Text Diff Checker

A variant of the Myers diff — the same algorithm Git and most diff tools implement. It finds the longest common subsequence between the two inputs in near-linear time and highlights everything else as added or deleted. For very long inputs (100 kB+), expect it to slow down.

This tool does a line-level text diff, which works on JSON but will flag reformatted-but-equivalent JSON as different. For true structural diff (order-independent, type-aware), use a dedicated JSON diff tool like json-diff or a VS Code extension; line diffing is coarser.

Line diff shows whole changed lines. Character diff highlights the specific characters within a line. Line diff reads faster for prose and code; character diff is better when the change is a typo or a single-word edit. This view defaults to line diff with inline character highlighting on changed lines.

No — the diff runs entirely in-browser. That matters when you're comparing unreleased code, customer data, or confidential documents. Both pastes are held only in the open tab and disappear on refresh.

Git diffs include context lines (the default 3 lines above and below each change) and use unified-diff format. This view is more visual — side-by-side with highlighted changes. They're equivalent information, just rendered for different audiences.