Diff / Compare
Find the differences. Like a very specific game of spot-the-difference.
What this does
diff library (same algorithm as git diff). Line, word, and character-level diffing. All client-side.
Paste two versions of something and see exactly what changed. Additions show up green, removals show up red. Unchanged lines sit there unbothered. The output is a unified diff view below the two inputs, showing everything in context.
Common use cases
Comparing API responses between versions. Hit the endpoint before and after a deploy, paste both responses, see exactly what changed in the payload.
Checking configs. Someone says they "didn't touch anything." Paste the before and after. The diff doesn't lie.
Reviewing edits to prose. Word diff mode highlights individual word changes within sentences, which is much better than line diff for documentation and content.
Verifying migrations. Paste the expected output and actual output. If the diff is empty, your migration worked.
Things to know
Three diff modes, each for different situations. Line diff compares line by line, same algorithm as git diff. Best for code and structured data. Word diff highlights individual word changes within lines, much better for prose. Character diff catches single-letter typos and transposed characters that word diff would swallow.
The Ignore Whitespace toggle strips trailing spaces, normalizes tabs vs. spaces, and collapses multiple spaces before comparing. Turn it on when comparing code that got reformatted. Whitespace differences are real, but rarely the ones you care about.
Pro tip: if your diff output is noisy, normalize the formatting first. Run both inputs through a JSON formatter or sort the lines before comparing. Diffing two unsorted lists produces chaos. Diffing two sorted lists shows you exactly what was added or removed.
Privacy
Your text stays in your browser. Nothing gets uploaded, nothing gets stored. Compare proprietary code, production configs, legal documents. We won't know, and that's the point.