Viewport Resizer: Ultimate Device Emulator & Website Testing Tool

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4.2 (

285 ratings

)

Extension Developer Tools 80,000 users

65 support issues

ARslan Ahmad

Jul 21, 2025

Not working

I had just installed extension and trying to open it by clicking on icon. It just show 'on' on icon but no popup opens or not tab change or new tab change. Initializing extension is making issue.If there are some other setups to follow just after downloading it, mention them into description as well. So that everyone knows how to use it.

Elvie Perez

May 29, 2025

facebook.com

recovery

Kimdavid

Jan 18, 2025

mobile phone

How can i get it

Sergio Vazquez II

Dec 1, 2022

Viewport Resizer - Custom Size BUG

There is a BUG in Viewport Resizer that consistently RESETS the custom viewport size ANY time you navigate. This is NOT the expected functionality, and does NOT happen when viewing ANY of the other sizes.

https://imgur.com/a/93cxmLc

Edward Cox

Jul 13, 2022

Unable to use with Shopify store

Access denied: Cross-domain security error
Is this something that I need to take up with Shopify or is there a way to tell Responsive Design Tool that it's safe?
Thank you

alhusayn Polakweg

Feb 17, 2022

Not showing on a specific site

Hi the resizer wont show on my site shop.alhusayn.nlDo you know why this is not working.

ZestCitron

Jan 31, 2022

Can't use it anymore

Everything was working fine but now I just have a white page when I click on the extension. I'm on macOS Monterey (Apple M1) and Chrome is up to date.

Edward Cox

Dec 6, 2021

Does not support Shopify pages

Access denied: Cross-domain security error
every single time. How frustrating.

Edward

Mohamed Alkhalifa

Jun 13, 2021

Mac Chrome

Hello! Your extension looks amazing! But I was unable to use it. Nothing happens when I click the extension icon on Google Chrome (Mac).

Whats weird is that when I tried to create a custom extension on your website, the dropdown was visible and functional. But when i go back to another window and click the extension button, again nothing happens.

Silver75_Z93

Jun 8, 2021

Changeable presets!

Would be so nice for testing other devices that aren't in the current list. Great extension btw, it's the only one I found that can mimic viewports bigger than the current resolution, which is pretty cool.