Compare PDF

What it's for

See what changed in a document’s text between two versions of a PDF: the words that were edited, paragraphs that moved, and pages that were added or removed. Both files are read in your browser and go nowhere.

For example, when a supplier sends a revised contract as a new PDF, choose the old and the new and read only the places that differ.

How to use it

Choose the older PDF in the first box and the newer in the second, or drop each on the box it’s for. The result appears as soon as both are read.

Whole pages that read the same are skipped. Each changed page is listed with its changed paragraphs: removed ones in red, added ones in green, and within an edited paragraph the changed words marked. A paragraph that appears in one place in the first PDF and another in the second is marked “(moved)”. Pages that were only added or only removed are listed as such. Ignore capitals treats “Annex” and “ANNEX” as the same.

Example

Make a copy of a PDF’s source document, change one word in a paragraph and add a page at the end, save both as PDFs and compare them. You get “1 page changed, 1 page added”, with the old and new wording of the paragraph.

Good to know

This compares text only, not layout, fonts, images or drawings: a PDF whose only change is a logo or a colour shows no differences. Pages that are pictures of text, such as scans, have no text to compare; read them with the Image to Text (OCR) tool first, or compare their pages visually with the Image Compare tool (turn the pages into pictures with PDF Images). Paragraphs are found from spacing on the page, in the same way as PDF Text, so columns and tables can be split or merged in odd ways, and a change of layout can show as changes. A page with a few words in common is shown as removed and added rather than changed. PDFs with a password can’t be opened.