How URL Shorteners Work — The Technology Behind the Short Link

What Actually Happens When You Click a Short Link

You click https://toolbeans.com/s/ab3x and end up at a completely different, much longer URL. The process behind this takes milliseconds and involves a few specific steps.

Your browser sends a GET request to the URL shortener's server. The server looks up the short code (ab3x in this case) in its database. If found, the server responds with an HTTP 301 (permanent redirect) or 302 (temporary redirect) that includes the destination URL in the Location header. Your browser automatically follows the redirect and loads the destination page.

The whole process happens so fast that users rarely notice the intermediate step. From their perspective, they clicked a link and the page loaded.

301 vs 302 Redirects — Why It Matters

This distinction is important and often gets glossed over.

A 301 Permanent Redirect tells browsers and search engines that the original URL has permanently moved to the destination. After the first visit, most browsers cache this redirect — meaning subsequent clicks skip the shortener server entirely and go straight to the destination. This is faster for users but means the shortener loses the ability to track clicks or change the destination URL.

A 302 Temporary Redirect tells browsers this is a temporary forward. Browsers do not cache it (or cache it briefly). Every click goes through the shortener server. This allows click tracking, analytics, and the ability to update the destination URL after the short link is already published. Most URL shorteners use 302 for this reason.

How the Short Codes Are Generated

The short code — that 4–7 character string after the domain — is generated in one of two ways.

Random generation — A random string of characters from a defined alphabet (usually letters and digits, case-sensitive or not) is generated and checked against existing codes for uniqueness. This is simple and scales well.

Sequential ID encoding — The database auto-increments an integer ID for each new URL. That integer is then encoded in a short base (base 62 using letters and digits is common). The number 1,000,000 in base 62 is just "4c92" — four characters. This approach is predictable, guaranteed unique, and efficient.

URL Shorteners and Privacy

When you click a short link, the shortener knows your IP address, browser, operating system, referring page, and the time of the click — even before you arrive at the destination. Commercial URL shorteners use this data for analytics.

This is worth knowing both when using short links and when sharing them. The link creator often sees aggregated click data. Some shorteners sell or share this data.

Creating Short URLs

Our URL Shortener tool creates short links instantly. Paste any long URL and get a short, copyable link. No account, no tracking by us — just a shorter link that is easier to share, especially in contexts where long URLs get truncated or look unwieldy.