Studdlechevron_rightGuideschevron_rightPDF to flashcards
From a PDF to flashcards, without the mistakes.
Your lecture notes are a PDF and you want cards you can review. You can write them as you read, or let an AI tool draft them. Either way works, as long as you check the result against the page, and maths and physics PDFs are where checking matters most.
By Marton Roux, who builds Studdle · updated
In short
Upload the PDF to a tool that drafts cards, such as RemNote, Knowt or Gizmo, or write the cards yourself as you read. Either way, check every card against the page: AI tools misread formulas, symbols and scanned pages. Keep one fact per card.
Two ways to do it
Writing the cards yourself is slower, and it is also studying: to turn a paragraph into a question you have to understand what it says. Letting a tool draft them saves the typing, and moves the work to checking. For a dense maths or physics course, the best route is often both: let a tool draft, then rewrite what it got wrong.
By hand: the method
- Read the whole section before writing a card.You can’t tell what matters until you have seen where the section is going.
- List what you must be able to recall.Definitions, theorems with their conditions, the methods you are expected to use. Worked examples rarely need a card of their own.
- Write one card per fact, as a question.“What does Ohm’s law state?” beats “Ohm’s law”: a question makes you produce the answer, not just recognise it.
- Type formulas in LaTeX.An app that renders LaTeX shows the formula as it appears in your notes.
- Note the page on each card.When a card confuses you a month later, you can go straight back to the source.
The guide to maths flashcards with LaTeX covers the syntax and what to ask on a maths card.
Before you upload: prepare the PDF
- check_circleCheck that it has text. Try selecting a sentence. If you can’t, the PDF is a scan, and the tool will need text recognition to read it.
- check_circleUpload one chapter at a time. Smaller files give cards you can check in one sitting, and tools cap what they take: RemNote’s free plan takes files up to 8 MB, and Studdle will take up to 60 pages.
- check_circleLeave out what you won’t be asked. Title pages, exercise sheets you have already done, and long proofs your course doesn’t require.
- check_circleKeep the PDF your lecturer gave you. Your own notes copied into it are welcome; a different textbook’s notation is not.
With an AI tool
These tools state on their own pages that they make cards from a PDF or from notes. What each one includes for free differs a lot.
| What it takes | Free | LaTeX | |
|---|---|---|---|
| RemNote | Text, PDFs and slides | 5 AI cards (about 250 words) | Yes, as cloze cards |
| Knowt | Lecture videos, PDFs and notes | Basic plan; AI limits not stated | Not stated |
| Gizmo | PDFs | Not stated | Not stated |
| StudySmarter | Slides, notes and documents | Free sign-up | Not stated |
| Quizlet | Uploaded course notes | Not stated | Not stated |
| Studdle (ours) | A PDF of up to 60 pages, or a photo | 25 credits a week; a PDF costs 1.5 a page, minimum 3 · from early 2027 | Yes, inline and display |
Checked on each tool’s own page, or its App Store listing, on 13 October 2026. “Not stated” means the page doesn’t say.
What goes wrong with maths and physics PDFs
A tool reads the text it can extract from your PDF. On prose that works well. On maths it is where the mistakes hide.
- check_circleFormulas flattened into text. A fraction or a subscript can come out as a line of characters: x2 instead of x², an integral without its limits.
- check_circleA symbol swapped or dropped. A minus sign, a prime, a transpose. The card still reads well, and it is wrong.
- check_circleScanned pages. A scan is a picture. Without text recognition there is nothing to read, and with it handwriting is where symbols get misread.
- check_circleConditions left out. The card keeps the formula and drops “for an ohmic conductor” or “if f is continuous”.
- check_circleStatements instead of questions. A card that copies a sentence from the notes teaches you to recognise it, not to recall it.
An example: one page, one card
The page says three things: the law, its condition, and the unit of resistance. The card keeps the law with its condition, and asks one question. A second card could ask for the unit.
2.3Ohm’s law
For an ohmic conductor, the voltage across it is proportional to the current through it:
R is the resistance, in ohms (Ω).
How to check the cards
- Read each card against the page.Not from memory of the lecture: with the PDF open beside it.
- Check every formula symbol by symbol.Signs, indices, limits, and what each letter stands for.
- Turn statements into questions.If the front of the card is a sentence you could only nod at, rewrite it as something to answer.
- Delete duplicates and keep only what you need.Ten cards on one definition cost ten reviews a week.
- Keep a card only if you could answer it.If the answer surprises you, the card is wrong or you haven’t studied that part yet. Find out which.
From a PDF to a quiz
Some tools also turn a PDF or notes into a quiz: Quizlet says it makes practice tests from uploaded notes. The check is the same, with one more rule: each multiple-choice question needs exactly one right answer, and wrong answers that a half-prepared student would pick. A quiz whose wrong answers are absurd tests nothing.
Check every card against the page.
Your lecture PDF, as cards you check
Studdle launches in early 2027. Hand Pebble, its AI coach, a lecture PDF or a photo of your notes: he drafts typeset cards from what’s on the page, with the formulas in LaTeX. Nothing is saved until you’ve read it.
Common questions
Can AI make flashcards from a PDF?add
Yes. RemNote, Knowt, Gizmo and StudySmarter all say they do, and Studdle will too. None of them can promise every card is right, so read each one against the page before you keep it.
Can I turn a PDF into Anki cards?add
Anki’s own pages don’t mention importing a PDF. The reliable route is to write the cards in Anki as you read, with formulas between \( and \).
Does it work on scanned or handwritten notes?add
Some tools say so: Parkeur and Revizoo take photos of handwritten or printed pages, and PDFQuiz reads scanned documents with text recognition. Check formulas with extra care, because handwriting is where symbols get misread. Studdle will take a photo of your notes too.
How many cards should one page give?add
As many as the page has things you must recall. A dense page of definitions and theorems can give several; a page of worked example may give one, for the step you would get wrong.