Paste text above and hit Compare (or just type — it updates live).
Compare two text files without installing anything: open or drop a file onto each pane below. The diff runs entirely in your browser — your files never leave your machine. The sample shows two saved versions of the same notes file.
Click open file… above either pane (or drag a file straight onto it), load the second file into the other pane, and the differences appear instantly — changed lines marked, with the exact changed words highlighted inside each line. It works for any plain-text file: notes, code, configs, exports, logs, HTML, Markdown. No install, no account, no size form to fill in.
This page is static. Reading the files, computing the diff (Myers line diff with word-level refinement) and rendering the result all happen as plain JavaScript in your browser — there is no server to upload to. That matters when the files are contracts, configs with credentials, or anything else you wouldn't paste into a random website.
It reads files as UTF-8 text — so a .docx, .xlsx or PDF won't work by opening the file directly (those are binary containers; copy the text out and paste it instead). Very large files work, but the browser does all the work, so a 100 MB log will take a moment. And it compares content, not file metadata like timestamps or permissions.
Ignore whitespace hides indentation-only churn. Collapse unchanged keeps long files readable by folding identical regions. Copy patch exports the result as a standard unified diff (diff -u format), and Share link packs both texts into a URL that never touches a server — handy for sending a colleague the exact comparison. Comparing JSON? Use the JSON diff to normalize formatting and key order first.