Low performance Ionic v4

My ionic-selectable component is with very low performance in comparison to ionic version 3 with de same code.

It’s taking a long time to load the list (about 200 items).




   ionic (Ionic CLI)             : 4.12.0 (C:\Users\S59\AppData\Roaming\npm\node_modules\ionic)
   Ionic Framework               : @ionic/angular 4.6.2
   @angular-devkit/build-angular : 0.13.8
   @angular-devkit/schematics    : 7.2.4
   @angular/cli                  : 7.3.8
   @ionic/angular-toolkit        : 1.5.1


   cordova (Cordova CLI) : 9.0.0 (cordova-lib@9.0.1)
   Cordova Platforms     : android 8.0.0
   Cordova Plugins       : cordova-plugin-ionic-keyboard 2.1.3, cordova-plugin-ionic-webview 3.1.2, (and 24 other plugins)


   Android SDK Tools : 26.1.1 (C:\Android\sdk)
   NodeJS            : v10.16.0 (C:\Program Files\nodejs\node.exe)
   npm               : 6.9.0
   OS                : Windows 10

Can you provide some Code, how you realized the ionic-selectable? Maybe a Screencast would be helpful too.


I’m using this component. just whit a static list whit 200 items. When I click on the component to choose any option, the screen freezes until the component is rendered. The more items, the more delay. I have another custom component that happens the same thing.

Which Version of the Plugin do you use? The Documentation says you need to use >=4.0.0-beta.19 for Ionic 4. It’s also marked as a beta and shouldn’t be used in productive Code.

I think it’s related to the Plugin and not to Ionic 4, so you should ask the Developer for maintenance of the Plugin for Ionic 4.


I’m using the version 4.1.1. But this freeze whe components is rendering happens in another page too. It’s stranger.

Maybe it’s related to the Ionic 3 Codebase? Did you migrated everything like it’s documented in the Migration Docs?

Ionic 4 has some breaking changes in case of usage of Angular Components, etc…


I did the migration steps, and refactored the broken code, but following the same run. Even though it seems like every app is kind of slow. :slightly_frowning_face:

In that link, there are three options provided under “how do I handle a large list of items”. Which are you using and how?

I’m was using infinite scroll, but now I tested the virtual scroll and now it works properly. Thanks @rapropos and @Unkn0wn0x for listening.