How do I build a regex without typing the syntax?

Click the building blocks in each group: anchors, character classes, quantifiers and groups. Each click inserts the matching syntax into the pattern box at your cursor position, so you build the expression step by step without memorising the syntax.

How do I know if my pattern is valid?

The builder checks your pattern as you type. If it is invalid, it shows the exact error message from the JavaScript engine, such as an unbalanced parenthesis, so you can fix it right away.

What do the flags g, i, m, s and u mean?

The g flag finds all matches instead of stopping at the first. The i flag ignores upper and lower case. The m flag makes the start and end anchors work per line. The s flag lets the dot match newlines too. The u flag enables full Unicode matching.

Visual Regex Builder

Build a regular expression by clicking blocks instead of memorising syntax. Test it live on your own text, see every match highlighted, and read a plain English explanation of what your pattern means.

1. Click blocks to build your pattern

Anchors

Character classes

Quantifiers (apply to the block before them)

Groups

Pattern

Flags

g all

i case

m lines

s dotall

u unicode

2. Test on your text 0 matches

Test string

Matches

3. What does it mean? plain English explanation

Token	Meaning

Build or type a pattern to see each part explained.

How to use

Click the blocks to build your pattern, or type directly into the pattern box. The validity line tells you instantly if the pattern has an error.
Toggle the flags to change how matching works, for example g for all matches or i to ignore case.
Paste your own test text and watch the matches highlight with a count.
Read the explanation table to check each part of your pattern does what you intended.

Unlike a plain regex tester, this tool is built for learning: you assemble the pattern from blocks and get a plain English breakdown of every token. Nothing leaves your browser.

Visual Regex Builder

How to use

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