Steps to reproduce
The attached web page contains code to demonstrate the problem. At start up, a single
Uint8Array is allocated and kept in a global variable. The
run function repeatedly creates a
Blob from this byte array, and immediately calls
Blob.close (or the prefixed
Blob.msClose) to release the created blob. The
run function can be triggered manually with the “Run now” button, or can be run periodically with the “Run every 5 seconds” checkbox.
- Take a heap snapshot after the page loads using the F12 tools
- Inspect the page’s current memory usage
- Check the “Run every 5 seconds” checkbox to start running the test periodically
- Let the test run 10 times
- Uncheck the checkbox to stop the test
- Take another heap snap shot
- Inspect the page’s current memory usage again
- The page’s memory usage after the experiment is roughly equal to the memory usage before the experiment
- The page’s memory usage after the experiment is much larger than before the experiment
See the attached screenshot for a more detailed overview of the memory usage over time. Edge is used as baseline for the comparison, as it does not appear to have this problem. IE11 is on the left, Edge is on the right.
- Both browsers start at roughly equal memory usage: 46 MB for IE11, 47 MB for Edge
- During the experiment, IE11’s memory usage keeps increasing over time, peaking at ~247 MB near the end. On the other hand, Edge’s memory usage never exceeds ~120 MB.
- After the experiment, Edge’s memory usage falls back to 47 MB - indicating that all memory from the blobs created during the test was properly released. IE11’s memory usage remains at 138 MB - indicating that not all memory was released.
Windows 10 Pro 64-bit version 10586.218
Internet Explorer version 11.212.10586.0 - Update 11.0.30
Edge version 25.10586.0.0
Comments and activity
Thank you for providing your feedback on IE11.
We are not accepting feedback on Internet Explorer through this portal any longer (unless security related). We welcome any feedback you have on Microsoft Edge using this website. This item will be closed as By Design since IE feature bugs are not being worked unless security related.
All the best,
The MS Edge Team
- Microsoft Edge Team
Changed Status to “By design”
Thanks for the quick response.
If I understand correctly, Microsoft will only fix security-related bugs for Internet Explorer 11?
Does this also apply to Windows 7, 8 and 8.1 where there is no Microsoft Edge? This leak occurs on all platforms with IE11, it’s not specific to Windows 10. And as much as I would like to, I cannot tell my company’s customers that they have to use a different browser.
I guess this FAQ entry answers my question: security updates only. Very unfortunate, since this issue has a serious impact on our product.
Yes, that is correct. Sorry for the delay and apologies for the inconvenience this causes to your development efforts.
MS Edge Team