Regex Builder

Reference

How does the regex builder work?

Each block represents a regex token. Blocks are composed left-to-right, with quantifiers attached to the previous block. The result is a valid JavaScript regex you can test against any input. This visual approach is great for learning regex without memorizing the cryptic syntax of \d, [a-z], {2,4}.

Common uses

• Form validation — build email, phone, or zip patterns visually.
• Log parsing — extract structured fields from raw logs.
• Learning — bridge from blocks to syntax.
• Quick prototyping — validate ideas before writing code.

Privacy

All matching runs 100% in your browser. No data is sent to any server.