pdfNerd

Free PDF viewer with highlight, underline, text and pen annotation. Ctrl+S saves your changes back into the file itself.

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".