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 and fits anywhere, including on a slide or in print.
- The short link is also 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 else a shortener does
Most shorteners offer more than the redirect:
- QR codes for every link, for the offline world.
- Analytics: how many clicks, and from which countries, devices and sites.
- Branded domains so the link carries your name instead of a shared short domain (here is why shared short domains get blocklisted).
- Controls like expiry, password protection, and geo/device targeting.
- An API to create links from your own code.
Urlicer has all of these. QR codes, analytics and the API are on every plan, free included. Custom aliases, branded domains, expiry and password protection start on Pro, and geo/device targeting and A/B tests on Team. Links you keep in a workspace never expire unless you set an expiry.
Want to see it in action? Start with a free account. Links in your workspace never expire, and every one gets a QR code and click analytics.