JavaScript regex explained in plain English

Paste a RegExp pattern and flags; get a structured Markdown breakdown of anchors, character classes, groups, and quantifiers—parsed locally.

Paste or type a pattern and optional flags. The page parses your expression and outputs a structured explanation you can copy as Markdown.

Pattern

index.txt

text

Flags

Only g, i, m, s, u, v, y, d are kept. Invalid combinations (for example v with u) show as a runtime error from the engine.

Match in sequence (left to right):
- One or more times (+). Greedy: take as many as possible first.
  - Expression fragment: \d.
- Zero or more times (*). Greedy: take as many as possible first.
  - Expression fragment: \s.

index.txt

text

Flags

Only g, i, m, s, u, v, y, d are kept. Invalid combinations (for example v with u) show as a runtime error from the engine.