Possible memory leak causing massive RAM usage on Mac Safari

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  • Description of the issue: There appears to be some kind of memory leak when using Memrise on Safari. If I have Memrise open for a couple hours of studying, it starts to take up 2+ gigs of ram. The only way to fix it is to dump the cache using the developer tools menu and restart Safari.

  • Your device and browser details MacBook Pro 2017 13in 16gb RAM

  • Description of steps to reproduce the issue Study for an hour or so in Memrise and/or leave Memrise open as a tab for a few hours after studying doing a couple 100 word speed reviews.

  • Do you have any screenshots of the problem? Please upload them here. I just dumped the cache but I will follow up with screenshots. This popup comes up https://appletoolbox.com/webpage-using-significant-energy-in-safari-heres-what-you-should-know/ and when I go to activity monitor it shows Memrise using multiple gigs of RAM until I empty the cache and restart the browser, where it then hovers around 170-250mb until the process repeats.

Upon further examination it seems you need to leave the tab open on the page that appears right after you finish a learning session and won’t happen if you have it back on the course homepage or the statistics page which I left open all last night as an experiment.

@Mark_Boyd, I am attaching @MemriseSupport, otherwise they may not see this proplem.


Thanks, I just upgraded to Big Sur and it doesn’t seem to be happening now, I will keep a look out and see if it happens again!


Thanks for the report - I’ve raised this to the relevant team, who will have a look asap. If it keeps happening, please do let us know.



Thanks for spotting this, Mark!

We also have a new version of Speed Review available if you turn Memrise Labs on in https://app.memrise.com/settings/learning/. Let us know if that is any better.

If the new version is causing you issues, we’ll definitely get this fixed for you.

James on the Web Team


Thanks! I’ll empty my cache and try it out now, it just started happening again

Also just as an aside, how insane is it that the touchbar takes up nearly 1/16th of my ram jesus what a terrible design idea.

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Just used the new speed review and same problem still there, sorry!

Ive seen this happen with other websites since posting this - not sure its purely a Memrise problem or something with how Safari works or what, but Ill mark this as solved as it doesnt seem specifically to only happen with Memrise.

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