Image Occlusion Enhanced is the classic Anki add-on for masking labels by hand, one image at a time. StudyPDF reads your own slides and PDFs, masks the labels on every diagram for you, exports to Anki's native Image Occlusion, and builds flashcards, quizzes, and exams from the same upload.
Choose StudyPDF if
You want labels masked automatically from your own slides or PDF
You want cards that work in a stock Anki, with no add-on to install or maintain
You want occlusion plus flashcards, quizzes, and exams from one upload
You study on your phone and want everything in one synced deck
What StudyPDF doesn’t do
Replace hand-drawing. If you want to place every mask yourself with pixel control on one image, the add-on gives that. StudyPDF auto-masks and lets you adjust.
Run as a local, offline Anki add-on. StudyPDF is an app (iPhone, iPad, Android and web) that generates the deck, which you then study offline in Anki.
Choose Image Occlusion Enhanced if
You want to place every mask by hand with pixel precision
You prefer a free, offline tool that runs inside Anki
You already have decks built on the Image Occlusion Enhanced note type
Where Image Occlusion Enhanced is strong
No upload needed, you work straight from an image already on your computer.
How they compare.
Feature
StudyPDF
Image Occlusion Enhanced
Making the cards
Detects and masks labels for you
YesStudyPDF masks every label automatically
NoYou draw each mask by hand
Works from your whole PDF or slides
YesReads the file, finds the diagrams
NoOne image you load at a time
Precise hand-drawn masks
PartlyAuto masks, you can adjust them
YesFull manual control over placement
In Anki
Exports native Anki Image Occlusion
YesStock Anki note type, no add-on
PartlyIts own IO-Enhanced note type via the add-on
Works without installing an add-on
YesNothing to install in Anki
NoNeeds the add-on to make and edit cards
Survives Anki updates
YesBuilt-in note type since Anki 23.10
PartlyAdd-on can break when Anki updates
Beyond occlusion
Flashcards, quizzes, exams from the same file
YesOne upload, the whole study set
NoOcclusion cards only
Answers cited to your material
YesEvery answer shows the page
NoNot an answer tool
Tracks what you're weak on
YesPer-concept mastery, what to study next
NoJust makes cards
Access and cost
Free to start
YesFree to start, about 4 materials a week
YesFree and open source
Runs fully offline
PartlyApp and web, study offline in Anki after export
YesRuns locally inside Anki
Imports YouTube and reads scans
YesVideo links, scans, and photos
NoOne image file only
Image Occlusion Enhanced is the classic Anki add-on by Glutanimate that lets you draw masks over the labels on an image by hand to make occlusion cards.
Is StudyPDF a good Image Occlusion Enhanced alternative?
Yes, if you want labels masked automatically from your own slides and PDFs instead of drawing every box by hand. StudyPDF exports to Anki's native Image Occlusion with no add-on, and the same upload also makes flashcards, quizzes, and exams. The add-on is the better pick if you want free, offline, pixel-precise manual masking inside Anki.
Do I still need the Image Occlusion Enhanced add-on?
Not for new cards. Anki has had image occlusion built in since version 23.10, and StudyPDF exports to that native note type, so you can make and edit cards in a stock Anki without the add-on. You only need it to keep editing older cards already built on its own note type.
What does Image Occlusion Enhanced do that StudyPDF doesn't?
It runs locally inside Anki, fully offline and free, and gives you pixel-precise manual control to place every mask exactly where you want. It also has hide-one and hide-all modes and a mature note type behind many community decks. StudyPDF auto-masks from your files instead of being a manual in-Anki editor.
Does StudyPDF make image occlusion automatically?
Yes. Upload a slide, scan, photo, or whole PDF and StudyPDF finds the labeled diagrams and masks each label for you, then you can adjust any mask. It exports to Anki's native Image Occlusion note type, so there is no add-on to install.
Start studying.
Upload your course and ask Bo anything. No card required.
