The quota depends on percentage of the available space (and maybe also the total capacity), rather than the amount. If you currently have 1 GB available, you cannot exceed 300 MB (I am just throwing numbers here, I do not know the exact percentage).

And 300 MB is shared by all of the storage, not just your origin or just Indexed DB, as far as I know.

Yes, I have seen some speculations on these numbers. The most popular, I guess, is that storage is only 6% of available free space. However, in the test case, I'm just inserting a few records that will take less than 1Mb of free space whilst there is 1Gb available. I have a dozen of users facing the issue and their available free space varies from 1G to 2Gb (and 1 unconfirmed report when there is 20Gb). In MS Edge and Firefox, it is just working as expected. So when it comes to explaining what causes the issue I'm getting lost in guesses, since there is no proper Chrome's documentation regarding this behavior.

For local testing, if you go to DevTools > Application > Clear Storage you'll see the usage per type and the overall quota for your origin.

These should be roughly the same numbers returned via navigator.storage.estimate() - in your app you can check that and see if the space available for these users coincides with the errors you're seeing.

Usually, there are 80 B displayed in the Dev tools interface (sometimes numbers differ but they are always equal (used == quota).

navigator.storage.estimate() always show usage = 0 and quota = 0

even though I have 1.5 Gb of free space.
see attached screenshot

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	chrome_indexeddb_issue.PNG 63.1 KB View Download

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Try going to be chrome://histograms/ and searching on Quota.GlobalTemporaryPoolSize - this tells you how much space (in MB) Chrome has calculated it should allow all origins to share.

FYI, the code for calculations and constants are here: https://cs.chromium.org/chromium/src/storage/browser/quota/quota_settings.cc?sq=package:chromium&dr&l=54

There are lots of heuristics, but if you're under 10% and especially under 1% free, Chrome is going to restrict its pool size to avoid bricking the device (some OSs perform poorly when disk space is exhausted)

As explained in #7, we don't want to cause the free disk space to go too low, to avoid killing the OS. FWIW, I've broken my own Windows, Mac and Linux installs before (to the point where I had to boot off of a different disk and delete things) by accidentally eating up all available space, so this is a real problem.

If the problem is reducing customer support, I suggest trying to display a notification that asks the users to free up more space, without going into specifics.

I'm closing this bug, as we're not going to change out quota implementation to be more aggressive in low disk space situations. philipwalton@: please feel free to reopen and take over if you'd like to help with documenting our behavior here!

Ok, I understand. I will add an extended logging to my app and try to catch the case when a user has about 20Gb of free space available. If I will be able to reproduce it I will re-open the issue.

I'm facing the same issue and it is quite annoying because end users of my application do not consider 1.5GB of free disk space as low. I have to listen complains and show special chrome-specific notifications. In my case, this issue results in potential loss of data. In average application requires just 3MB of disk space so it is a shame to crash when there are >=1 GB of disk space available. I would be grateful if you provided at least some mechanism to resolve the issue.

By the way, while investigating the issue I've found out that once disk space reaches some limit (~1.6GB) then quota instantly drops to zero (from 50+MB) and does not allow to write even 1KB of data. I think, whatever heuristics are used it is not an expected behavior.