urltodo

urltodo stores your list entirely in the URL. When you edit the list the URL changes. If you share the URL other people can see the same list. The link is the list.

Just go to urltodo.com, create your list, and then copy the url.

There's no accounts and no servers. You can bookmark your lists or embed them in a document like this. Lists never get deleted and every change you make is versioned in your browser history.

Creating URL Encoded Todo Lists with scripting and urltodo

You can programmatically create URLs that can be opened as lists in urltodo.com. You just need to create a valid TodoList JSON object and encode it correctly into a valid urltodo URL.

JSON Schema

interface TodoList {
	title?: string;       // Optional list title
	tasks: Task[];          
}

interface Task {
	id: string;           // Unique Id (recommended: Date.now().toString)
	text: string;         // Task content
	completed: boolean;   // Task completion status
}

Encoding process

URLTodo encodes a todo list into a URL using the following encoding chain:

JSON.stringify → encodeURIComponent → unescape → btoa

Each step in this chain serves a specific purpose:

1. encodeURIComponent converts all unicode characters into UTF-8 sequences. Without this step the URL would not be able to contain special characters like emojis.
2. unescape converts all percent-encoded sequences (%XX) back to their actual byte values. For ASCII characters, this just returns the original character. For special Unicode characters like emojis, it converts the percent-encoded UTF-8 byte sequences into raw UTF-8 bytes (not percent-encodings). Without this step the final encoding would be far longer (unless your list items are entirely emojis...)
3. btoa encodes everything as a base64 string which makes it URL safe and shortens the string considerably.

Note: unescape is a deprecated function but it is supported in all browsers and JavaScript run times.

Implementation examples

JavaScript

const groceryList = [
	"Milk",
	"Eggs",
	"Bread",
	"Bananas 🍌",
	"Coffee ☕",
	"Chicken",
	"Rice",
	"Tomatoes 🍅"
];

// Create a urltodo-compatible data structure
function createTodoData(items) {
	const tasks = items.map(item => ({
		id: Date.now().toString,
		text: item,
		completed: false
	}));
	
	return {
		title: "Weekly Groceries",
		tasks: tasks
	};
}

// Encode the data for urltodo
function encodeForUrlTodo(data) {
	const jsonString = JSON.stringify(data);
	return btoa(unescape(encodeURIComponent(jsonString)));
}

// Generate the full URL
function generateTodoUrl(encodedData) {
	return `https://urltodo.com/#${encodedData}`;
}

const todoData = createTodoData(groceryList);
const encodedData = encodeForUrlTodo(todoData);
const todoUrl = generateTodoUrl(encodedData);

console.log(todoUrl);

Python

import json
import base64

def encode_for_urltodo(data):
    """Encode data for URLTodo app using Python"""
    # Step 1: Convert to JSON string (equivalent to JSON.stringify)
    json_str = json.dumps(data)
    
    # Steps 2-3: Instead of encodeURIComponent + unescape, 
    # we directly encode the string to UTF-8 bytes
    utf8_bytes = json_str.encode('utf-8')
    
    # Step 4: Base64 encode (equivalent to btoa)
    base64_bytes = base64.b64encode(utf8_bytes)
    
    # Convert back to string for URL usage
    base64_str = base64_bytes.decode('ascii')
    
    return base64_str

# Example usage
todo_data = {
    "title": "Python Shopping List",
    "tasks": [
        {
            "id": "1743242653576",
            "text": "Apples 🍎",
            "completed": False
        },
        {
            "id": "1743242653913", 
            "text": "Bananas 🍌",
            "completed": True
        }
    ]
}

encoded_data = encode_for_urltodo(todo_data)
todo_url = f"https://urltodo.com/#{encoded_data}"

print(todo_url)

Limitations

There is an upward limit to the length of lists imposed by Chrome and FireFox's max URL lengths (32,000 and 64,000 characters). In practice these would be very long lists.

Links

1. GitHub Repo
2. My website