How to take notes on a PDF: annotate it, or study beside it

There are two ways to take notes on a PDF. You can annotate the file itself, highlighting and adding comments in the margin with a free reader like Adobe Acrobat Reader, Preview on a Mac or Microsoft Edge. Or you can keep the PDF open beside a separate page of notes, with each note linked back to the page it came from. Annotating is quicker for marking up a reading. Separate notes are better for studying, because you can write them from memory, rearrange them and test yourself on them. This guide covers both, the free tools for each, a method for study notes on a PDF, and how to do it on a Bord board.

How to make notes on a PDF for free

You probably already have a tool that can do it.

• Adobe Acrobat Reader (Windows, Mac, phones): the free reader lets you highlight text and add sticky-note comments. Open the comment tools, select text to highlight, or click to drop a note.
• Preview (Mac): open the PDF, show the Markup toolbar, and use highlight, text and note tools. Apple's support page walks through each one.
• Microsoft Edge (Windows, Mac): opens PDFs in the browser and lets you highlight, draw and add text.
• Markup (iPhone and iPad): open the PDF from Files and tap the pen icon to write on it, with an Apple Pencil on iPad.

These are fine for marking up a reading before a seminar. The notes stay inside the file, scattered across pages, and most of what you do in them is highlighting. Highlighting was rated as one of the least useful study techniques in Dunlosky and colleagues' review, because it does not make you recall or reorganise anything [1].

Annotate the PDF, or take notes beside it?

Annotate when you need the text itself: quoting a source in an essay, preparing for a seminar on a reading, or marking up a contract. The note belongs to that exact sentence.

Take notes beside it when you need to learn the content: a textbook chapter, lecture slides, a paper for an exam. Study notes need to be short, in your own words, and organised by idea rather than by page, and you need to be able to cover them and test yourself. A margin can do none of that. What you keep from annotation is the link back: every note should still say which page it came from, so you can check it later.

A method for study notes on a PDF

1. Put the PDF and your notes side by sideTwo windows, a split screen, or a board with the file in a preview panel. Switching tabs every minute breaks your reading.
2. Read one section, then hide itRead a heading's worth of the PDF. Then close or cover it and write the main ideas from memory, in your own words. Leave a question mark where you are unsure.
3. Check and linkOpen the PDF again, fill the gaps in a second colour, and put the page number on every note. If your tool supports links, link the note to the page so one click takes you back.
4. Turn notes into questionsRewrite each note as a question and a short answer. That is the version you revise from: cover the answers and test yourself, a few days later and again a week after.

Writing from memory in step two is retrieval practice, which the Dunlosky review rated as one of the two most useful techniques [1]. The same method for a printed textbook is in how to take notes from a textbook.

Taking notes on a PDF in Bord

Bord is a noteboard: one endless page for typed notes, sketches and files, with an AI that works on the same board. It does not annotate inside the PDF. It is built for the second way: the file beside your notes, with every note linked back.

1. Drop the PDF on a boardDrag the file onto the board. Bord reads it, indexes every page and finds the figures. This needs a free account. Free takes files up to 100 pages and 50 MB, with three files per board; Plus takes 500 pages and 250 MB, five per board; Pro and Max take 2,000 pages and 1 GB, ten per board.
2. Read it in the previewClick the file's card and the PDF opens in a panel beside the board. Your notes go on the board next to it, as typed text, sticky notes, boxes and arrows, or pen sketches.
3. Link notes to pagesSelect a note or a group of notes and add a link to the file, at a page. Clicking the link later opens the preview at that page, so any note can take you back to its source.
4. Use the AI where it helpsIf a page makes no sense, ask Ask to explain it; it writes the explanation on the board and links each claim to the page of your PDF it came from. Tutor can teach the file out loud, in order, drawing as it speaks. Then hide those and write your own notes.
5. Get tested on the fileAsk Quizbook for a quiz on the PDF. It marks your answers and links each miss to the page that covers it. Flashcards can make a deck from the file and bring cards back when they are due.

Your files are kept with your account until you remove them from your boards, and removing a file deletes it, its figures and its index. Bord does not use your boards to train AI models; the details are in the privacy policy. There is more on adding slides, textbooks and recordings on the your files page, and a walkthrough of the quiz step in how to turn a PDF into a quiz.

What is the best app for taking notes on a PDF?

It depends on which kind of notes you want.

• To mark up a reading: the free reader you already have. Acrobat Reader, Preview or Edge all do highlights and comments.
• To handwrite on PDFs on a tablet: a note-taking app built for that, such as GoodNotes, Notability or Flexcil, which put the PDF pages inside a notebook you can write on.
• To study from the PDF: something that keeps the file and your own notes side by side and helps you test yourself. That is where a board like Bord fits, with the AI there to explain and quiz you from the file.

Questions