Little Big Details

Gov.uk - if you add /info/ before a page url, you will see the metrics of that page.

Example :

https://www.gov.uk/renew-driving-licence

https://www.gov.uk/info/renew-driving-licence

Shopify - The URL parameters include a check for UTF-8 Support, but instead of a simple boolean or ‘yes’ to designate, it uses the UTF-8 character for a checkbox (U+2713) to flag the support. 

/via Matthew

Medium - When you click on someone’s recommended content list the URL forms a phrase: [username]/has-recommended

/via Marina Janeiko 

Google Docs - When hyperlinking text in a Google document, it automatically suggests the URL based on the anchor text.

/via Yamini Sharma

Facebook - The url for the Facebook 404-page is /4oh4.php

Chrome - When a page is not found, it shows a suggestion of a similar correct url.

/via AMYunus

Pocket - When installing the bookmarklet, the URL field is used to give extra guidance.

/via Carbon Costume

SoundCloud – When searching for sounds longer than 30 minutes, it displays the filter variable as “epic”.

/via Mike Kotsch

Pocket (iOS) - After copying a URL, opening the Pocket app will automatically prompt you to save the content.

/via Myles Tan

Google+ - When posting a link to Google Plus, it replaces the URL with the title of the page the URL points to.

/via Wouter van Vliet