How to use the PDF Difference Highlighter
- Upload your file. Click “Choose file” or drag and drop your PDF files (you can add several and reorder them).
- Choose your options. Adjust the settings: Resolution. The defaults work well for most files.
- Process the file. Click “Highlight differences”. Processing happens right in your browser, so your file never leaves your device.
- Download the result. Preview or download the output. For multiple files use “Download all (ZIP)”.
About this tool
Merge, split, compress, convert, edit, sign, protect and analyse PDF files online.
Read the complete PDF Difference Highlighter guide
Frequently asked questions
Is the PDF Difference Highlighter free to use?
Yes. The PDF Difference Highlighter on Gemma-4 is 100% free with no sign-up, no limits and no watermark. An optional free account lets you save favourites.
Are my files safe?
Yes. This tool processes your file entirely inside your browser, so the file is never uploaded to any server.
Does it work on mobile phones?
Absolutely. The PDF Difference Highlighter is fully responsive and works on Android, iPhone, tablets and desktop browsers such as Chrome, Edge, Safari and Firefox.
Is there a file size limit?
You can upload files up to 50 MB each. For very large files, splitting them first gives faster results.
Who is the PDF Difference Highlighter useful for?
It is popular with students submitting assignments, office workers handling documents, government-form applicants — anyone who needs quick, reliable help with working with PDF documents quickly and securely.