Diff Checker
Paste your original and changed text — see line-level differences with word-level highlights inside changed lines. Toggle ignore-whitespace and ignore-case, switch between side-by-side and unified views, copy the diff or download a .patch file.
Your texts are compared entirely in your browser. Nothing is uploaded.
How to use this diff checker
- Paste your original text on the left and the changed text on the right.
- Toggle 'Ignore whitespace' or 'Ignore case' if needed.
- Switch between side-by-side and unified views — changed words are highlighted within changed lines.
- Copy the diff or download as a .patch file for use with git apply.
Frequently asked questions
How is the diff computed?
Using the Myers diff algorithm — the same family of algorithms used by git diff and most code editors. It finds the shortest edit script between the two texts.
What is word-level diff?
When two lines are paired (one removed and one added), the tool runs a second diff at the word level so you see exactly which words changed inside the line — not just that the line is different.
Can I export the diff?
Yes. Copy the unified diff to clipboard, or download as a .patch file you can apply with git apply.
Why does the diff show whole lines as changed when I only edited one word?
Myers diff matches lines first, then runs word-level diff inside paired lines. If your edit also added whitespace (auto-indent, trailing spaces, line-ending change), the line counts as 'removed + added' rather than 'modified'. Toggle 'Ignore whitespace' to collapse those cases.