Text Diff Checker
A diff tool that compares two texts and highlights added and removed lines and characters. Switch between side-by-side and unified views, show differences per line or per character, and ignore whitespace differences — all processed in your browser.
Enter text on both sides to see the differences here.
How to use
- Enter or paste the original text on the left and the changed text on the right. You can also load text files with "Open file" or by drag and drop.
- Differences are calculated as you type and shown in the result below, with added lines in green and removed lines in red.
- Switch the layout with "Side by side" / "Unified" and the highlight granularity with "Line" / "Character". You can also ignore whitespace differences or show only the lines around changes.
- Use "Copy to clipboard" to copy the differences in unified diff (patch) format.
About this tool
The text diff checker is useful for comparing drafts before and after edits, reviewing changes to config files, and investigating differences between API responses or logs. Just paste two texts to see what changed — no git or other tools required.
Differences are calculated line by line, and character-level differences are highlighted within changed lines. The character view shows exactly which characters changed in a line, making it easy to spot subtle edits such as a single digit or a full-width versus half-width character.
All comparison happens in your browser, and your text is never sent to a server. For very large texts or heavily changed content, the comparison stops after a set time and the number of displayed lines is capped to keep your browser responsive.
Frequently asked questions
What's the difference between "Line" and "Character"?
"Line" colors entire changed lines. "Character" additionally highlights, in a darker color, the specific characters that changed within those lines.
Do line ending differences (CRLF vs LF) show up as changes?
No. Line endings are normalized to LF before comparing, so files created on Windows and macOS/Linux show only real content differences.
Can I save the differences as a patch?
Yes. "Copy to clipboard" copies the differences in unified diff format (the same format as git diff). Paste it into a text editor and save it as a .diff or .patch file.
Is my text sent to a server?
No. All differences are calculated with JavaScript in your browser.