Anki - AnkiWeb (cloud storage) file size limits - official and actual

creation-date:: 2023-07-28

Over the years I have enjoyed a larger Anki storage limit than officially advertised. So, I have no complaint. I just need to avoid the trigger of whole-collection upload as much as possible, because it really is a pain in the neck.

Official limit: 250MB


Collections on AnkiWeb are limited to a compressed size of 100MB, and an uncompressed size of 250MB. This includes the text on your cards and the scheduling information, but does not include sounds/images, as they are stored separately.

Most users will never reach the limit. 25,000 average-sized cards and several years of review history will take up about 25MB, so to hit the limit you usually need to either be copying large amounts of text into each card, or filling your collection with hundreds of thousands of new cards that you aren't actually studying.

At the moment there are no limits on the size of your media, although the size of individual media files is limited to 100MB.

As the usage of Anki and AnkiWeb increases, at some point a pricing system may be introduced where basic, low-capacity accounts are free and heavier users can pay more for more space.

If you have hit the collection size limit, you will see messages about the collection being in an inconsistent state when you do a one way upload to AnkiWeb. It is not possible to increase the limit, because such large collections slow down AnkiWeb for other users. If you have imported a dictionary's worth of content, you will need to move some unused cards to a separate deck, export the deck, and then delete the deck from your collection. After doing so, Tools>Check Database can be used to free up space that was taken by the deleted cards.

Two different actual limits from experience

Limit in a forced whole-collection upload

The actual limit is about 315MB (314,572,800 bytes, as shown), higher than the posted 250MB.

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Higher limit in a normal incremental sync

The limit for incremental sync is even greater. I've had AnkiWeb accept my collection size up to 480MB. It kept growing larger and larger over time. Caveat: if somehow whole-collection upload is triggered, it'll enforce the 315MB limit again. I would have to jump through some hoofs to slim down then add incrementally.

New limit: 518MB:


(Update 2023-08-28) New record set in incremental sync: 687MB, with the latest re-notetyped of MoedTw

What forces whole-collection upload?

Any change of note type locally, even for just one card, will force such an upload.

Hack: How to avoid a whole-collection upload

Export the deck to a new profile, change the note type there, and import back to main profile. As long as there is no "note type change" in the main profile, there's no trigger.

Pushing the limit

(Update 2023-07-28) After I pulled the hack to restore Anki sync to its glory of 1.2 million records, I thought, why not see if I can add another important source of glossary: The official Chinese dictionary by Taiwan's Ministry of Education. So I did, and Anki gladly synced it to cloud. I now have 1.4 million records:

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With a collection size of 651MB (way over the official limit of 250MB or full-sync limit of 315MB).

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So glad to have this latest addition. I just looked up this Chinese idiom I just heard: 觥籌交錯. I could only think of wine cups. Now I know 酒籌 (chips used for tallying in a drinking game) is a thing.