A simple base62 encoded token library for go, ideal for short url services.

go get



This is a simple package for go that generates randomized base62 encoded tokens based on an integer. It's ideal for short url service or for any short, unique, randomized tokens you need to use throughout your app.

How it Works

Token is an alias for uint64.

The Token.Encode() method returns a base62 encoded string based off of the uint64.

Token implements the json.Marshaler interface to encodes and decoded to and from the base62 string representation of the uint64

Basically, the outside world will always see the token as a base62 encoded string, but in your app you will always be able to use the token as a uint64 for fast, indexed, unique, lookups in various databases.

IMPORTANT: Remember to always check for collisions when adding randomized tokens to a database


package main

import (

type Model struct {
    ID  token.Token `json:"id"`

func main() {
    // create a new model
    model := Model {
        ID: token.New(), // creates a new, random uint64 token
    fmt.Println(model.ID)          // 2751173559858
    fmt.Println(model.ID.Encode()) // Mr1NSSu

    // encode the model as json
    marshaled, err := json.Marshal(&model)
    if err != nil {
    fmt.Println(string(marshaled)) // {"id":"Mr1NSSu"}

    // decode the model
    var unmarshaled Model
    if err := json.Unmarshal(marshaled, &unmarshaled); err != nil {
    fmt.Println(unmarshaled.ID)    // 2751173559858


Special Mentions

Special thanks to @einsteinx2. The encode and decode functions are ported from a short url project of his and he graciously allowed me to publish them.