Free online diff tool
Compare two files online
Paste or drop two files and get a side-by-side diff instantly. The comparison runs entirely in your browser — your text never leaves the page.
Line-by-line diff
Additions, deletions, and modifications colored line-by-line with a merged inline or side-by-side layout.
Private by design
Nothing is uploaded. The diff engine runs client-side, so pasting company code is safe.
Works with any text
JSON, CSV, HTML, source code, or free-form prose — if it's text, you can diff it.
FAQ
Is my data uploaded when I compare files?
No. The diff runs entirely in your browser — nothing is uploaded or logged.
How large can the files be?
The comparer handles files up to several megabytes comfortably. Very large binary files aren't supported.
Do I need an account?
No account, no signup — open the page and paste your files.