Compare versions

Upload an original and a revised PDF to see exactly what changed — added text is highlighted, removed text is struck through. Everything runs in your browser.

Original (v1)

Revised (v2)

Compare PDF versions (redline) — FAQ

How do I compare two PDF versions?

Upload the original (v1) and the revised (v2) PDF, then click Compare versions. DockDocs lines up the text and shows a single marked-up view — added text is highlighted in green, removed text is struck through in red, like track changes.

Are my files uploaded anywhere?

No. This is a client-side tool: the text is extracted and compared entirely in your browser, so your files never leave your device. Nothing is sent to a server.

Does it catch reworded sentences?

It compares sentence by sentence, so it marks which sentences were added and which were removed. A small reword shows up as one deletion plus one addition rather than a word-level change inside the sentence.

What does it actually compare — does it check formatting or images?

Only the extracted text. Fonts, layout, colors, images and tables aren't part of the comparison, and scanned PDFs with no real text layer won't produce useful results. If it reports no textual changes, the wording is identical even if the look changed.

How large can the documents be?

The whole comparison runs in your browser, so it's tuned for documents up to a few thousand sentences (it caps at 2,500 sentences per file). Very long contracts or books may be truncated or run slowly.

Is it free?

Yes — comparing versions is completely free, with no sign-up and no limit on the number of comparisons.