Compare text · Free · In your browser

Before/After Diff Viewer

Paste two versions of a passage and see every insertion and deletion highlighted - then accept or reject each change individually.

A diff viewer compares two blocks of text and marks exactly what was added, removed, or changed between them.

No changes yet

Original

0 chars

Changed

0 chars

Paste your original and changed text above - or try an example:

0 of 0 changes reviewed

🔒 Runs entirely in your browser - open DevTools → Network and you'll see zero requests. Your text is never uploaded.

No upload No signup Works offline Network requests this session: 0

The short version

How to use it

Paste the original text on one side and the edited text on the other.
Review the highlighted additions and deletions.
Accept or reject changes and copy the merged result.

Private by design

There is no server and no upload. Everything runs with plain JavaScript on your device, so you can safely work with confidential or unpublished text. Open your browser's DevTools Network tab while you use it and you'll see zero requests - and it keeps working with your connection turned off.

Frequently asked questions

What is the difference between a word and character diff? +

A word diff highlights whole changed words, which is easier to read for prose. A character diff marks the exact letters that changed, which is useful for small edits like a single typo or punctuation fix.

Can I compare two versions of a document? +

Yes - paste the old version and the new version into the two panes. Every difference is highlighted so you can spot exactly what an edit or an AI rewrite changed.

Is my text uploaded or stored anywhere? +

No. Everything runs in your browser with plain JavaScript - your text is never uploaded, stored, or logged. Open your browser’s DevTools Network tab while you use it and you’ll see zero requests. The tool also works offline.

Margin note

Every tool here runs 100% in your browser. Open DevTools → Network while you use one and you'll see zero requests - your text never leaves your device. Prefer the deep dives? Read the writing on Penluma.