Skip to content
browserutils

Regex Visualizer

Visualize regex as a railroad diagram with explanations

Regex Visualizer is a free online tool from BrowserUtils that visualize regex as a railroad diagram with explanations. It runs entirely in your browser — your data never leaves your device. No account required.

//g

Enter a regex pattern above to see its railroad diagram and explanation.

How to use Regex Visualizer

  1. 1 Paste or type your input into the editor above.
  2. 2 The tool processes your data instantly — right in your browser, with nothing sent to a server.
  3. 3 Copy the result with one click or continue editing your input.

About Regex Visualizer

Free online regex visualizer. See your regular expression as a railroad diagram with an English explanation of each part, plus live match testing. This tool runs entirely in your browser — your data is never sent to a server. Just paste your input, get instant results, and copy with one click. No sign-up or installation required.

Regex Visualizer specs

Runtime
100% client-side (browser)
Built on
Native JavaScript String, Intl.Segmenter, and RegExp APIs with full Unicode support
Cost
Free — no account, no rate limits, no usage caps
Browser support
Chrome 90+, Firefox 88+, Safari 14+, Edge 90+
Part of
299 developer tools on BrowserUtils (100% client-side)

Questions

What is a railroad diagram?
A railroad diagram is a visual representation of a grammar or pattern. For regex, it shows the flow of matching as a diagram with paths for alternatives, loops for quantifiers, and labeled boxes for character classes and literals.
Does it support all regex features?
The visualizer supports common regex features including literals, character classes, quantifiers, groups, alternation, and anchors. Some advanced features like backreferences have simplified representations.
How is the regex visualizer different from the regex tester?
The regex tester highlights matches in sample text for debugging. The visualizer generates a railroad diagram that shows the structure and flow of the pattern itself, which helps you understand how the regex engine processes it.
Can I use the regex visualizer to learn regular expressions?
Yes, the visual diagram and plain-English explanation make it easier to understand how regex patterns work, especially for beginners who find raw regex syntax difficult to read.
Does the regex visualizer send my pattern to a server?
No, the diagram is generated entirely in your browser. Your regex patterns are never transmitted to any external service.
Embed this tool

Copy this code to embed the tool on your website. Adjust the height to fit your layout.

<iframe src="https://www.browserutils.dev/embed/regex-visualizer" width="100%" height="500" frameborder="0" title="Regex Visualizer"></iframe>

Related tools

More Text & String Utilities

View all Text & String Utilities tools