Memory Leak: IE11 and MS Edge

Confirmed Issue #8992678 • Assigned to Paolo S.


Gyandeep S.
Sep 20, 2016
This issue is public.
Found in
  • Microsoft Edge
  • Internet Explorer
Reported by 9 people

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Steps to reproduce

Updated repro steps:

  1. Go to No in Edge/IE
  2. Open F12
  3. Open Task manager
  4. Watch the memory slowly go up over time.

Original repro steps:

Recently we started using babel and also babel polyfill for our project. While everything works great on chrome we started seeing some sort of memory leak on every refresh of the page. Now i have narrowed it down to babel-polyfill artifact. Babel polyfill is just an exmaple but IE has been an issue for a lot of other artifacts also.

System setup

  • OS - Windows 10
  • Browser - IE11 (11.103) and Fancy new IE Edge (38.14393.0.0)


  • babel-polyfill - 6.13.0
<!DOCTYPE html>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>JS Bin</title>
//<----- plz but babel-polfill's ./dist/polyfill.js code here ---!>
  }, 1000);

Note: Above page gets refreshed every 1 sec



Memory is constantly rising over time. I also did a test run for 10 mins, same result it was rising all the time.


  • Doesn’t happen in Chrome
  • Based on a experiment i did on a different project, it turns out any kind of circular reference leads to such kind of leaks in IE. I will experiment more to make sure this point holds true.


  • Is this a known issue?
  • Has anyone seen/experienced this?


  • I did the above run for 50mins on IE11 (win7) and the memory usage went from 45mb to 1.2 gb. It seems IE’s GC never kicks in?
  • I tried using the dev tool to even monitor a microsoft webpage even then the memory was constantly rising. Tried same results.
  • To be honest, i have been using chrome dev tools but IE or edge devtools are no good when it comes to memory stuff.


Please see other feedbacks in userfeedback VSO for feedbacks that are tracked by this work item.


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    Comments and activity

    • Microsoft Edge Team

      Changed Assigned To to “Rico M.”

      Changed Assigned To from “Rico M.” to “Riff J.”

      Changed Status to “Confirmed”

    • I can get the same memory leak without all scripts except.

      There are two possibilities: 1) what we see in Developer Toools is … the memory leak of Developer Tools 2) it is memory leak of setTimeout.

    • The memory leak can be observer without Developer Tools only in Task Manager (with the same HTML that contains only location.reload() ). The speed of memory leak depends on HTML size - you can add huge
      and them memory leak will grow very fast.

    • Microsoft Edge Team

      Changed Assigned To from “Riff J.” to “Nolan L.”

      Changed Steps to Reproduce

      Changed Assigned To from “Nolan L.” to “Mike J.”

    • I created a live repro here ( with extra divs to see the memory leak a bit faster.

      I can see the memory leak in both IE11 and Edge, on both standard Anniversary Update (aka Edge 14, 14393.693), and on an Insider build 14998.1000. However I only see it when the F12 tools have been opened. Note that even if you close F12, the leakiness persists until you fully close and re-open the browser.

      Gonna reassign this to F12 since it seems to be an F12 issue and not a core IE/Edge issue. Also modified the STR in this bug.

    • Microsoft Edge Team

      Changed Assigned To from “Mike J.” to “Paolo S.”

      Changed Steps to Reproduce

      Changed Assigned To from “Paolo S.” to “Mike J.”

      Changed Status from “Confirmed”

      Changed Assigned To from “Mike J.” to “Jordan B.”

      Changed Status to “Confirmed”

      Changed Assigned To to “Rico M.”

      Changed Assigned To from “Rico M.” to “Riff J.”

      Changed Assigned To from “Riff J.” to “Mike J.”

      Changed Assigned To from “Mike J.” to “Paolo S.”

      Changed Status from “Confirmed” to “In progress”

      Changed Status from “In progress” to “In code review”

      Changed Status from “In code review” to “Fixed, not yet flighted”

      Changed Steps to Reproduce

    • It is observable on Win7 IE11 too.
      Do you guys have any date when the fix is available for Win7?

    • Microsoft Edge Team

      Changed Assigned To to “Paolo S.”

      Changed Status from “Fixed, not yet flighted”

      Changed Status to “Confirmed”

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