Block-based coding is for all programmers, of any field or level. Explore the latest from Blockly and connect with other developers at our Blockly Summits.

It utilizes puzzle-piece blocks to represent code elements, allowing users to program without syntax concerns. Developers define block connections and the resulting code strings. Blockly handles rendering, dragging, and string concatenation.

December 10, 2025 - Blockly provides a script that bootstraps a starter application, which you can then modify. It uses common web development tools like webpack and eslint, but doesn't include a framework, like React or Angular.

Blockly Developer Tools is a web-based tool for building and including custom blocks in your application.

A few Blockly applications omit the "Run" button and instead update the output panel every time the user makes a change. For example, the Graph application in Blockly's samples has two output panels (one for the graph and one for the equation) that it updates on every change.

February 19, 2026 - Blockly is a client-side library for the programming language JavaScript for creating block-based visual programming languages (VPLs) and editors. A project of Google, it is free and open-source software released under the Apache License 2.0. It typically runs in a web browser.

Many Blockly applications are used to describe configurations, rather than executable programs. Configuration applications typically start by initializing one root level block on the workspace. A good example is the Block Factory tab of the Blockly Developer Tools:

June 9, 2017 - Over the past five years, developers have created hundreds of projects with Blockly, our open source library for creating block-based coding experiences. These have ranged from education platforms like Code.org to electronics kits like littleBits ...

December 10, 2025 - Blockly uses some tools and libraries for development, including Git, npm, and the Closure Compiler.

Key strengths of Blockly include its availability on NPM, full feature set with multi-language code generation and a plugin ecosystem, high customizability, internationalization support for over 90 languages, and its open-source nature.

You can't "run" blocks directly. Instead you generate code strings, and then execute those. To generate code, you have to pick what text-based language you want to generate. This is because each language has its own code generator.

Blockly is made up of over a hundred TypeScript files. These must be compiled by the TypeScript compiler, tsc, into JavaScript before they can be used. This creates an equally large number of .js files which are suitable for local testing, but loading such a large number of files over the Internet is a sluggish experience for end users.

Blockly has many resources for learning how to use the library. Start at our Developers Site to read the documentation on how to get started, configure Blockly, and integrate it into your application.

The Blockly developer process using the tool consists of three parts: Create custom blocks using Block Factory and Block Exporter. Build a toolbox and default workspace using Workspace Factory.

December 10, 2022 - Tools for Blockly app developers to help build custom blocks. - google/blockly-devtools

This discusses some special features of the JavaScript code generator, as well as JSInterpreter, which the Blockly team recommends as a way to safely execute JavaScript. Other languages require other tools. Except as otherwise noted, the content of this page is licensed under the Creative Commons Attribution 4.0 License, and code samples are licensed under the Apache 2.0 License. For details, see the Google Developers Site Policies.

Archive · Skip to content · The Google Code Archive requires JavaScript to be enabled in your browser · Google · About Google · Privacy · Terms

Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message ... As I said: I am also not familiar with that code. You are going to need to either explore more parts of the blockly games source, including parents and child directories, or else use developer tools to inspect the page to understand what's going on.

The Blockly playground is a useful tool for testing, debugging, or prototyping core Blockly or plugin development.