Free PDF viewer with highlight, underline, text and pen annotation. Ctrl+S saves your changes back into the file itself.
Users
93
+48 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
2
+1 in 30 days
Store rank
#87K
#73K among extensions
Version
1.0.0
updated 13 Jul 2026
Users
monthly, 3 months
Latest, 19 Oct 2026:93 usersMove the mouse over the chart for any month
Ratings count
monthly, 3 months
Latest, 19 Oct 2026:2 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About pdfNerd
pdfNerd replaces the browser's built-in PDF viewer with one you can actually mark up — and it saves your annotations back INTO the file itself. Press Ctrl+S: no more "paper(1).pdf" copies piling up in Downloads.
WHAT YOU CAN DO
• Highlight in any color — your own palette, any hex you like
• Underline and strikethrough — saved as real PDF annotations, visible in any PDF app
• Text notes — drop a typed note anywhere on the page
• Pen — draw freehand, with thickness and opacity sliders
• Save in place — Ctrl+S writes changes into the actual file (one permission dialog the first time ever, silent after)
• Recent PDFs — the toolbar icon lists PDFs you've opened; one click reopens them
READING-FIRST SHORTCUTS
Select text, press Ctrl+H, and the highlight lands while your cursor returns to the page — no switching into a "highlight mode" and back. All shortcuts are remappable in Options:
Highlight Ctrl+H · Underline Ctrl+U · Strikethrough Ctrl+Shift+U · Text box Ctrl+B · Pen Ctrl+D · Save Ctrl+S
(On macOS, use Cmd in place of Ctrl.)
REAL ANNOTATIONS, NOT PICTURES
Everything you add becomes a standard PDF annotation baked into the file on save. Reopen the file anywhere — Adobe, Preview, your phone — and your marks are there, still editable and deletable.
WHY THE ONE-TIME SAVE PROMPT
Browsers forbid any extension from silently overwriting files on disk — that's a browser security rule, not a pdfNerd limitation. So you point at the file once and approve; every save after that is silent. On Chrome/Edge 122+ you can choose "Allow on every visit" and never see a prompt again.
PRIVATE BY DESIGN
Zero network calls except fetching the PDF you open. No accounts, no ads, no analytics, no tracking — your PDFs and your edits never leave your computer.
Full policy: https://github.com/Khayrulbuet13/PdfNerd/blob/main/PRIVACY.md
FREE AND OPEN SOURCE
Apache 2.0, built on Mozilla's pdf.js: https://github.com/Khayrulbuet13/PdfNerd
Tip: to annotate local files, open the extension's details page and enable "Allow access to file URLs".