Powerful coding, block by block
Blockly is a visual programming editor by Google that uses drag-and-drop blocks. It’s the engine that powers the most popular coding education programs world wide.
Blockly for Web
Blockly is 100% client side, with no server side dependencies, and compatible with all major browsers: Chrome, Firefox, Safari, Opera, and Edge.
The Blockly library offers a comprehensive suite of APIs and tools, empowering coding platforms to provide a customizable environment for their unique requirements.
The Blockly editor uses interlocking, graphical blocks to represent code concepts like variables, logical expressions, loops, and more. It allows users to apply programming principles without worrying about syntax.
A platform-agnostic library, Blockly is preferred by coding platforms seeking consistency, flexibility and convenience. Blockly is compatible with all major browsers and works on both web and mobile.
Build with Blockly
Create unique tools, applications, and platforms that meet your specific program requirements.
Add functionality to Blockly with Plugins. Add fields, define themes, create renderers, and much more.
Blockly codelabs provide step-by-step instructions on how to use and customize Blockly.
Sample projects show how to use many of Blockly's features.
The Blockly Developer Forum is the place to ask and answer questions.
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.
Blockly provides a really good entry point into computer science, without worrying about things like a missing semicolon, or a for loop that doesn’t have all of the right pieces.
Jessica Kulwik, Software Engineering Manager, Code.org
App Inventor would simply not be the success that it has been (with >1M active users per month) without Blockly, and perhaps more importantly, the support of the Blockly team! They have been true partners in our success.
Mark Friedman, Co-founder, App Inventor
Teach with Blockly
Code a hero with Scratch for CS First
Use the force of coding
Build your own Star Wars game with Blockly and Code.org
Create a world
Imagine a world and make it come to life with Scratch
How can I get started with Blockly?
If you are a software developer who wants to get started with Blockly, you should begin by reading our Get Started Docs and then try our Get Started Codelab.
If you are a teacher or student interested in block-based coding, you should check out a lesson through an educational product built on Blockly, such as CS First, Code.org, or Scratch.
Who is Blockly for?
The Blockly library is for software developers that want to add an editor to their app that represents coding concepts as interlocking blocks. From a developer's perspective, Blockly is a ready-made UI for creating a block-based language.
If you are not a developer, you most likely will want to engage with Blockly through a product that is built on Blockly, like Scratch or App Inventor. Check out the Blockly partnerships section for examples of other applications that are built on Blockly.
What are some of the benefits of block-based coding?
Block-based coding allows users to apply programming principles without having to worry about syntax or the intimidation of a blinking cursor on the command line, making the learning curve for aspiring programmers easier. By reducing the need to learn syntax, block-based coding allows users to focus entirely on the logic behind conditionals, loops, variables and other core concepts without worrying about unbalanced parenthesis or missing semicolons.