APKG - Anki Flashcard Deck File Format

What is an APKG file?

A file with .apkg extension is a deck of flashcards generated to be used in Anki software application which is a flashcard-based learning program. It contains HTML text to be loaded and displayed in Anki application and can additionally have images and sounds for visual and audible learning. Anki allows users to create their own Anki flashcard decks as well as import other user’s flashcard decks.

APKG File Format

Anki card decks are created from templates that are written in HTML, a famous and common language for creating web pages. The styling of deck cards is done using CSS which is the language used for styling web pages. The styling includes modifications to:

• font-family - The name of the font to be used on the card.
• font-size - The size of the font in pixels.
• text-align - Defines whether the text should be aligned in the centre, left, or right.
• color - Defines the colour of the text which can be simple colour names such as “blue”, “red”, etc. or HTML colour codes.
• background-color - Defines the background colour of the card

The styling information is shared among all cards, affecting all cards when a change is made. The following example will use a yellow background on all cards except the first one:

.card { background-color: yellow; } .card1 { background-color: blue; }

Images resizing in an Anki card can be controlled as follow.

img { max-width: none; max-height: none; }

Embedding Javascript in Anki cards

It is possible to embed Javascript in an Anki card using the card templates. However, due to the advanced level of Javascript, its support is not provided. Moreover, rendering devices may show the implementation affects of Javascript in the card differently, resulting in the need of testing the implementation on all devices. Certain Javascript features such as window.alert, making it difficult to debug the Javascript code that you have written.

How to Open APKG Files on Mobile or Desktop Devices

An .apkg file is an Anki flashcard deck used for spaced repetition learning. It contains cards, images, audio, and formatting used in the Anki app — popular among students, language learners, and professionals.

How to Open APKG Files on Mobile

1. Using AnkiMobile (iOS)

• Download AnkiMobile Flashcards from the App Store (paid app).
• Open the app → Tap the gear icon → Choose “Import File” and locate your .apkg file.

2. Using AnkiDroid (Android)

• Download AnkiDroid from the Play Store (free).
• Place the .apkg file in the /AnkiDroid folder using a file manager.
• Open AnkiDroid → Tap the three dots → “Import.”

How to Open APKG Files on Desktop

1. Install Anki (Windows, macOS, Linux)

• Download Anki from the official website.
• Open the app → Go to File → Import → Choose your .apkg file.
• Your flashcards will be added and ready to use.

Key Characteristics of the APKG File Format

Characteristic	Description
File Extension	.apkg
Proprietary yet Open Structure	While the format is specific to Anki, its internal components (ZIP, SQLite, plain text/HTML) are open standards, making it possible for developers to inspect and interact with the data.
Not a “Live” Sync File	An APKG is a static export/import package. Continuous synchronization between devices is handled by AnkiWeb, not by repeatedly transferring APKG files.
Read-Only Upon Import	When an APKG is imported into an Anki profile, the data is merged into the user’s local collection. Subsequent reviews and edits affect the local database, not the original APKG file.
Media-Inclusive	Its self-contained nature is a key advantage—no separate media folder is required, preventing the common issue of “missing image” errors in shared decks.
Version-Sensitive	APKGs exported from newer versions of Anki may not be compatible with older versions of the software, due to updates in the database schema.

FAQ

Q1: Can I open an APKG file without Anki software?

A: Not directly for study. You can extract its contents as a ZIP archive, but to view and review the flashcards as intended, you need Anki or a compatible app.

Q2: Is an APKG file the same as the decks on AnkiWeb?

A: AnkiWeb hosts decks in a similar format for syncing, but the APKG is the offline file package used for manual sharing and backup.

Q3: How do I edit a deck I received as an APKG file?

A: Import the APKG into your Anki desktop app. The deck will appear in your collection, where you can freely edit cards, add notes, or change options.

Q4: Why is my shared APKG file so large?

A: Large file size is almost always due to embedded high-resolution images or audio files within the deck. The creator can optimize media before exporting to reduce size.

Q5: Can I convert an APKG file to PDF or Quizlet?

A: There is no direct conversion. You must first import it into Anki, then use add-ons or manual copying to transfer the content to other platforms, which may lose scheduling data.

References

• Anki Documentation