How to highlight and annotate PDFs online — free

You want to do something simple: highlight a few lines, jot a note in the margin, come back to it later. Somehow that turns into creating an account, uploading a private document to a stranger's server, and watching a "Save" button quietly turn into "Upgrade to Pro."

ReadHere does it differently. The PDF opens in your browser and is rendered on your device. It isn't uploaded anywhere. You highlight, you note, you close the tab — and it's all still there next time, because it was saved locally the whole time.

Highlight and annotate a PDF in three steps

1. Open the reader — no account, no upload screen.
2. Drag your PDF in (EPUB works too, with the same tools).
3. Select any text to highlight it, then add a note if you want to say more.

The annotation tools you actually use

• Four highlight colors. Yellow, green, pink, and blue — enough to separate "important" from "disagree" from "look this up" without inventing a color system you'll forget.
• Notes attached to the text. Tie a comment to the exact passage, not a floating sticky that drifts out of place.
• One sidebar for everything. Every highlight and note in the book sits in a list you can scan and click to jump back to the page.
• A per-book journal. When a margin note isn't enough, each book has its own notebook for longer write-ups — a summary, an argument, an essay in progress.
• Search to find a word or phrase anywhere in the document.

The selectable text layer means highlights land on the actual words, so they stay put when you zoom or change the theme.

The same tools work on EPUB

This is the part other readers skip. You can highlight and annotate EPUBs the exact same way you do PDFs — same colors, same notes, same sidebar. Your textbook PDF and your novel EPUB live in one library and behave the same. No switching apps depending on the file type.

Why "no upload" matters

Contracts, medical forms, unpublished manuscripts, a draft of your thesis — plenty of PDFs aren't things you'd hand to a random web service. Because ReadHere renders the file in your browser, the document never leaves your machine on the free tier. Nothing to leak, nothing cached on someone else's server.