Text Diff Checker
Text Diff Checker compares two versions of text line by line and highlights what was added and removed — useful for proofreading, code and config changes.
Last updated: July 2026
Compare two blocks of text and see added and removed lines highlighted. Free, instant, in-browser diff checker.
🔒 Compared locally in your browser.
How to use Text Diff Checker
- Paste the original text on the left.
- Paste the changed text on the right.
- Review the highlighted differences.
Frequently asked questions
How does it compare?
It uses a line-based longest-common-subsequence diff, marking lines as added, removed or unchanged.
Is there a size limit?
It works on large texts, limited only by your device's memory.
Is my text uploaded?
No, the comparison runs entirely in your browser.
Related developer tools
UUID Generator
Generate random v4 UUIDs (GUIDs) in bulk and copy them with one click. Free, instant and fully in-browser using the secure crypto API.
Base64 Encode / Decode
Encode text to Base64 or decode Base64 back to text instantly. Free, private, in-browser — supports full Unicode (UTF-8).
JSON Formatter & Validator
Format, beautify, minify and validate JSON instantly. Free, private, in-browser JSON formatter with clear error messages.
QR Code Generator
Generate a QR code from any text, link, email or phone number and download it as a PNG. Free, instant and fully in-browser.