Why it's a strong pick

This extension brings the PDF.js viewer to Chrome. It is open source under the Apache-2.0 license, and its code is public in the Mozilla pdf.js repository. The README names it the official extension for Chrome and says it is maintained by @Rob--W. It uses Manifest V3, Chrome's current extension format. The pdf.js project made a release on 29 August 2026, and the extension's folder in the repository changed on 9 September 2026. Those are repository dates, not store dates.

What it does

The manifest describes it this way: "Uses HTML5 to display PDF files directly in the browser." It opens PDFs from web addresses and, with Chrome's file-access setting turned on, from local files. It also has an options page and a managed-preferences schema for administrators.

Key features

PDF.js viewer. Open PDFs in a JavaScript viewer built with HTML5.
Web and local files. It handles http, https and file addresses. Local files need the file-access setting.
Viewer tools. The project's August 2026 release notes mention annotation editing, text selection and accessibility.
Options page. Change settings from the extension.
Admin settings. A managed-preferences schema is included.
Open source. The code is public under Apache-2.0.

Who it's for

This is for people who want an open-source, JavaScript-based viewer instead of Chrome's built-in one. If Chrome's viewer already does what you need, you may not need it. It is a viewer, not a tool for merging or splitting files.

What permissions does PDF Viewer ask for?

Its manifest asks for alarms, declarativeNetRequestWithHostAccess, webRequest, tabs, webNavigation and storage. It also asks for access to all sites. That list lets it catch PDF requests as you browse. Read the install prompt before you add it. Check that the access it asks for matches what you expect from a PDF tool.

Is it better than Chrome's built-in viewer?

We did not test the two against each other, so we cannot say. The extension overlaps with Chrome's own viewer. It is worth a try if you specifically want the behaviour of PDF.js. If you are happy with Chrome's viewer, leave it as it is.

Can it edit PDFs?

Only in a limited way that the project describes. The August 2026 release notes mention annotation editing. We found no mention of merging, splitting or converting files. If you need those jobs, look at the other tools in our PDF tools guide.

Does it open PDFs saved on my computer?

Yes, if you allow it. The manifest has a content script for file addresses. In Chrome you turn on file access for the extension on its details page. Without that setting, Chrome blocks extensions from local files. Turn it on only if you need it.

What does it do with my data?

We could not read the developer's privacy policy when we checked; read it before installing. The manifest shows it reads the PDF requests it handles and asks for access to all sites. Treat that as broad access to the pages you browse.

FAQ

Is it from Mozilla? The code lives in the Mozilla pdf.js repository, and the README calls it the official extension for Chrome.

Does it use Manifest V3? Yes. The manifest sets manifest_version to 3.

Is it open source? Yes, under the Apache-2.0 license.

Good to know

This is a viewer, so keep another tool for editing, merging or converting files. The extension's own version in the repository is a placeholder, so we do not give a store version or store update date. Test it on a couple of your usual PDFs, then decide whether to keep it.

Other pdf viewers & editors to compare

PDF Viewer by Mozilla PDF.js is one of 7 picks in our PDF Viewers & Editors guide:

Adobe Acrobat: Adobe's own Chrome extension. Free to view, comment, fill and sign. Convert and compress tools need a paid plan or trial.
Kami: A PDF and document annotation tool for classrooms. The Chrome extension is free, with basic markup tools and Google Classroom support. Some tools are paid.
Xodo: Online PDF tools from Xodo, part of Apryse. Edit, convert, compress, merge, redact and sign. Free use is limited per day.
iLovePDF: PDF tools from ILOVEPDF S.L., the company behind ilovepdf.com. Merge, split, compress, convert, protect, sign and OCR.
Enhanced PDF Viewer: A PDF reader for Chrome from PlugMonkey, built on the PDF.js engine. Keyboard shortcuts, presentation mode, text-to-speech and smart printing.
Smallpdf: A "Smallpdf Tools" tab for every PDF you open in Chrome. Compress, convert, merge, split, e-sign and AI summarize. The free tier has a daily task limit.