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Highlight Local PDF Files in Chrome ​

Web Highlights works on PDFs stored on your computer, not just on PDFs hosted online. Open the file in Chrome and the extension turns it into a highlightable document — the same viewer, popup, and notes you use everywhere else. This guide is part of the PDF Highlighter docs.

Prerequisites

Before we begin, make sure you have our browser extension installed. You can install it here or get it from the Chrome Web Store, Firefox Add-ons, or Microsoft Edge Add-ons.

How to Open a Local PDF in Chrome ​

  1. Drag the PDF file into a Chrome tab, or
  2. Right-click the file → Open with → Google Chrome

Web Highlights detects the PDF and opens it in the built-in viewer. Select any text and the highlighter popup appears — see the quick start if you are new to PDF highlighting.

Highlighter popup on a PDF in Chrome

Enable "Allow Access to File URLs" ​

Chrome blocks extensions from local file:// URLs until you grant access once. If your PDF opens but Web Highlights does not appear — no popup, no sidebar — this toggle is almost always the reason:

  1. Paste chrome://extensions into the address bar and press Enter
  2. Find Web Highlights and click Details
  3. Turn on Allow access to file URLs
  4. Reload the tab with your PDF

One-time setup

You only need to enable this once per browser. The toggle lets Web Highlights open local PDFs in its viewer — it does not upload your files anywhere.

How Highlights on Local Files Sync ​

Your highlights are saved to your Web Highlights account and sync to the cloud like any other highlight. You can read them, tag them, and export them from the web app on any device.

The PDF file itself is not uploaded. That has one practical consequence:

  • To see your highlights on the document, open the same file from the same path on the same device. Chrome identifies local files by their file:// path, so a moved or renamed file looks like a new document.
  • On another device, your highlights are still available in the web app — they appear on the PDF itself only if the file exists at the same path there.

Already Annotated in Another App? ​

Local PDFs often already contain highlights from Adobe Acrobat, macOS Preview, or another editor. When Web Highlights finds them, it offers to bring them in — one click, notes and all. See Import PDF annotations.

Next Steps ​

Common Questions ​

Why don't I see the highlighter popup on my local PDF?

In nearly all cases the "Allow access to file URLs" permission is missing. Follow the steps above and reload the PDF tab.

Do local PDF highlights sync across devices?

Yes. The highlights sync through your account and are always visible in the web app. To see them on the document itself, the PDF must exist at the same path on that device — the file is not uploaded.

Can I share a local PDF with my highlights?

The most portable way is the Download button: it saves a copy that carries your highlights as ordinary PDF annotations — any PDF reader shows them, no extension needed. See Download or print a PDF with highlights.