"What is the world's shortest URL?" seems simple but is surprisingly deep. URL length comprises protocol (https://), domain name, and path, so pursuing the shortest URL means considering how short each element can be. The theoretical shortest URL is something like `http://a.co` at just 11 characters (12 for https). But the shortest actually accessible URL is more complicated.
For shortest domain records: domain names consist of a second-level domain (SLD) plus top-level domain (TLD). The shortest SLD is 1 character, and single-character .com domains actually exist: `x.com` (acquired by former Twitter), `z.com` (long held by Nissan, later sold), `q.com` (held by CenturyLink). Only 26 single-character .com domains can exist (a-z), all registered in the 1990s. Current market value is estimated at millions to tens of millions of dollars each. `x.com` made headlines when Elon Musk used it for Twitter's 2023 rebrand, though he originally acquired it in 1999 for his online bank X.com (later PayPal). Domain trivia books are available on Amazon.
TLD shortness directly affects URL length. The shortest TLDs are 2-character country-code TLDs (ccTLDs): `.ai` (Anguilla), `.io` (British Indian Ocean Territory), `.ly` (Libya), `.to` (Tonga). These 2-character TLDs were originally assigned to their countries but became popular with tech companies because they match English words. `.ly` is widely used by short URL services, `.io` became the standard for tech startups. Fascinatingly, these small nations earn enormous revenue from domain registrations. Tuvalu (`.tv`) sold `.tv` domain operating rights to a US company for $50 million in 2000, using the income to fund UN membership fees.
The domain shortness competition among short URL services has interesting history. From TinyURL (tinyurl.com: 11 characters), domains shortened to bit.ly (6), goo.gl (6), ow.ly (5), and t.co (4). Twitter's `t.co` is among the shortest major short URL service domains. Domain shortness offers practical benefits beyond character limits: memorability and verbal communicability. When reading URLs on radio or TV, domain shortness significantly affects information delivery efficiency.
As ultimate URL trivia: you can access web pages without URLs by entering IP addresses directly. `http://142.250.196.110` reaches Google's server. IP addresses can even be entered as decimal integers: `http://2398801518`, interpreting the four IPv4 octets as a single 32-bit integer. Some browsers support this format, though it's sometimes exploited in phishing attacks for URL obfuscation. The world of URLs grows deeper the more you pursue shortness.