Diff Checker
Compare two texts side by side and see every addition, removal, and change highlighted.
Original
Modified
Nothing to compare yet
Paste the original and modified text above, or load the sample, to see every change highlighted.
All comparisons happen locally in your browser.
Diff Checker FAQ
- How are differences detected?
- Lines are matched with a shortest-edit-script (Myers) diff, then changed lines are compared word by word so small edits stand out.
- Can I ignore whitespace or letter case?
- Yes. Toggle ignore whitespace or ignore case to hide changes that only affect indentation, spacing or capitalisation.
- Can it compare large files?
- Yes. Unchanged lines at the start and end are skipped before diffing, so files with tens of thousands of lines compare quickly. If there are more than 3,000 line changes, the differing middle is shown as one replaced block.
- Does the side-by-side view work on phones?
- On screens narrower than 640px the diff switches to the unified view automatically, so lines stay readable; the side-by-side view returns on wider screens.
- Is the text I compare sent to a server?
- No. Both texts are compared locally in your browser.