3-Tools.com

Free Online Regex Checker

Instantly check if your regex is valid and understand its components.

About

This tool helps you verify if your regular expressions are valid and provides a detailed breakdown of their components. To use it, simply enter your regex pattern in the text area and click "Check". You'll receive instant feedback on its validity and suggestions for corrections if needed.

Practical Examples:

  • Check if a pattern can successfully match an email format.
  • Verify regex patterns used in form validations.
  • Understand complex regex components with a detailed breakdown.

Quick Reference

Simple email validation ^[\w.%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,}$
Basic URL check ^(https?|ftp)://[^\s/$.?#].[^\s]*$
Match digits only ^\d+$

Related Tools

Most Popular

Upgrade to Pro

Unlimited usage & power features — less than a coffee per week

Free

  • ✓ 5 uses per day
  • ✓ Basic features
  • ✗ No batch processing
  • ✗ No priority support

Pro — €9/mo

  • Unlimited uses
  • ✓ All features unlocked
  • ✓ Batch processing
  • ✓ Priority email support
Get Pro Access →

Cancel anytime · Secure payment via Stripe · Instant activation

⚡ Love this tool? Get more with Pro

3-Tools Pro €9/mo

Unlimited usage, no ads, priority features & early access to new tools.

Related Tools

💡 Need automated monitoring?

UptimeRobot Partner

Monitor your websites, APIs, and servers 24/7. Free plan available.

🛠️ Get new free tools every week

Join 3-Tools newsletter — no spam, unsubscribe anytime.