Up to 100 at a time.
About rolling dice online
A physical die is fair because it is symmetrical: no face has any reason to come up more often than the others. A virtual one has to earn that fairness differently, by drawing from a source of randomness that has no pattern and then mapping the result onto the faces without favouring any of them.
The second half is where most online rollers go wrong. Taking a random number and reducing it with a remainder makes the low faces slightly more likely, because the range being reduced rarely divides evenly by the number of faces. This roller draws again whenever a value falls in the part of the range that would skew the result, so a d6 gives each face exactly one chance in six, and a d100 gives each of its hundred the same.
Where the randomness comes from
This tool runs entirely in your browser, using its built in cryptographic random number generator. Nothing you type is sent to us, nothing is stored, and each result is thrown away the moment you leave the page. Numbers are drawn without the rounding bias that the usual shortcut introduces, so every outcome is as likely as every other.
Because nothing is recorded, a result here proves nothing to anyone afterwards. If you need a drawing that other people have to accept, for a prize, a campaign or an audit, use Winner Picker, which publishes each result on a permanent link with a signed record anyone can check.