RegExr
Focus: patterns. Shares regex and developer tools with regex101. Rated 4.7 (regex101: 4.8).
Web AppFreeWeb
4.7Visit
Web App
regex101
An online tester that builds, explains and debugs regular expressions.
Rating
4.8 / 5
Pricing
Free
Difficulty
Intermediate
Works on
Web
Built with love by Shushant Lakhyani. Building bestproductivityresources.com
What is regex101?
regex101 is a free online tool for writing and testing regular expressions with live matching and a plain-language explanation of each part. It supports flavours such as PCRE2, JavaScript, Python, Go, Java and .NET, and lets you save and share patterns with a link.
Pros: what regex101 does well
- Explains every part of a pattern
- Supports many regex flavours
- Shareable saved patterns
Cons: where it falls short
- Can feel busy for beginners
- Some extras need a free account
Who regex101 is for
Developers and analysts who write or debug regular expressions.
Who can skip it
People who never work with text patterns or code.
regex101 alternatives
Not sold on regex101? These do a similar job, and each card says what it has in common.
Regexper
Focus: diagrams. Shares regex and developer tools with regex101. Rated 4.6 (regex101: 4.8).
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JWT.io
Focus: jwt and authentication. Shares debugging and developer tools with regex101. Rated 4.6 (regex101: 4.8).
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Webapp Testing Skill
Focus: claude, claude skills and playwright. Shares testing and debugging with regex101. An AI tool, not a web app. Adds macOS, Windows and Linux. Same 4.8 rating.
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DevDocs
Focus: documentation, api reference and open source. Shares developer tools with regex101. Adds Offline. Rated 4.7 (regex101: 4.8).
Web AppFreeWeb, Offline
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JSONPlaceholder
Focus: fake api, rest and json. Shares testing with regex101. Rated 4.7 (regex101: 4.8).
Web AppFreeWeb
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Free alternatives to regex101
Want to spend nothing? These free picks cover similar ground.
The Missing Semester
Focus: command line, git and mit. Shares developer tools with regex101. A course, not a web app. Same 4.8 rating.
CourseFreeWeb
4.8Visit
GitHub Student Developer Pack
Focus: students, free credits and education. Shares developer tools with regex101. A website, not a web app. Rated 4.7 (regex101: 4.8).
WebsiteFreeWeb
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Insomnia Mockbin
Focus: api, mock server and http. Shares testing and debugging with regex101. Rated 4.6 (regex101: 4.8).
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httpbin
Focus: http and api testing. Shares debugging and developer tools with regex101. Rated 4.5 (regex101: 4.8).
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4.5Visit
JupyterLab
Focus: notebooks, python and data science. Also in Learning and Workflows, like regex101. Adds macOS, Windows and Linux. Rated 4.7 (regex101: 4.8).
Web AppFreeWeb, macOS
4.7Visit
CSS Grid Generator
Focus: css grid, layout and front end. Also in Learning and Workflows, like regex101. Rated 4.6 (regex101: 4.8).
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