Input
Output
The Compare Text tool is a free online utility that finds the differences between two pieces of text. Paste your original on the left, the updated version on the right, and the changed lines are highlighted side by side — no setup, no account.
It uses a line-aware diff with synchronized scrolling, so matching lines stay aligned as you read. Inline word-level changes within a modified line are highlighted in color, and the gutter shows where additions, deletions, and edits occurred.
Everything runs in your browser — your text never leaves your computer. Use it for proofreading essays, reviewing code snippets, comparing config files, or auditing document revisions.
No. The diff runs entirely in your browser using JavaScript. Nothing is uploaded or saved on a server.
Performance depends on your device. Small and medium texts diff instantly. For very large texts (hundreds of KB or more) the diff may take a moment, but it still runs locally.
Line-by-line differences with inline word-level highlighting inside changed lines. Insertions, deletions, and modifications are color-coded.
Yes. Click Upload on either panel to load a plain-text file. The contents replace whatever is currently in that panel.
Once the page is loaded, the comparison runs locally — so an unstable connection doesn't affect it. The page itself still needs an initial load over the network.
Synchronized scrolling keeps matching lines aligned across both sides. Scroll either one and the other follows so changed regions stay easy to compare.