Some of the best websites answer exactly one question: is this site down, what time is it there, what is my IP address. They load fast and get out of the way.
A clear promise
When a site does one thing, its name and URL often explain it completely. Visitors know what they will get before the page even loads.
Easy to share
Single-purpose sites travel well. They fit in a message, a tweet, or a bookmark folder without any explanation.
Easy to finish
For builders, a focused idea is a project you can actually complete in a weekend. Shipping something small teaches more than planning something enormous.
Find more
base31's tools page collects dozens of small, focused utilities. Each one began as a simple idea that someone decided to finish.