Tool

Regex tester for bot commands and message parsing

Patterns run in a separate Web Worker with a time limit, so a runaway expression cannot freeze the page, the same protection your bot should have.

Pattern

Presets

Test text

Highlighted matches

Matches and groups

Replace with

Replace result

Code

Regex safety for bots

Anchor command patterns with ^ and $ so "/startx" does not trigger /start.
Avoid nested quantifiers such as (a+)+ or (.*)*, which explode on crafted input (ReDoS). Limit input length before matching.
Never build a pattern from user input without escaping it.
Prefer the platform's structured data (Telegram entities, Discord interaction options) over parsing raw text.