What is a URL shortener, and how does it actually work?
A URL shortener takes a long web address and gives you a short one that redirects to it. https://example.com/very/long/path?utm_source=… becomes something like ivi.to/aX9k2. Click the short one and you land on the long one.
Why bother shortening a link?
- Long URLs are ugly, hard to share, and easy to break when they wrap in an email or a chat.
- A short link is tidy, looks trustworthy, and fits anywhere, including on a slide or in print.
- Crucially, the short link is a layer you control: you can measure clicks and even change the destination later.
How the redirect works under the hood
When you create a short link, the shortener stores a mapping (this short code points to that destination) and gives the code back to you. When someone visits the short link, the server looks up the code and responds with an HTTP redirect to the real address. The browser follows it, and the visitor arrives. The whole round-trip takes milliseconds.
Good shorteners make that lookup extremely fast (often from an in-memory cache) because the redirect sits in front of every single click, so speed matters.
How short codes are generated
The short code is usually a compact, base-62 string (letters and numbers). A well-designed shortener generates these so they never collide, even across many servers, and lets you set a custom alias when you want a memorable link instead of a random one.
What modern shorteners add
Shortening is table stakes. The value today is in what wraps around it:
- QR codes for every link, for the offline world.
- Analytics: who clicked, from where, on what.
- Branded domains so the link carries your name.
- Controls like expiry, password protection, and geo/device targeting.
- An API to create links programmatically.
Urlicer does all of the above, and its links are permanent by default, so the short link you make today still works years from now.
Want to see it in action? Shorten a link free. No signup, and every link gets a QR code and click analytics.