Unresolvable Collection Too Large Sync Error


Popup error:

Your collection file is too large to send to AnkiWeb. You can reduce its

size by removing any unwanted decks (optionally exporting them first), and

then using Check Database to shrink the file size down. (⁨485MB > 250MB⁩)

Steps I have taken:

  1. Deleted all unused media (that should be deleted when a deck is deleted)
  2. Emptied the trash
  3. Rebuilt the database (Check database)

Still can’t sync

  1. Delete decks
  2. repeat steps 1-3

Still can’t sync and the “(⁨485MB > 250MB⁩)” message is unchanged.

I don’t believe the message correctly indicates the cause of the problem, the data amounts don’t change.

Steps I took to create the problem in the first place:

  1. Modified previously installed shared deck - US Presidents(with pics)
  2. Renamed Front card to Ordinal->Name
  3. Created flip card Name->Ordinal
  4. Created cards Year->Name, Name->Year, Picture->Name
  5. Attempt to sync
  6. Popup message:

Your decks here and on AnkiWeb differ in such a way that they can’t be merged together, so it’s necessary to overwrite the decks on one side with the decks from the other.

If you choose download, Anki will fetch the collection from AnkiWeb, and any changes you have made on this device since the last sync will be lost.

If you choose upload, Anki will send this device’s data to AnkiWeb, and any changes that are waiting on AnkiWeb will be lost.

After all devices are in sync, future reviews and added cards can be merged automatically.

  1. Upload to AnkiWeb

The persistent error suggestions that either:

  • Too much data is being INCORRECTLY reported, causing a sync blocking exception
  • Hidden redundant data is being created after following the above steps, that cannot be purged.
  • A problem on the AnkiWeb side

The message is intending to convey “your collection is 485MB; it needs to be less than 250MB”.


dae, stating the obvious doesn’t contribute anything to the thread. But thank you for your comment.
In the end, I deleted all the decks, and then rather than reimporting the collection without change (which already didn’t work), I reinstalled all the decks one by one instead, and it uploaded. There is another issue there, and looking at how much of a mess the deletion logic is, being largely without cascading deletes, I suspect that my usage created a lot of unreported, unremovable, orphaned data that was blocking the upload, or that the database was building inconsistently. That’s my hypothesis.

@dae was probably in a bit in a hurry there, with the 2.1.50 Beta and lots of development tasks to do. Looking at how many support queries he answers each day, I think we can forgive him that oversight :grin:

Until Damien gets back to this, linking to some code examples of that messy deletion logic would help. If you got suggestions how to improve it, you can also open an issue or PR on GitHub.

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I’m new to this sorry. Thanks.
Regarding the deletion logic being without cascading deletes, I’m referring to all the manual steps needed (delete media, delete trash, rebuild database, manually clear down orphaned Note types), and with that being the case, and seeing the behaviour I’ve experienced re: the dataset size remaining unchanged for me even after deleting the decks that pushed it over the limit. This is a user report, not a developer report, hence the use of the word hypothesis :wink:

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Actually, now that I think about it, I was also getting another (completely false) warning message, on deleting a deck and then trying to re-import it, claiming that I had exceeded the card limit of >1,000,000 cards, which was completely false, and the import succeeded anyway…

As is stated in the link @dae has sent, media has nothing to do with it. A common cause for this error are notes with lots of websites copied into them.
“4. Delete decks” is a bit vague. Did you delete all of your decks? It might well be that a single deck is responsible for almost all of the 485MB, and the other decks only have a few KB each.

These are all very different routines and not usually used simultaneously, so it wouldn’t make sense to bundle them.
Delete media moves media to the trash bin, Delete trash empties the bin. This is an extremely widespread and user-friendly design pattern.
Check database can resolve some errors with decks, cards, notes, etc. It doesn’t handle media.
Orphaned notetypes have to be removed manually, because more often than not, the user wants to keep them for future use. Also, since you need a notetype to create notes, they need to to exist beforehand.


It was incorrectly reporting that I had over 1M cards, and that the data exceeded 485mb even after decks were deleted (LIFO) and database “checked”. Something is up.
Delete-of-media-wise, I still think cascading delete of deck associated data, is a clean and obvious win (associated Notes could be checkbox optional).
Anyway, not an issue for me now.