Mozilla is about to make a built-in PDF Reader in Firefox, PDF.js even better with PDF Editing capability. What this means is users can able to annotate PDFs, they can write text, draw with ink, and further can save the PDF. The PDF editing feature is available in Firefox, here is how you can enable it right now.
Highlights:
- Firefox to get PDF editing feature with the ability to highlight text and add comments/annotations.
- Firefox PDF Viewer Offers new context menu options in editing mode
- No ETA or specific release not set for the feature.

Firefox PDF Viewer
Firefox’s built-in PDF Viewer displays most of the PDFs you encounter on the web inside the browser. Firefox opens PDF without saving it.
Firefox PDF Viewer can fill out forms, for instance, it can fill form fields such as text, checkboxes, and radio buttons.
Firefox supports XFA forms and generates a thumbnail view for PDFs
It also comes with fullscreen mode or presentation mode.
When you load a PDF in Firefox, to edit it, you need to download it and use third-party PDF Reader apps.
This can be avoided in upcoming releases when Mozilla enables PDF editing in Firefox:
How to enable PDF Editing mode in Firefox
- Open Firefox
- Visit about:config in the address bar
- Select the checkbox and click on “Accept the Risk and Continue”
- Search for pdfjs.annotationEditorMode and change its value from 1 to 0.
Note: You should be using Firefox 104 Nightly.
How to Edit PDFs in the Firefox browser
After completing the above steps,
Load a PDF document in the Firefox browser.
With editing mode enabled, you can see icons on the toolbar to add Free text annotation and free ink annotation to PDF documents.
The Text annotation mode allows adding text and lets you set Font Color and Font size.

Similarly, the ink mode option lets you draw over PDF document and set line color and thickness.

As we said above, Firefox provides the following right-click menu entries to edit a PDF:
- copy,
- paste,
- cut
- Select all
- Undo
- Redo.
These are the basic PDF editing features Firefox to get in a future release, it’s late but better late than never.
Final words:
Firefox PDF viewer to receive text writing, drawing and signatures feature as part of PDF Editing.
What’s your take on this? Which PDF feature you’re missing in Firefox and want Mozilla to add? Let us know in the comments below
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