# Compare PDF > Highlight text differences between two PDFs. - Page: https://acepdfmd.com/tool/compare-pdf/ - Updated: 2026-09-13 - Runs at: https://acepdfmd.com (Uploaded files are deleted within 60 minutes. No signup for light use.) - Also in 29 languages: https://acepdfmd.com//tool/compare-pdf/ ## See exactly what changed between two versions of a PDF Contracts get redlined, reports get revised, and after the third round of edits it is hard to remember what actually moved. Compare PDF lines up two versions of a document and highlights the text that was added, removed, or changed between them, so you do not have to read both files line by line. You choose two PDFs, an original and a revised version, and the tool sends them over an encrypted connection to compare the text and mark the differences; both files are deleted within 60 minutes either way. There are no settings to configure, just pick the two files and read through the results. This tool focuses on text content, so it suits spotting wording and clause changes better than pixel level shifts in images or layout. If the two files differ mainly in scanned images rather than live text, the highlighted differences will be limited, since there is no text underneath a scan to compare. A very long PDF may take a little longer to compare than a short one. No sign-up is required for occasional use, and a short ad supports the free version. It works the same way on a laptop, a tablet, or a phone browser. ## How to use the Compare PDF tool 1. Add your PDF file: drag & drop or click to browse. 2. Make your changes in the editor, then download the result. ## Common questions ### Is Compare PDF free? Yes. Compare PDF is free for light use with no signup needed. Anonymous visitors get 10 free tasks per day, and creating a free account makes daily use unlimited. A paid Pro plan removes ads and raises file-size limits for heavier work. ### Is my file safe? Yes. Your file is sent over HTTPS, processed by self-hosted open-source software on our servers (no third-party AI or cloud APIs), and deleted within 60 minutes at the latest, usually right after your result is ready. ### What file formats does Compare PDF accept? Compare PDF accepts PDF files. Convert other formats to a supported one first; the related tools below can usually do it. ## Related tools - [Compare Markdown](https://acepdfmd.com/tool/markdown-compare/): Highlight line-by-line differences between two Markdown files. - [PDF to Text](https://acepdfmd.com/tool/pdf-to-text/): Extract plain, unformatted text from a PDF. - [PDF to Word](https://acepdfmd.com/tool/pdf-to-word/): Convert PDF into an editable DOCX. - [PDF Reader](https://acepdfmd.com/tool/pdf-reader/): Open and read a PDF page-by-page, right in the browser. - [Edit PDF Metadata](https://acepdfmd.com/tool/pdf-metadata/): View and change a PDF's title, author, subject & keywords. Read the guide: [Is It Safe to Upload a PDF Online? A Privacy Guide](https://acepdfmd.com/guides/privacy-guide/)