 2026-09-24 and captures each part in a named group.

^(?<year>\d{4})-(?<month>0[1-9]|1[0-2])-(?<day>0[1-9]|[12]\d|3[01])$
  • (?<year>\d{4}) captures a four-digit year
  • (?<month>0[1-9]|1[0-2]) captures a month from 01 to 12
  • (?<day>0[1-9]|[12]\d|3[01]) captures a day from 01 to 31
  • ^ and $ anchor the match to the whole string; add the m flag to match one date per line

Supported flavors

Written for the tool you actually use

Every mode works with every option below: Generate, Explain, Optimize.

  • JavaScript

  • PCRE (PHP / Perl)

  • Python (re)

  • .NET

  • Java

  • Go (RE2)

Frequently asked questions

Which regex flavors are supported?
JavaScript, PCRE (PHP / Perl), Python (re), .NET, Java, and Go (RE2). Choose the flavor before you generate so the pattern avoids syntax your engine doesn't support.
Can I test the pattern before using it?
Yes. The regex tool includes a tester: paste sample text, toggle the g, i, m, s, and u flags, and see each match with its capture groups. The tester runs in your browser's JavaScript regex engine.
Can it explain a regex I found somewhere else?
Yes. Paste the pattern into Explain mode for a token-by-token breakdown, or into Optimize mode to simplify it and remove catastrophic backtracking.
Is the regex generator free?
Yes, you can start free. The free plan includes 4 tool runs every 12 hours, shared across the Formula, Script, SQL, Regex, and Template tools, and paid plans raise that limit. You need a free GPTExcel account to use it.
GuideDecoding and generating regex with AI

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