regex101: Online Regex Tester, Builder, Converter & Debugger

Regular Expressions 101

Pro

Understand your regular expression with detailed explanations of its tokens, groups, and flags. Regex conversion adapts patterns, flags, and replacement text between any supported flavors, with compatibility checks and a breakdown of changes.

Supports:

PCRE2 (PHP)
JavaScript
Python
Golang
Java
.NET 10.0 (C#)
Rust
POSIX ERE
POSIX BRE (grep/sed)
PCRE (Legacy)

See what matched and what each group captured, including named groups and values reusable in replacements or backreferences. Investigate unexpected results with the regex debugger and export them to JSON, JSON Lines, CSV, or Plain Text afterwards.

25 tokens

Regular Expression

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