Online Diff Checker - Compare Text Files & Find Differences
Compare two texts side by side or in unified view. Line-by-line add/remove highlighting with instant results — fully client-side.
Paste original and modified text into the two panels and see line-level differences instantly. Toggle between unified and side-by-side views. Additions are highlighted in green, deletions in red. Supports drag-and-drop file loading and clipboard pasting. Uses the standard Myers diff algorithm running entirely in your browser — your text never leaves your device. Great for code reviews, config diffs, API response comparison, and translation review.
How to use
- 1
Paste original text
Paste or type the original text into the left panel, or drag and drop a file.
- 2
Paste modified text
Paste the changed version into the right panel. The diff updates in real time.
- 3
Choose view mode
Use Unified view for a single scrollable diff, or Side-by-Side to see both versions next to each other.
- 4
Review and compare
Green lines are additions, red lines are deletions. Use the stats bar to see the change count at a glance.
FAQ
Q.Is the diff computed locally?
Yes. All diff computation runs in your browser using the Myers diff algorithm. No text is sent to any server.
Q.What diff algorithm is used?
The standard Myers diff algorithm (via the diff npm package), the same algorithm used by Git.
Q.Can I compare code files?
Yes, any plain text works — source code, configuration files, logs, JSON, XML, and more.
Q.Does it support file upload?
You can drag and drop text files onto either panel, or paste clipboard content directly.