Compare two texts
Free side-by-side text diff. Paste two versions — code, prose, JSON, contract clauses, anything — and see what changed: red strikethrough on the original, green on the modified. Choose line, word or character granularity, and switch between side-by-side, unified (GitHub PR style) or inline view. Useful for: reviewing a contract revision before signing, spotting a sneaky license change in a third-party file, sanity-checking a copy-paste edit, comparing two JSON API responses to find an unexpected field, or generating a clean patch to share in chat. The same diff algorithm git itself uses, running locally so the texts never leave the page.
How to use
Original on the left, modified on the right.
Side-by-side for review, unified for sharing, inline for prose.
Red — original (deleted), green + new (added), gray = unchanged.
Ignore whitespace if formatting is noise; ignore case if it does not matter.
Diff two pieces of text or code with line, word or character granularity — in the browser
What you can do
Typical uses
- Spot what changed between two versions of a config file before deploying.
- Review a paragraph rewrite with word-level granularity to see exactly which words moved.
- Compare two JSON responses to find an unexpected field difference.
- Sanity-check a copy-paste edit against the original before committing.
- Generate a clean unified diff to share in chat or a code review.
Why this one
Most online diffs stop at line-level — when a single word changes inside a long line, you still have to eyeball the whole line to find it. We re-run the diff inside each changed line so word- and character-level edits are highlighted precisely. Especially useful for prose, legal text, and JSON where a single value buried in a long object is what matters.
Common questions
Why does comparing two big files get slow?
Because finding the smallest set of changes between two texts costs work that grows with the product of their lengths in the worst case, not with their sum. Two files that share most of their content compare quickly whatever their size, because the algorithm can match long stretches and skip them. Two files that share little — a rewritten document, a reformatted codebase — are the expensive case, and that is where a long wait comes from. Two things help directly: switch the granularity from character to line, which cuts the number of items being compared by an order of magnitude, and turn on ignore-whitespace if the difference you care about is not the indentation.
Which diff algorithm?
The same Myers longest-common-subsequence family that git, GNU diff and most code review tools use — so output matches what reviewers see in a PR. For word and character granularity inside changed lines, the same algorithm runs again on the tokens of just that line.
Why does my code diff look wrong with "Ignore whitespace" off?
Tabs vs spaces, trailing whitespace and CRLF line endings count as real differences when "Ignore whitespace" is off. Toggle the option if you only care about content changes.
Can I copy the diff?
The unified view is plain text — select and copy. The side-by-side view is HTML; the cleanest export is to switch to unified.
We can! Just send us a quick message with your idea. If you'd like to discuss it in detail, leave your email and we'll get back to you. You can stay anonymous.
