Sanitized, well formed JSON is generally not horribly URL encoded. It's typically less overhead than base64. Also, for well formed JSON (not arbitrary JSON),

Sanitized, well formed JSON is generally not horribly URL encoded. It's typically less overhead than base64. Also, for well formed JSON (not arbitrary JSON), it also works fine in HTTP headers. I think those two situations cover about 90% of use cases. For example, here is a JSON payload URL encoded. It's not too bad, and much better than base64: https://cyphr.me/coze#?input={%22pay%22:{%22msg%22:%22Hello%20Retr0id!%22,%22alg%22:%22ES256%22,%22iat%22:1701603747,%22tmb%22:%221KGZzsqiFAYE5uDO3CCh3PMl9pqwlG1RrI8i5gZY94c%22,%22typ%22:%22cyphr.me/msg/create%22},%22sig%22:%22vZEALUQShRlLYyhJoGmkxpQhhEeUPlzbIZqyTsUyPBMlJMIqGClgSs3uXTDiwumsMivFQKU8K4z4Ec7WlxYIew%22}&dontSignRevoke&updateIat&selectedAlg=ES256&verify https://cyphr.me/coze#?input={%22pay%22:{%22msg%22:%22Hello%... The initial payload is 238 bytes, URL encoded that payload is 288 bytes, as base 64 it is 318 bytes. (Here's another tool just for that: https://convert.zamicol.com/#?inAlph=text&in=%257B%2522pay%2522%253A%257B%2522msg%2522%253A%2522Hello%2520Retr0id!%2522%252C%2522alg%2522%253A%2522ES256%2522%252C%2522iat%2522%253A1701603747%252C%2522tmb%2522%253A%25221KGZzsqiFAYE5uDO3CCh3PMl9pqwlG1RrI8i5gZY94c%2522%252C%2522typ%2522%253A%2522cyphr.me%252Fmsg%252Fcreate%2522%257D%252C%2522sig%2522%253A%2522vZEALUQShRlLYyhJoGmkxpQhhEeUPlzbIZqyTsUyPBMlJMIqGClgSs3uXTDiwumsMivFQKU8K4z4Ec7WlxYIew%2522%257D&outAlph=b64ut https://convert.zamicol.com/#?inAlph=text&in=%257B%2522pay%2...)