A terse, human-readable, URL-safe encoding for JSONish strings.
Use this when you need to encode a string to make it URL-safe, but you also want to keep it as small and readable as possible (unlike base64). For example:
| Input string | base64 | utf64 | | ----------------- | ------------------------ | ------------------ | | Hello | SGVsbG8= | YHello | | "Hello!" | IkhlbGxvISI= | AYHelloGA | | {"Hello":"world"} | eyJIZWxsbyI6IndvcmxkIn0= | MAYHelloAFAworldAN |
I made this because I wanted to build a web API with a nice JSON schema that could also be cached by a CDN. To make it cacheable, I had to use the GET method; but GET can't (portably) have a request body, so this means all the API parameters need to be packed into the URL. UTF-64 is a fire-and-forget way to solve this problem.
UTF-64 uses the very permissive 0BSD licence so you can freely use this code & spec anywhere. I picked 0BSD as it seems to be the "public domain equivalent" most widely accepted by corporations, e.g. Google has a specific exception permitting the use of 0BSD.
npm install utf64
``` import * as utf64 from "utf64";
console.log(utf64.encode("Hello!")); console.log(utf64.decode("YHelloG")); ```
pip install utf64
``` import utf64
print(utf64.encode("Hello!")) print(utf64.decode("YHelloG")) ```
go get utf64.moreplease.com
``` package main
import ( "fmt" "utf64.moreplease.com" )
func main() { fmt.Println(utf64.Encode("Hello!")) result, err := utf64.Decode("YHelloG") if err != nil { panic(err) } fmt.Println(result) } ```
Kindly contributed by @mjmusante
cargo add utf64
``` use utf64::*;
fn main() { println!("{}", "Hello!".encodeutf64().unwrap()); match "YHelloG".decodeutf64() { Ok(result) => println!("{result}"), Err(e) => panic!("{e}"), } } ```
The JS package includes a utf64 command-line tool:
npm install -g utf64
utf64 "Hello\!"
utf64 -d YHelloG
Output is encoded using base64url-compatible characters: _ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-
| utf64 | Decoded as |
| ----------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| _ | As-is |
| a to z | As-is |
| 0 to 9 | As-is |
| ABCDEFGHIJKLMNOPQRSTU | Mapped to: "',.;:!?()[]{}#=+-*/\ |
| V | Newline |
| W | Space |
| X | Prefix for Unicode 0-63. For example, "Xk" is "%" (U+0025) |
| Y | Prefix for Unicode 64-127. For example, "Y_" is "@" (U+0040) |
| Z | Prefix for Unicode 128+. The following characters are interpreted as UTF-8, reduced to 6-bit bytes by stripping the redundant top two bits. For example, "ZhBr" is "€" (UTF-8 [11]100010 [10]000010 [10]101100) |
See test.json for tests that (hopefully) cover all the edge cases, for both valid and invalid encodings.