Free Online PDF Highlighter

Upload a PDF and highlight it right in your browser — no install, no sign-up. Add notes, use multiple colors, and pick up where you left off. Create a free account to keep your PDF and highlights.

Drag & drop a PDF here

or click to choose a file (max 30 MB)

Your PDF is stored temporarily and deleted after 1 hour unless you create a free account to keep it.

No Install, No Sign-up

Drag in a PDF and start highlighting in seconds — right in your browser.

Highlight & Annotate

Mark up text with multiple colors and attach notes, just like on the web.

Keep It Forever

Create a free account and your PDF + highlights are saved and sync across devices.

How to Highlight a PDF Online

  1. 1

    Upload Your PDF

    Drag & drop a PDF onto the box above, or click to choose one from your device. Nothing to install.

  2. 2

    Highlight & Take Notes

    Select any text to highlight it in your chosen color, and add notes to organize your reading and research.

  3. 3

    Sign Up to Keep It

    Your PDF is temporary and deleted after 1 hour. Create a free account from the viewer to keep the PDF and every highlight — they move with you across devices.

Frequently Asked Questions

Do I need an account to highlight a PDF?
No. You can upload a PDF and start highlighting immediately, without an account or extension. If you want to keep the PDF and your highlights, create a free account from the viewer — everything you already marked is preserved.
What happens to my PDF after I upload it?
Your PDF is stored temporarily so you can read and highlight it, and it is automatically deleted after 1 hour unless you sign up. If you create a free account, the PDF becomes a private document in your library and is no longer deleted.
Is my PDF private?
Yes. Your PDF is reachable only through a private, unguessable link and is never listed publicly. Highlights you make before signing up are stored locally in your browser. When you create an account, your PDF and highlights become part of your private, synced library.
How large a PDF can I upload?
You can upload PDF files up to the per-file size limit shown on the upload box. For very large documents, the viewer renders pages as you scroll so it stays fast and responsive.
Can I highlight PDFs on the web too?
Yes — with the Web Highlights browser extension you can highlight PDFs you open on the web, plus any webpage, and keep everything in one place.
View all frequently asked questions →