TinyURL

Seconds per day -> 24 * 3600 -> 10^5

base64 encoded -> each base64 character encodes 6 bits value

Using base64 encoding, a 6 letter long key would result in 64^6 = ~68.7 billion possible strings
Using base64 encoding, an 8 letter long key would result in 64^8 = ~281 trillion possible strings

URL-Encoded [TODO]

Modern day server -> 256 GB memory