pd.am at a glance

pd.am is a service of Pixel Dreamer.

This URL shortening service was created to help you make the most of every last character in length-restricted messages such as found when microblogging (twitter) or text-messaging. It generates a case-sensitive URL — http://pd.am/ — followed by a short code or "key."

Through the use of case-sensitivity and the inclusion of the dash (-) symbol, the keys are generated from a 63-character set versus the more commonly found keys generated from the case-insensitive, strictly alphanumeric 31-character set. That means we can generate more than double the number of extra short keys than most other services out there.

In addition, we fully standardize all submitted URLs upon entry into the database, so pd.am is able to better search for and more effectively prevent duplicate entries, freeing up more of the tiniest urls for new entries.

Finally, since we always verify the existence of submitted resources, keys won't end up being wasted. pd.am has been designed to be as efficient as possible without restricting free and open use.

faq

How many n-character long URL keys can pd.am generate?

63 1-character URL keys
3969 2-character URL keys
250047 3-character URL keys
15752961 4-character URL keys
992,436,543 5-character URL keys
62,523,502,209 6-character URL keys

Based on the above figures we're guessing that we'll likely never make it to the 5- or 6-character long URL keys. Using only 6-character long keys we'd be able to index more than twice as many pages as currently exist on the entire internet.

Why are minified URLs case-sensitive?

Keeping our minified URLs case-sensitive nearly doubles the number of super short URLs we'll be able to generate. We're going for short here — if this is a deal buster for you there are plenty of case-insensitive shortners out there for you to pick from.

How are duplicates accounted for?

If the URL you're submitting was previously minified, you'll be presented with the original minified URL instead of having a new key created for the same destination. Upon storage in our database, URLs are standardized (scheme://user:pass@host:port/path?query). This standardization is what ensures we're able to find and prevent duplicates so effectively.

Can I minify the URL of a page that doesn't exist?

No. If the page isn't there, we won't index it.

Why have we bothered to create yet another URL shortener?

Of course, there are indeed dozens of other similar services out there, a couple producing URLs that are just as short as pd.am's. Unfortunately, the URLs generated by any such service will eventually grow in length.

For all intents and purposes, the keys generated by most URL shortening services will "max out" at a length of 5 characters. That may not sound like much, but for many people, those one or two extra characters can make a enough of a difference that they will move on to find another service capable of providing the 1-4 character URL key they demand. We're offering to be that newer, shorter service.

What also sets pd.am apart from the rest is our cross-referencing tool. We'll check the other most commonly used minifiers - bit.ly, is.gd & TinyURL to ensure that the minified url you're getting is as mini as absolutely possible.

Please note: As of 8/10/09 tr.im support has been removed.

app integration

Want to integrate pd.am with your application? Great! We've tried to make this as easy as possible.

A call to http://pd.am/?a=api&u=http://yourreallylongurl.com/ will return the minified result in plain text without any additional formatting — the perfect format for utilizing with your app. Below is a simple PHP function that takes a given URL and returns the minified result. Please note that this is just for demonstration purposes — in practice you should "make safe" & validate the supplied url before attempting to minify it.

            // provided with a valid url returns the minified result
            function minify($url) {
              $url = urlencode($url);
              $result = file_get_contents("http://pd.am/?a=api&u=".$url);
              return $result;
            }

We also offer a cross-referencing feature: simply append &full=1 to the end of your request URL (e.g. http://pd.am/?a=api&u=http://yourreallylongurl.com/&full=on) and we'll query all the most popular third-party URL shorteners for you and return whichever URL is shortest. You'll almost always find that a pd.am minified url is returned as it's usually the shortest, but using this feature ensures that you're always getting the shortest possible URL, even in the rare instance that it's being offered by a different service. Third-party URL shorteners supported by pd.am currently include bit.ly, is.gd & TinyURL. Support for tr.im was recently removed due to performance issues.

**8/10/09 - API UPDATE**

JSON formatted results are now available. Simply add &format=json to the end of your request URL (e.g. http://pd.am/?a=api&u=http://yourreallylong url.com/&format=json). Please help us to test this new feature and send any bugs to bug@pd.am. More documentation and code example to come soon. Thanks!