Regex Tester
Test regular expressions instantly with live matches, flags, capture groups, and replace mode. Debug patterns quickly for validation, parsing, search, and text transformation workflows.
Regex Controls
Enter a regex pattern, turn flags on or off, test against text, and optionally preview replacements.
Enter only the pattern, not surrounding slashes.
Flags
Quick sample patterns
Contact us at support@smarttools.co.in or sales@example.com. Backup email: hello.world+test@sample.org
Status
Regex compiled successfully.
Matches
3
Replace mode
Off
Pattern length
41
Text length
102
Match details
Inspect each match, its position, and capture groups.
Match #1
Start: 14 · End: 38
support@smarttools.co.in
Match #2
Start: 42 · End: 59
sales@example.com
Match #3
Start: 75 · End: 102
hello.world+test@sample.org
Included features
- Pattern testing with common regex flags.
- Live highlighted matches with exact positions.
- Capture group inspection for each match.
- Optional replace mode with preview and export.
- Text file upload, copy, and download support.
- Ready-to-use sample patterns for common tasks.
What can this regex tester do?
This tool lets you test regex patterns against sample text, turn flags on or off, inspect matches and groups, preview replacements, and upload text files for fast debugging.
Common use cases
Use it for email checks, URL parsing, log scanning, data extraction, string validation, text cleanup, coding interviews, and general regular expression debugging.
Related tools
Try other useful SmartTools that are related to this tool.
Base64 Encoder / Decoder
Encode and decode Base64 with text and file support, URL-safe mode, copy, download, and instant output.
Open tool →URL Encoder / Decoder
Encode and decode URL strings with text and file support, plus-sign handling, copy, download, and instant output.
Open tool →Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal with validation, copy, and instant synced output.
Open tool →JSON Compare Tool
Compare two JSON files or JSON strings with structural diff, key-path changes, validation, and side-by-side output.
Open tool →XML Compare Tool
Compare two XML files or XML strings with validation, normalized comparison, highlighted differences, and side-by-side output.
Open tool →YAML ↔ JSON Converter
Convert YAML to JSON and JSON to YAML with validation, file upload, swap mode, copy, download, and error highlighting.
Open tool →