Highlight PDF
EditDrag highlight boxes over any part of a PDF to mark important sections. Pick the colour and opacity — your highlights stay visible in every PDF reader.
How to use Highlight PDF
- Open this page in any modern web browser — no download or installation required.
- Click Add file or drag and drop your PDF onto the drop zone.
- Adjust the available settings to fit your needs.
- Click the action button and save the processed file — the result is ready instantly.
Files never leave your browser. No upload to any server.
Processing runs locally on your device. No queues, no waiting.
No signup, no watermarks, no limits. Use as many times as you like.
Why use Highlight PDF on PDF Modern?
PDF Modern’s highlight pdf tool processes your file entirely within your web browser using modern WebAssembly technology. Unlike traditional online PDF services that require uploading your documents to remote servers, your files never leave your device — ensuring complete privacy and security. Processing happens at the full speed of your CPU, not limited by upload or download bandwidth, so even large files are handled in seconds. There are no file-size restrictions, no daily usage caps, no watermarks on output, and no account creation needed. It is a fully free, open tool built for everyday document workflows at home, school or the office.
Frequently asked questions
Are my highlights visible everywhere?
Yes — highlights are flattened into the PDF as semi-transparent overlays that show in every reader.
Can I remove a highlight?
Hover any highlight in the editor and click × to delete it before saving.