Regex Generator

The Regex Generator helps you compose regular expressions from intuitive options. Instead of memorizing syntax, you choose anchors, character classes, and flags, and the tool assembles a working pattern. Copy the final /pattern/flags output or a JavaScript snippet in a click.

Use it to draft quick validators (usernames, tags, simple tokens) or to bootstrap patterns you can refine later in your editor. The generator supports start/end anchors, letters/digits/spaces classes, and the case‑insensitive flag.

Key features

• Toggle anchors (^, $) and flags (i)
• Compose character classes for letters, digits, and spaces
• Optional custom body to paste your own group or quantifier
• Copy as /pattern/flags or as new RegExp() snippet
• Local persistence of pattern and options

Common use cases

• Quickly drafting patterns for form validation
• Testing simple matchers before pasting into code
• Teaching the anatomy of basic regex components

Privacy & security: everything runs locally in your browser; no data is uploaded.

1. Toggle start/end anchors if you want to match the whole string.
2. Enable character classes such as letters and digits.
3. Optionally paste a custom body like [A-Za-z0-9_-]{3,16}.
4. Enable the i flag for case‑insensitive matches.
5. Click “Copy Regex” or “Copy as JS” to paste into your project.
6. Use “Sample” to prefill a common username pattern.
7. Clear to start from a blank slate.

Tips

• Prefer explicit character sets to avoid unexpected matches.
• Use quantifiers like {3,16} to constrain length.
• Test in multiple environments; engine details can vary.

Troubleshooting

• Pattern matches too much → Add anchors or narrow the class.
• Unexpected errors → Ensure brackets and braces are balanced.
• Flags not applied → Confirm the i toggle is on before copying.