Regex Tester
Write and test regular expressions with real-time highlighting, capture groups & match details. Instant results as you type.
📚 Quick Reference — Click to expand
| Pattern | Description | Example |
|---|---|---|
| . | Any character except newline | a.c → abc, aXc |
| d | Digit [0-9] | d+ → 123 |
| w | Word char [a-zA-Z0-9_] | w+ → hello_1 |
| s | Whitespace | asb → a b |
| ^ | Start of string/line | ^Hello |
| $ | End of string/line | world$ |
| * | 0 or more | ab*c → ac, abc |
| + | 1 or more | ab+c → abc, abbc |
| ? | 0 or 1 | colou?r → color, colour |
| {n,m} | Between n and m times | a{2,4} → aa, aaa |
| [abc] | Character class | [aeiou] → vowels |
| (abc) | Capture group | (w+)@(w+) |
| a|b | Alternation (or) | cat|dog |
| b | Word boundary | bwordb |
| (?=...) | Positive lookahead | d(?=px) |
| (?!...) | Negative lookahead | d(?!px) |
How to Use
- Enter your regex pattern in the pattern field (between the slashes).
- Set flags — g (global), i (case insensitive), m (multiline), s (dotall).
- Type or paste your test string in the text area.
- Matches are highlighted in real time as you type.
- View detailed match info including capture groups on the right panel.
Features
Real-Time
Matches highlight instantly as you type pattern or text.
Highlighting
Visual match highlighting with alternating colors.
Capture Groups
See captured groups for each match with index positions.
Quick Reference
Built-in regex cheat sheet for common patterns.
Use Cases
- Form Validation: Test email, phone, URL patterns before using in code.
- Data Extraction: Build patterns to extract specific data from text.
- Search & Replace: Test find-replace patterns before applying.
- Log Parsing: Create patterns to parse server logs and error messages.
- Learning: Understand regex by experimenting with patterns and seeing results.
Benefits
- Instant visual feedback with match highlighting.
- Detailed capture group information for each match.
- Built-in cheat sheet for quick reference.
- Supports all JavaScript regex features and flags.
- 100% private — everything runs in your browser.
Mastering Regular Expressions
Regular expressions are powerful pattern-matching tools used across virtually every programming language. They enable complex text searching, validation, and transformation operations that would require dozens of lines of code to accomplish otherwise. The NearMeTool Regex Tester gives you a visual sandbox to build and test patterns with instant feedback.
Common Regex Patterns
Some of the most useful patterns include email validation ([w.-]+@[w.-]+.w+), URL matching (https?://[w.-]+), phone numbers (d{3}[-.]?d{3}[-.]?d{4}), and IP addresses (d{1,3}.d{1,3}.d{1,3}.d{1,3}). This tool helps you test and refine these patterns against real data before using them in production.
Developer Workflow
Once you have perfected your regex pattern, implement it in your application using the Online Code Editor. If your regex processes JSON data, validate it first with the JSON Validator. For JavaScript development, check your code syntax with the JavaScript Validator. Generate test data with unique IDs using the UUID Generator.
Frequently Asked Questions
Does it support all regex features?
It supports all JavaScript regex features including lookahead, lookbehind, capture groups, named groups, and all flags (g, i, m, s, u, y).
Does it highlight matches in real time?
Yes, matches are highlighted instantly as you type in either the pattern or test string field.
What do the flags mean?
g = global (find all matches), i = case insensitive, m = multiline (^ and $ match line boundaries), s = dotall (. matches newlines).
Can I see capture groups?
Yes, each match shows its capture groups with index positions and matched text.
Is my data secure?
Yes, everything runs locally in your browser. No data is sent to any server.
Does it work with other languages' regex?
The tool uses JavaScript's regex engine. Most patterns are compatible across languages, but some features like lookbehind may differ.
Is it free?
Yes, 100% free with no limits.