The destination URL that you see on the Links page of your Bitly account may occasionally look different from the one that you originally shortened. The links are the same, even if they may look a little different.
There are two possible reasons for this.
Percent encoding and normalized URLs
Percent encoding is the term for when a browser or other application changes characters from a URL into a three-character series starting with a percent symbol. This often happens with punctuation — for example, an exclamation point (!) may be replaced by %21.
When you shorten a link that is percent-encoded, we normalize the URL. That means we replace things like %21 with their original character (in this case, an exclamation point!)
Though they look different, they're the same link.
In addition to normalizing URLs, our system simplifies URLs when necessary. For example, http://bitly.com//test has an extra forward slash (/). We would simplify that to http://bitly.com/test.
Just like a normalized URL, these are the same link even though they look a little different.