Your comments

I don't understand what the problem is...

Hi smedz28,

I'm sorry but it's not my fault. The extension uses standard Chrome APIs to re-size the window ( but Chrome sometimes fails to set those desired dimensions and there's nothing I can do about it except warning you that re-sizing failed.

You could enable the re-size tooltip to see the exact dimensions of the window & viewport like this:



Hi Linda,

Thank you for taking the time to make this short tutorial! You should receive an email with a license key that you can use to "upgrade" to Pro; it's the least I can do to show you my appreciation. :)

Just a small addition: the old version of the extension required the same permissions when installing it, which scared lots of people away. The new version doesn't require any kind of permission when installing and re-sizing just works. However, those permissions are still required by the re-size tooltip and there's no way around that, so people that need that feature will still have to grant them.

Here's a small F.A.Q. article I wrote a while back to answer people's concerns:

Best Regards,


Hi Scott,

This is not a bug. The 1024 x 768 built-in preset is intended to re-size the browser's viewport, not the window, to show a web page like it would display on a tablet. (The viewport is the area where a page is shown, excluding all the window borders and toolbars; this is meant for developers to test the responsiveness of the pages they are creating because, as the description of the extension says, this is primarily a developer's extension).

So, you asked for a viewport of 1024, your display scaling is set to 125% and your left and right window borders are 10 pixels each, so you have 1024 * 1.25 + 10 (left) + 10 (right) = 1300 pixels. Same thing goes for the height, except the address bar and the titlebar at the top of the window are 105 pixels so you have 768 * 1.25 + 105 (top) + 10 (bottom) = 1075.

Anyway, if you need the actual window, including borders & stuff to be 1024 x 768, you need to open the extension's settings, go to "presets" and add a new one or edit the existing one, making sure that the "Resize target" is set to "Window".

Best Regards,


If you ran them side by side for several months and you knew the Beta doesn't work for you, why didn't you say anything? I'm sorry, but that's the purpose of a Beta version: users try new features and they report bugs so they get fixed before the software gets released as stable. Since you didn't report anything, I just assumed everything is good...

Hey guys,

Version 2.6.0 (released yesterday) should have removed that error message. However, please note that it's not quite fixed and I can't really fix it because it's a Chrome issue. (Read bellow for details on why it "worked" in the old version. Short answer: it didn't)

More details for those interested:

The extension uses the method from the Chrome extensions API to try to update the window's width & height (this is the only way). Unfortunately, Chrome doesn't always set it correctly on a display scaling other than 100%. For example, on a scaling of 125%, even though I required a height of 667px, Chrome always set it to 668px. (I suspect this is due to some math rounding errors when Chrome calculates the window size it needs to draw depending on the display scaling)

Now, because people often complained about the previous version of the extension of being unreliable, in v2 I decided that, after re-sizing, I should check if the re-sized window was indeed set to the desired dimensions and, if not, revert it to the initial size and display that error message. Stupid me assumed that this would happen only when the width & height were too small or too big for the current window/display. As it turns out, it's Chrome's fault and I shall continue to be blamed for the "unreliability" of my extension (which is caused by the unreliability of Chrome, yet no one will know this...)

Best Regards,


Hey D.,

It was an intentional removal, however, on second thoughts (read: "under the pressure of an angry mob" :D) I decided to bring it back in the next few days. Please follow this thread to be notified when this feature is back:

Best Regards,