Regex Tester
Workspace
This workspace processes the content directly in your browser.
Formatting, decoding, validation, and common file work stay local whenever possible, then continue in the same result area for copy, download, or the next step.
Paste content, choose a file, or load a sample first.
The content stays in the local browser by default.
After processing, copy, download, or continue into a related workflow.
Input
Result
Live matches, capture groups, and replacement previews will appear here.
Test JavaScript regular expressions with live sample text, match details and replacement previews in one page.
Common tasks
- Validate patterns before coding
- Check capture groups quickly
- Preview replace rules on sample content
A technical article on how Base64 turns bytes into text, why padding exists, how URL-safe variants differ, and why Base64 is not encryption.
Hex and Bytes Explained: Reading File Headers, Encodings, and Binary CluesA technical guide to hexadecimal inspection, byte order, file signatures, BOM markers, and why byte-level debugging helps with format problems.
JSON and CSV Are Not Equivalent: What Gets Lost During ConversionA practical technical article on converting between JSON and CSV, including nesting, headers, quoting, nulls, types, and spreadsheet assumptions.
Key Questions
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