Progress® Telerik® UI for Blazor Feedback Portal
Back to Feed
Request a Feature Report a Bug
Unplanned
Last Updated: 07 Oct 2026 18:18 by Tom
Michael
Created on: 18 Jan 2023 11:44
Category: PDFViewer
Type: Feature Request
43
PDF Viewer virtualization
Please implement UI virtualization for the PDF Viewer, so that it can render large PDF files quickly. We are talking about documents with hundreds of pages and even more.
Duplicated Items
3 comments
Tom
Posted on: 07 Oct 2026 18:18

Hello! We have a production need for this in a .NET MAUI Blazor Hybrid app on iOS and Android (Telerik UI for Blazor 14.0.0).

Because the PDF Viewer renders every page canvas on load, memory grows with page count until the OS kills the WebView. This means that the component cannot even be used to view something as simple as an employee handbook on mobile (and is just way inefficient on web).

For example, opening a 40-page text-only PDF (file size 390 KB) on an iPhone 13 crashes the WebView immediately (similar on a Galaxy A16). Note that lowering the RenderScale doesn't help - it's ignored on iOS and is only a floor on Android.

Since the PDF Viewer can't be used on mobile, we're now implementing our own custom PDF viewer (on top of PDF.js, just like yours) which defeats the whole point of using Telerik.

-Tom B.

ADMIN
Dimo
Posted on: 06 Jul 2026 05:41

Hi Nico,

We recently implemented the ability to set more flexible initial zoom levels, which was the most popular request for the PDF Viewer. This one is next in line, but we don't have a specific time frame yet. As soon as we plan the item, its status will change and you will receive a notification (if you are following the request).

Regards,
Dimo
Progress Telerik

Love the Telerik and Kendo UI products and believe more people should try them? Invite a fellow developer to become a Progress customer and each of you can get a $50 Amazon gift voucher.

Nico
Posted on: 03 Jul 2026 14:00
When will this be implemented?
I mean, the votes are pretty clear-cut.
Without this feature, memory spikes occur quickly with larger documents—causing Chrome to crash, for instance. A crash like that is really a no-go.
Create an account Log In
View
Type
Status
Category