FAQ
This FAQ (Frequently Asked Questions) page gives answers to some common questions we get asked about cntp.me, as well as some that we never actually get asked but think people ought to be interested in!
Ways to use cntp.me
- Can I use cntp.me straight from my favourites list (bookmarklet)?
- Can I use cntp.me from my browser's search box?
- Is there a cntp.me plugin for my browser?
- Is there any other software I can use to create cntp.me links?
- Can I use cntp.me from the application or webpage I'm making?
- What is a QR code and why would I want to generate one?
About using cntp.me
- How can I view statistics on who has visited my shortened link?
- Why do I always get to a preview page when I visit a cntp.me shortened link?
- I turned off cntp.me's automatic link previews, how can I turn them back on?
- How can I get to the preview page to see link stats etc. without using automatic previews?
- How long do cntp.me links I create last?
- How long will my shortened URLs be?
- What custom URLs are allowed?
- Are cntp.me's shortened URLs unique?
- Can I delete the shortened URL I made or point it somewhere else?
- Can I shorten non-web URLs (e.g. ftp://)?
- What is the longest URL I can shorten with cntp.me?
- Does cntp.me require Flash/Javascript?
- What exactly do the "Lower case" and "Lower case pronounceable" radio buttons do?
Technology and architecture
Spam and abuse
- What action is cntp.me taking to prevent its shortened links being used for spam/abusive purposes?
- Why was my shortened link disabled?
Misc
- What's the deal with cntp.me and is.gd? Is there a difference between them?
- Can I/my company advertise on cntp.me?
- Does cntp.me use 301 redirects/does it give my links credit for SEO?
- Why does the counter on the front page sometimes jump around/increase a lot very quickly?
- What does cntp.me/is.gd stand for?
- Acknowledgements
Ways to use cntp.me
Yes you can. Just bookmark the following link: Shorten with cntp.me. When you click the link in your favourites list, cntp.me will provide a shortened link for the page you're on.
Please note that you need to bookmark this link (in most browsers either a right click menu option or done by dragging it to your bookmarks menu) - just clicking on it will try to shorten a link for the page you're on (in this case the is.gd FAQ) and throw an error because of that.
The bookmark requires Javascript to be enabled in your browser (usually on by default). You can safely ignore any security warnings that pop up when adding the bookmark - these are because the link contains Javascript code.
Yes. If you visit our homepage your browser should give you the option to add cntp.me as a search provider (often this is accessed from a dropdown menu near the search box). Obviously cntp.me isn't a search engine, but once you've done this if you put any URL into the search box with cntp.me selected, we'll shorten it for you.
There are 3rd party plugins available for most web browsers that support our service. See our software page for details.
Please check our software section for a list of 3rd party software that makes use of cntp.me.
In general yes. Our developer documentation has the information you need for this as well as some handy examples. Be sure you're aware of our API restrictions and limitations when deciding if cntp.me is suitable for your app.
A QR (Quick Response) code is a two dimensional barcode. When you generate one, it contains the cntp.me URL that you generated it for. If somebody scans it with a compatible device (such as an Android smartphone) they can go to your link. You could place the QR code in a magazine or on a business card. It's debateable whether this is more useful than just writing the shortened URL at the moment, but we think QR codes are cool technology and that more interesting uses for them will appear.
About using cntp.me
Visit the shortened link to get to its preview page. Once there use the link near the bottom of the page that says "I want to see statistics for this link".
Note that you can only view statistics for links that have stat logging switched on (accessed via the "further options" menu when you create them).
By default we send everyone who clicks on a cntp.me link to a preview page where they can check the link's destintion. This helps to prevent misuse of cntp.me (for example in spam emails) by making sure people who click our links, who may never have heard of cntp.me, are aware that they could be redirected anywhere and have the opportunity to check the destination. If you'd rather not see a preview page, visit our preview control page to turn it off.
Either clear the cookies stored in your browser or visit our preview control page and select the appropriate option.
Regardless of how you've set our automatic preview feature, you can always get to the preview page by adding a dash (-) to the end of the shortened URL e.g. https://cntp.me/example-. There's a link to view your URL's statistics on this preview page.
We don't remove shortened URLs as long as they're created in accordance with our terms & conditions. As such we expect them to last forever, excepting technical issues and other difficulties covered in our terms.
Our automatically generated URLs are typically 19 characters long (including the beginning https://) and will remain that long for the foreseeable future since we can store many billions of URLs of this length. The shortest custom URLs you can create are slightly shorter than this at 18 characters, but you can also make them considerably longer depending on your choice.
The custom part of the URL (everything after https://cntp.me/) must be between 5 and 30 characters long. Custom URLs are case sensitive and can only consist of upper and lower case letters, numbers and the underscore (_) symbol. Non-English characters aren't allowed in custom URLs (but you can shorten URLs containing them). We don't have any other restrictions and don't plan to appoint ourselves the moral guardians of the Internet, so things like rude words are allowed.
In most cases yes (shortening the same URL multiple times will get you the same shortened link back). This doesn't apply to custom shortened URLs (because we use the shortened URL you supply) or to URLs with stats enabled where we always generate a fresh link to make sure the stats we collect are specifically for you.
No. Our shortened links are permanent once created. The main reason that we don't offer this is that it could be abused (e.g. spammers could create innocuous links and later point them somewhere malicious).
Yes. cntp.me can shorten URLs that use most common protocols. This includes all on the IANA list of URI schemes except data: (as it was widely abused). We check schemes against a whitelist to cut down on junk submissions - if something you want to use isn't supported, get in touch and we'll consider adding it.
You can shorten URLs up to 5,000 characters long. This is an arbitrary limit we've imposed to prevent misuse rather than an architectural limitation. Hopefully we won't see web addresses this long any time soon!
Basic URL shortening is available without Javascript support, but more advanced features such as custom shortened URLs require it. Flash support is required to view graphs in the statistics pages for shortened URLs, but isn't used for anything else.
When a custom shortened URL has not been specified, we generate shortened URLs using a mixture of upper and lower case letters (the links are case sensitive) and numbers. The "Lower case" radio button restricts this to lower case letters and numbers. The "Lower case pronounceable" radio button restricts this further to lower case letters only and tries to generate something vaguely pronounceable using a basic algorithm which alternates vowels and consonants.
Technology and architecture
The software that helps make cntp.me possible includes: -
- nginx (web server)
- MySQL (relational database)
- mongoDB (document-oriented database)
- PHP (scripting language)
- APC (PHP cache)
See the acknowledgements section for more on packages and 3rd party software we use.
The principle behind cntp.me is pretty simple. When you shorten a URL, cntp.me stores the original long version in our database along with its new shortened alias. We either automatically generate an alias that's not in use or use the one you've specified (for custom shortened URLs).
When somebody visits the new shortened URL, cntp.me extracts the alias from the URL and looks it up in our database. We can then pull out the original URL and either redirect the visitor there immediately or display a preview page, depending on their preferences. We also log that the visit happened so that we can include it when we update our statistics. All of this happens extremely quickly.
Although the principle is pretty simple, the reality of serving hundreds or thousands of requests every second is a little more complex. We do things like caching details on frequently used URLs on our web servers so that we can serve them very efficiently as soon as a request comes in.
Spam and abuse
We're one of the most proactive URL shorteners in combating service abuse. Please read our spam policy for a list of some of the many measures we're taking to prevent abuse of our service.
Check whether the link's content or the way you used it violated our terms. If not, the URL may have been added to a blacklist that we consult - if you try to create a new link with the same destination our site should tell you which of the blacklists we use the URL is on so that you can attempt to get it removed. If it's inappropriately on our internal blacklist or if none of these things apply, please contact us so that we can look into it since mistakes are very occasionally made (we can easily reinstate disabled links if so).
Misc
cntp.me and is.gd are sister services, but are two separate URL shorteners. They're run by the same team and on the same platform, so their functionality is very similar. The main difference between them is that cntp.me displays a link preview page by default whenever somebody visits one of its shortened URLs, but is.gd doesn't (by default it sends people straight to the link's destination). For this reason cntp.me can be seen as a slightly "safer" option and is handy for users who always want to know where a link goes before clicking it.
We originally planned to implement previews as the default on is.gd as well, but changed our plans on this because it broke some legacy is.gd links people had embedded directly in webpages as images, was confusing to non-English users, and wasn't popular with is.gd's large existing user-base. The preview page can still be enabled as an option on is.gd on a per-user basis.
Unfortunately not. We want to keep cntp.me as fast and clean for our users as possible, so aren't allowing any 3rd party advertising on the site.
When cntp.me serves up redirects it always uses 301 (permanent) instead of 302 (temporary), so does pass on SEO credit to your link. As you may have noticed we serve up a preview page instead of a redirect to users by default, however the default is different for search engines crawlers and other things we detect as automated services. We ensure they're served a 301 redirect rather than the preview page to make sure that your shortened links are crawled and credit passed on appropriately.
Because the only accesses that the counter "knows" about instantly are those served by the same web server that's handling your request. Once every minute the counter will factor in the counts from our other servers to get the real value, which causes it to jump up. It can also sometimes jump around or appear to count down if your requests are handled by different servers.
cntp.me is short for "very good". We chose this domain because cntp.me was originally developed to be an improvement on our other service, is.gd, which stands for "is good". They have since been ported to the same architecture, so should be equally "gd".
cntp.me uses a few pieces of open source software as well as some free services to help us on our quest to URL shortening nirvana: -
- Thanks to the developers of Open Flash Chart 2 (LGPL) which we use to draw statistics graphs. It's not too clear from the site who the main developer is, but let me know if you'd like a credit by name!
- Thanks to Chris Schuld for his excellent browser and platform detection PHP script (GPLv2).
- Thanks to Olivier Hill and any contributors for the PECL geoip package (PHP license) allowing geolocation. Also thanks to MaxMind for making their GeoLite database which is used by that package available.
- Thanks to Google for Google Charts which is used to provide QR codes.