This page, based on code by Jan Moesen, measures your link speed.
Since the original code gave me results in the 75 MB/s range, whereas my provider's monthly bill stated 6 MB/s, I added more "randomness" in the test data, thus eliminating (or at least diminishing) the effect of data compression.
The modified test gave me more realistic results in the 4 MB/s range...
By default, your link speed is tested by measuring the time it takes to download 512 KB.
You can use a larger number of bytes for more accuracy by specifying the size of the download:
numKB may be any number from 512..16384.
This is not a script to benchmark or determine the execution speed of PHP scripts. If you're looking for one, check out the PEAR Benchmark package.
This script sends 16384 KB of HTML comments to your client. Both generating and parsing that HTML may add to the total transfer time, so don't take this as your raw download speed.
(Show this page's source code)
Transferring 16384 KB