4 Best Study Apps for Taking PDF Notes

The best study app for PDF notes depends on what you need to do after opening the file. Choose Goodnotes when handwriting and stylus markup matter most. Choose RemNote for detailed flashcards and scheduled review. Choose NotebookLM when you need source-grounded questions across several PDFs. Choose BrainDen when you want each PDF to become a structured note inside a connected study library.

Do not compare these apps only by asking whether they can import a PDF. A useful study workflow also lets you verify the note against the source, add your own thinking, find the material later, and practise without keeping the answer visible.

The four PDF study apps at a glance

BrainDen: Best for connected PDF notes and several practice formats. It keeps the source available for highlights, comments, and checks. Free to start; Pro starts at $19.99 monthly or $99.99 yearly.
Goodnotes: Best for handwriting and stylus-first PDF annotation. It supports writing, highlighting, search, organization, Study Sets, and AI tools. Free limited plan; Essential costs $11.99 yearly.
RemNote: Best for PDF annotation with detailed spaced repetition. It connects highlights, notes, flashcards, quizzes, and image occlusion. Free includes three annotated PDFs; Pro costs $8 monthly when billed yearly.
NotebookLM: Best for questions and synthesis across several PDFs. It uses PDFs for cited chat and generated study artifacts. Standard is free; Google AI plans start at $9.99 monthly in the US.

Prices, limits, and platform features can change. Confirm the purchase screen for your country and device before paying.

How we compared PDF study apps

We reviewed current official product, help, and pricing pages. We then compared each app against five questions:

Can you return from a note or answer to the relevant PDF passage?
Can you add highlights, comments, handwriting, or your own explanation?
Can you turn the material into questions or another retrieval task?
Can you organize many PDFs across courses and topics?
Does the free or paid plan support the workflow you need?

The third question matters because highlighting does not test recall by itself. Carnegie Mellon University's retrieval-practice guide describes recall followed by feedback as an active learning method. A PDF app should help you move from reading to an honest attempt, then back to the source for correction.

1. BrainDen: best for a connected PDF study library

BrainDen fits students who want a PDF to remain part of a larger course system. Import a permitted reading, textbook chapter, handout, or slide deck. BrainDen creates an editable structured note while keeping the PDF available for checking details, highlighting passages, and adding comments.

The same note can support flashcards, quizzes, mind maps, and Explain It Back practice. This makes the handoff from reading to retrieval simple. The source remains available when a card removes an important qualification or a generated explanation misreads a table.

Organization is also part of the workflow. Nested folders can reflect semesters, courses, modules, and topics. Links and backlinks can connect a PDF note to a lecture or tutorial in another folder. The linked-notes feature is useful when one reading explains evidence that appears in several classes.

Best for: students who want structured PDF notes, source checks, connected organization, and several active-recall formats in one learning-first system.

Limitation: BrainDen is not an ink-first digital notebook. Goodnotes is a better fit when freehand writing, drawing, and detailed stylus markup are the main tasks. Free BrainDen accounts currently support an initial three notes. Standard Pro pricing is $19.99 monthly, $49.99 for six months, or $99.99 yearly. Storefront prices and offers can vary.

BrainDen's current PDF-to-study-notes workflow documents the source, highlight, comment, verification, and practice steps.

2. Goodnotes: best for handwriting on PDFs

Goodnotes is the clearest choice here for students who treat an iPad or tablet like digital paper. Its official PDF annotation page documents handwriting, typed notes, highlights, comments, search, organization, and PDF sharing. It also works on iOS, iPadOS, macOS, Android, Windows, and the web, although some tools remain stronger on Apple devices.

This workflow suits lecture slides, worksheets, diagrams, and readings where spatial placement matters. You can write beside a chart, circle a label, or add an explanation in the margin. Search can include handwriting, typed text, and PDF content.

Goodnotes also offers Study Sets and AI features. However, its strongest reason to choose it is still the flexible writing surface. A student who wants a close digital replacement for paper may prefer it over an app that first converts the PDF into a structured note.

Best for: stylus users who want natural handwriting, visual markup, searchable PDFs, and notebooks across devices.

Limitation: a well-marked PDF can still become passive storage. You must deliberately create questions, hide the answer, and review errors. Students who want built-in spaced-repetition control may prefer RemNote.

The official Goodnotes pricing page lists a free plan with three files and a 5 MB import limit. Essential costs $11.99 yearly, and Pro costs $35.99 yearly. Expanded AI access is a separate $9.99 monthly AI Pass.

3. RemNote: best for PDF flashcards and scheduled review

RemNote connects PDF reading directly to a detailed flashcard system. Its current Reader documentation describes a split view with the document, annotation tools, notes, and flashcards. Students can highlight text, annotate the file, create cards from passages, and keep the card connected to its source.

RemNote is especially strong when material must remain retrievable for months. Its spaced-repetition queue schedules cards from past performance. Image occlusion also helps with labelled diagrams, anatomy, maps, and other visual material.

The app can generate flashcards, quizzes, summaries, and guided study from a PDF. These AI tools use credits, so compare the plan limits with the number and length of documents you expect to study.

Best for: students who want PDF annotation, permanent notes, detailed card creation, and scheduled spaced repetition in one knowledge base.

Limitation: RemNote has more structure and controls to learn than a simple PDF reader. Test the editor, card model, and review queue with one course before moving a full library.

RemNote's official pricing page lists unlimited notes and flashcards on Free, with three annotated PDFs. Pro costs $8 monthly when billed as $96 yearly. Pro with AI costs $18 monthly when billed as $216 yearly.

4. NotebookLM: best for questions across several PDFs

NotebookLM is different from the other three. Google presents it as a source-grounded research assistant, not a handwriting-first PDF annotator. Upload one or more PDFs, select the sources for a question, and inspect inline citations that lead back to the relevant source passage.

This is useful when a task depends on comparison. A seminar student can ask where three papers agree, which methods differ, or which source supports a claim. NotebookLM can also create study guides, flashcards, quizzes, mind maps, reports, and audio or video overviews from the selected sources.

Google's current source guide says the free tier accepts up to 50 sources per notebook. Each uploaded source can contain up to 500,000 words or 200 MB. Copy-protected files and poor scans can still fail.

Best for: students who need cited questions, summaries, and synthesis across a defined PDF source set.

Limitation: NotebookLM does not replace detailed handwriting or manual PDF markup. Each notebook is also independent, so it is less suited to a linked note library that grows across courses. Check cited passages because a citation does not guarantee that the answer preserves every qualification.

NotebookLM Standard is free. Google's upgrade table lists higher limits through Google AI plans. Current US Google One pricing lists Google AI Plus at $9.99 monthly and Google AI Pro at $19.99 monthly. Those plans also include storage and other Google services.

Which PDF study app should you choose?

Choose BrainDen when you want a connected path from PDF to structured note, course organization, and several practice formats.

Choose Goodnotes when you mainly handwrite, draw, or mark lecture slides with a stylus.

Choose RemNote when the PDF must feed a detailed flashcard collection with scheduled review.

Choose NotebookLM when you need to question and compare several PDFs with links back to source passages.

You may not need one app for every task. A student could annotate a diagram in Goodnotes and keep long-term cards in RemNote. Another could compare papers in NotebookLM, then move only verified conclusions into a connected study library. If you use two apps, define the handoff and avoid maintaining two complete copies of every note.

Test one difficult PDF before paying

Use the same real document in your two strongest candidates. Choose a PDF with headings, a diagram or table, and at least one point you do not understand.

Then complete this test:

Import the PDF and find a specific passage.
Add one annotation in your own words.
Create five questions that require recall.
Answer them without viewing the source.
Open the source passage that corrects one weak answer.
File the PDF under its course and topic.
Reopen the material on the device you use away from your desk.

Keep the app that makes the complete loop clear. Import speed matters less than whether you can verify, retrieve, correct, and find the material again.

For a practical method that works in any app, read how to study a PDF with active recall. When you want the source, structured note, and recall tools to stay connected, turn a PDF into study notes with BrainDen. The shared BrainDen block keeps Web, iPhone & iPad, and Android choices visible.