Ionic 2 very slow on Edge compared to Chrome/Safari/Firefox

Fixed Issue #11555978


Dirk G.
Apr 7, 2017
This issue is public.
Found in
  • Microsoft Edge
Found in build #
Fixed in build #
Reported by 11 people

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Steps to reproduce

Repro steps per Nolan


1. Navigate to

  1. Click the dots on the bottom to dismiss the tutorial

  2. Start recording

  3. Click on “Speakers”

  4. (Click back and forth between “Speakers” and “Schedule” as many times as you’d like to observe slowness)

  5. Stop recording



Original description


Running an Ionic 2 App in Edge is very slow compared to Chrome/Safari/Firefox… Same problem when build as a with Windows 10 UWP or Windows Phone 10 application. On a Lumia 650 it takes a few seconds for click events to be registered. Example site: Performance of my app on a Lumia 650: Clicking on Schedule and Speakers results in poor performance. The more list elements there are the worse it gets… Related issue with more informations:


Comments and activity

  • Changed Steps to Reproduce

  • In Addition to the original post. If you just compare the mobile experience. The app works fast and fluid on e.g. a android device. Even if i compare a low end android to my Lumia 950.

  • Microsoft Edge Team

    Changed Assigned To to “Steven K.”

  • even after upgrading to the new creators update(EdgeHTML 15.15063 ) I can still see slow performance on on Lumia 950.

  • So, Steven K, any update on this? Its been a while now and this is fairly important.

  • Microsoft Edge Team

    Changed Assigned To from “Steven K.” to “James M.”

  • Hi Ali,

    I apologize for the delay.  I have requested additional help on this issue.

    It is easiest for me personally to verify an issue on the desktop.  Would you say a valid test case/repro would be to compare the performance of the conference app running in Edge vs Chrome vs Safari?  I.e. it would be enough to show the issue?



  • Microsoft Edge Team

    Changed Assigned To from “James M.” to “Steven K.”

  • I was able to reproduce this using the demo app URL you sent me in a current public release and a recent dev build.

    It appears that this issue occurs when the Ionic 2 application/template is used.  There are a lot of DOM changes going on by switching from the “Schedule” tab to the “Speaker” tab and as one user @tenglandct mentioned (last post of the first open issue below), the issue gets worse as the number of items increases.  We will investigate further.

    I think you should also continue to push for a resolution of the Ionic issues as well.  I have read those conversations and below is a list of what I found as related open issues for the framework:

    OPEN - “Windows phone performance issues”

    OPEN - “Ionic2 very slow on Windows Phone 10”

    OPEN - “Ionic 2 / Ionic 3 Apps Painly Slow on windows 10 UWP”

    OPEN - “Layout Thrashing has negative impact on Microsoft Edge performance”

    Appreciate the submission and pushing on this issue,


  • Microsoft Edge Team

    Changed Assigned To to “Steven K.”

    Changed Assigned To to “wwatri”

  • Note from the sidelines:

    Don’t expect any big effort on Ionic’s side before the release of Ionic v4. Ionic Angular v4 will switch to Web Components for all the Ionic components which totally changes the performance characteristics of Ionic apps. As this is quite a lot of work, they are fully focused on getting this out the door - and I assume with a focus on their main platforms iOS and Android for now. Let’s hope this has also positive effects on the Windows and Windows Phone performance.

    Can the edge team maybe give pointers what Ionic should look or work at if they decide to invest time here? I would think one of the problems is that in Chrome/Safari the performance is just ok, but Edge somehow not.

  • Microsoft Edge Team

    Changed Title from “Ionic 2 applications very slow on Edge, Windows 10 UWP and Windows Phone 10” to “Ionic 2 very slow on Edge compared to Chrome/Safari/Firefox”

    Changed Assigned To to “”

    Changed Assigned To from “” to “Kevin H.”

    Changed Status to “Confirmed”

    Changed Assigned To from “Kevin H.” to “Nolan L.”

    Changed Steps to Reproduce

    Changed Assigned To from “Nolan L.” to “Bogdan B.”

  • Jan: We’ve investigated this, and most of the issues come down to recalculation of styles. It looks like the DOM is being heavily reshuffled by Angular when e.g. clicking on “Speakers.” This leads to a lot of setAttribute calls which invoke layout/style recalc. You can see this in the Edge F12 tools if you open the Performance tab.

    We’ve confirmed this issue and are looking into a fix. In the short term, if Angular/Ionic wanted to improve this, it would probably come down to looking into the DOM-diffing algorithm and see if there are ways to reduce the setAttribute calls. Hope that helps!

  • Microsoft Edge Team

    Changed Status from “Confirmed” to “Fixed”

  • We’ve made improvements that will positively affect this scenario and generally every attribute heavy manipulations. I’ve tried the repro steps on the recent builds that have the changes and the experience is significantly improved - while I didn’t take the comparison traces between Edge and Chrome - perceptually the interactions are on par following the fix. Resolving as Fixed, since the targeted work improved the interactions and please let us know if you see further problems!

  • Awesome!

    When and what version of Edge will this be released with?

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