The default expiration time is 30 minutes, but you can extend it with a button on the website overview page.
Request a new screenshot of %(browser_name)s on %(platform_name)s?
Screenshot Factory "%(name)s"
Most of these are normal desktop machines with domestic broadband internet. Distributed community processing ensures O/S and browser diversity, but it makes quality assurance much harder.
If you find a problem, please report it to us using <a href="/contact/reportbug">this form</a>.
The best solution on Linux or Mac OS is to create a simple shell script with your desired options, make it executable (chmod a+x), put it somewhere on your PATH and then use the name of the shell script as the browser command.