I'm just making up a scenario, but let's say I have a 500MB file that I want to provide an html table for the client to view the data. Let's say there are two scenarios:
Ignoring things like pagination or virtual tables, I'm just concerned about "if the full dataset can fit in the user's available memory". Is this possible to detect in a browser (even with a user's confirmation). If so, how could this be done?
This answer has been answered about 6 years ago, and the question points to an answer from 10 years ago. I'm wondering what the current state is, as browsers have changed quite a bit since then and there's also webassembly and such.
Sort of.
As of this writing, there is a Device Memory specification under development. It specifies the navigator.deviceMemory
property to contain a rough order-of-magnitude estimate of total device memory in GiB; this API is only available to sites served over HTTPS. Both constraints are meant to mitigate the possibility of fingerprinting the client, especially by third parties. (The specification also defines a ‘client hint’ HTTP header, which allows checking available memory directly on the server side.)
However, the W3C Working Draft is dated September 2018, and while the Editor’s Draft is dated November 2020, the changes in that time span are limited to housekeeping and editorial fixups. So development on that front seems lukewarm at best. Also, it is currently only implemented in Chromium derivatives.
And remember: just because a client does have a certain amount of memory, it doesn’t mean it is available to you. Perhaps there are other purposes for which they want to use it. Knowing that a large amount of memory is present is not a permission to use it all up to the exclusion to everyone else. The best uses for this API are probably like the ones specified in the question: detecting whether the data we want to send might be too large for the client to handle.