How to resize and lock Firefox browser windows for specific sizes?

Question

How would I re-size and lock Firefox browser windows for specific sizes?

For example, my resolution is higher but I want to fix the width to 768px and lock it.

Solution 1

Firesizer allows you to resize the window to specific dimensions.

Firesizer provides a menu and status bar to resize the window dimensions to a specific size. Unlike other similar extensions, this one sets the size of the entire window, not just the HTML area, which better reflects the environment that end users will be using.

Solution 2

I've used Sizer for Windows: http://www.brianapps.net/sizer/

From the web site:

Sizer is a freeware utility that allows you to resize any window to an exact, predefined size. This is extremely useful when designing web pages, as it allows you to see how the page will look when viewed at a smaller size. The utility is also handy when compiling screen-shots for documentation, using Sizer allows you to easily maintain the same window size across screen grabs.

Comments

[T.G]

Thanks. I know many resizer add-ons but I also want to lock the size

[T.G]

I know about it and many more but I'm looking for a option to lock the resizable browser window too

[soandos]

Whilst this may theoretically answer the question, it would be preferable to include the essential parts of the answer here, and provide the link for reference.

[Robert]

there was a command to input in the URL input box, but I can't recall what it was. There you were able to set the firefox window size in pixels