I looked at URL shortener limits some time ago and found these approximate limits by trial-and-error:
* TinyURL 65,536 characters and probably more, but requests timed out; there isn’t an explicit limit apparently
* Bit.ly 2000 characters.
* Is.Gd 2000 characters.
* Twurl.nl 255 characters.
This was 2.5 years ago, not sure how much of these have changed (other than bit.ly, which the linked article confirms is 2048, probably the same as when I tested it).
* TinyURL 65,536 characters and probably more, but requests timed out; there isn’t an explicit limit apparently
* Bit.ly 2000 characters.
* Is.Gd 2000 characters.
* Twurl.nl 255 characters.
This was 2.5 years ago, not sure how much of these have changed (other than bit.ly, which the linked article confirms is 2048, probably the same as when I tested it).
http://softwareas.com/the-url-shortener-as-a-cloud-database