PDF Reader & Annotator
Highlight, note and sign · nothing uploaded
Read and mark up PDFs on any device
Open a PDF to read it, highlight the parts that matter in five colours, write a note beside each one, draw, type, pin notes, fill in forms and sign. Everything is saved in this browser as you go, and Save PDF gives you a copy whose marks show up in Preview, Acrobat, Zotero and your browser’s own PDF viewer.
Key facts
- The PDF is opened and drawn in your browser by pdf.js; the file is never uploaded.
How this works: Method,
How this works
Method
The PDF is drawn in your browser by pdf.js, the open-source engine inside Firefox. Your marks are kept on this device as you make them, and Save PDF writes them into a new copy as standard PDF annotations (Highlight, Ink, FreeText, Stamp and Text), which other PDF readers show.
Changes
- First published.
How to highlight and annotate a PDF5 steps, all on your device
- Open a PDF. Choose a file, drop it on the page or paste it. It opens in this browser; nothing is uploaded. The sample paper is there to try things on.
- Highlight and add notes. Select text and pick a colour from the bar that appears. Tap a highlight, or its card in the Annotations panel, to write a note beside it.
- Draw, type, pin notes and sign. Use the toolbar to draw with a pen or marker, type text onto the page, pin a note anywhere, add an image or place your signature.
- Fill in forms. Click into a form’s fields and type. Your answers are kept with the document on this device.
- Save a copy. Save PDF downloads a new file with your marks as standard PDF annotations, so Preview, Acrobat, Zotero and browsers show them. The original file is never changed.
What is kept, and whereThis device only, until you save or share a copy
- Your marks (highlights, notes, drawings, text, images, signatures) are saved in this browser as you make them, tied to the file by a fingerprint of its contents, so the same PDF finds them again.
- The files you open stay in this browser too (the last 20), so Recent reopens them where you left off. They are never uploaded, and backups leave them out because they can be large.
- Form answers are kept with their document on this device and only go into a backup when you include sensitive data on the backup page.
- Annotations already in a file (from Preview, Acrobat or another app) are shown and listed. Edit or remove those in the app that made them; this reader keeps them as they are.
Need to merge, split, rotate or convert pages instead? The PDF tools do that, also without uploading.
Frequently Asked Questions
Is my PDF uploaded anywhere?
No. The file is read from your device into this browser tab and drawn there by pdf.js, the open-source PDF engine inside Firefox. It is never sent to a server: there isn’t one involved.
Will my highlights and notes show in other PDF apps?
Yes. Save PDF writes your marks as standard PDF annotations: highlights as Highlight annotations with your note as their comment, drawings as Ink, typed text as FreeText, images and signatures as Stamps and pinned notes as Text notes. Preview on a Mac, Adobe Acrobat, Zotero and the PDF viewers in Chrome, Edge and Firefox all show them.
Where are my annotations kept, and can I lose them?
They are saved in this browser as you make them, so closing the tab or reloading loses nothing; the last 20 PDFs you opened reopen where you left them, from Recent. The original file is never changed. Your marks are included in the one-file backup and folder sync on the backup page (the PDF files are not, as they can be large), and opening the same file again on another device brings its marks back.
Does it work on a phone or tablet?
Yes, the same way as on a laptop. Long-press to select text, drag the handles, then tap a colour in the bar at the bottom of the screen. The tools sit in a bar within reach of your thumb, pinch zooms the page, and you can install the reader as an app from the page header.
Can I fill in and sign PDF forms?
Yes. Type into the form’s fields, tick its boxes, then draw, type or photograph your signature and place it on the page. Save PDF writes the answers and the signature into the copy. The signature is an image of your handwriting, not a certificate-based digital signature.
Can it open password-protected PDFs?
Yes. You are asked for the password when the file opens. It is used in this tab only and never stored, so it is asked for again next time.
Are there keyboard shortcuts?
Yes. On a computer press ? in the reader to see them all: V to select, H to highlight, D to draw, T for text, N for a note, Ctrl or ⌘ with F to find, with S to save a copy and with Z to undo, and J and K for the next and previous page.