JS - one huge file or many small files?

Is there a good rule of thumb as to how big (in size) a JS file should be - that if it grows bigger than this it's good idea to split it into smaller files?

What is better to load one complete JavaScript file on all pages or separate files based on different pages?

It is best to keep separate files or include all files in one file Javascript? To avoid multiple server requests, it is better to group all your JavaScript files into only one. If you're using C#.Net + ASP.Net, you can bundle your files — it is a very good way to compress your scripts.

What is considered a large JavaScript file?

URLs contain JavaScript files of size over 25 KB. The figure of 25KB is relatively arbitrary – there is no hard and fast rule as to what constitutes an JavaScript file that is 'too large'.

The same size as any other languages (never more than a few hundred lines), and the concat and minify at runtime (using the Closure compiler or the Yahoo libs or whatnot) is what we do.