How reliable is FF's (dev tools) screen size adjustment

...as a rule of thumb kinda of thing it is nice

[Storyman]

After installing Developer Tools extension for FF, I played around with the Screen Resize feature. It's rather basic in that you create different screen sizes (using options).

Using the resize feature causes the browser to change size. As far as I can tell it gives you an idea of what the various screen dimension will be on your layout.

I was wondering if anyone has done any 'real life' comparisions to actual monitor configurations. Does FF's browser resizing work as a way to judge the effect of different screen sizes on a layout?

In other words how useful of a tool is the resize tool?

[claus]

The thing you will be missing with the resize tool is relative sizes of fonts, images and so on.

You make the browser window smaller, but this is not the same as changing resolution, as with a smaller resolution (and same screen size in inches) the fonts and images will be bigger on the screen.

With the resize tool, the resolution of your monitor does not change, so you keep the same size fonts and so on.

[jamesa]

how useful of a tool is the resize tool?

Spot on IMO. It's all relative... if an image is 400 pixels wide it'll fill 50% of the width of a 800 pixel wide browser window, regardless of the screen resolution. If your screen is at 1024x768, browser window is at 800x600 and at the current text size you get 14 words on one line... change the screen resolution to 800x600 and you'll still get 14 words/line. At least in my tests.

Of course, you still have to account for taskbars and toolbars...