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Regex Visualizer - Free Online Regex Railroad Diagram Tool | IconVault

Understand any regex: railroad diagram, plain-English explanation and live match tester. Paste a pattern and see what it really matches. Free, in your browser.

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Regex Visualizer

Railroad diagrams plus plain-English regex

5 of 5 free uses left
//

Railroad diagram

Group 1\d digit{3}-Group 2\d digit{4}

JavaScript (ECMAScript) flavor. Loops show repeats, bypass lines show optional parts.

Plain-English explanation

  1. 1Group 1 containing: Match a digit (0-9), repeated exactly 3 times
  2. 2Match the literal text "-"
  3. 3Group 2 containing: Match a digit (0-9), repeated exactly 4 times

Test string

2 matches
Call 555-1234 or 555-9876 today

5 of 5 free copies left - the diagram, explanation and tester are unlimited.

About this tool

IconVault's Regex Visualizer turns cryptic patterns into something you can actually read. Paste any JavaScript regex and get a railroad diagram that lays the pattern out as a flowchart, a plain-English explanation of each token, and a live tester that highlights matches in your sample text.

It is perfect for decoding inherited patterns, learning regex by example, and debugging why a pattern matches too much or too little. Everything renders instantly in your browser, and the tool is free with no signup.

Frequently asked questions

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