Compare text and documents

Paste two texts, or choose two files, and see what changed, word by word. Word documents and PDFs are read on your device, not uploaded. A paragraph that moved shows as one move, with any words changed inside it, not as a deletion and an insertion. Free, with no account or limits.

Also: Word to Markdown · PDF to Markdown · Free online Markdown editor

How to compare two texts

  1. Paste the original text on the left, or the top on a phone.
  2. Paste the changed text on the right.
  3. Tap Compare. Step through the changes with the arrows at the top; close the comparison to change either text.

How to compare two Word documents

  1. Choose or drop the original .docx on the first side.
  2. Choose or drop the changed .docx on the second side.
  3. Tap Compare. Each change shows on the page as the document draws it, old beside new, with the changed words marked.

Questions

Is it free?

Yes. Rapier is free and open source, with no account, ads or tracking.

Are my files uploaded?

No. Text, Word documents and PDFs are compared on your device. It works offline once the page has loaded.

Can I compare Word documents?

Yes. Choose two .docx files. Each is read as its formatted text, pictures included, and the changes show on the page, old beside new.

Can I compare PDF files?

Yes, PDFs with text. The first time, Rapier downloads its free PDF reader once. A scanned PDF has no text to compare.

Does it show moved text?

Yes. A paragraph that moved shows as one move, with any words changed inside it.

Does it compare code?

Yes. Paste code, or choose two code files, and the changed lines show with the changed words marked.

Can I edit the result?

Yes. Open either side in Rapier, a free Markdown editor, and keep writing.

How it works

Rapier compares words, not just lines, then groups the edits into changes a person reads: a replaced word, an added sentence, a moved paragraph. It runs inside Rapier, one offline HTML file. Your browser reads each file; nothing is sent anywhere.

Use rapier-diff in your site or app

rapier-diff is the comparison engine inside Rapier: plain JavaScript, MIT licensed, no dependencies. Run npm install rapier-diff, then import {diff} from rapier-diff: diff(before, after) returns the exact edits and the changes they make.

rapier-diff on GitHub · rapier-diff on npm