What is Blockly?

Written by Ucode Research on August 30, 2019

Blockly is the successor to Google’s App Inventor, itself inspired by MIT’s Scratch. It is a visual block programming editor that acts as a library for adding drag-and-drop block coding to an app. The name Blockly is based on its user interface which resembles a child’s toy box, consisting of multi-shaped, multi-colored blocks.

Blockly is primarily used for computer science education, but can also give users a way to write their own scripts or configuration for other applications. It has libraries allowing apps to be exported to Web (JavaScript), Android (Java), and iOS (Swift/Obj-C) platforms. Blockly works by linking colored blocks of code to a function and rendering the result. Each block type usually illustrates a concept or some type of conditional logic that is used in ‘real world’ programming languages .

Development of Blockly began in the summer of 2011, and was introduced to the public at the May 2012 Maker Faire event in San Mateo, California. Blockly was developed for kids to learn at home or at school within the browser. Blockly is often compared to Scratch, though is much more open-ended and is generally more difficult to learn.

Google and MIT’s Scratch Team have recently collaborated on the development of a new generation of graphical programming blocks, called Scratch Blocks. Scratch Blocks combines Blockly technology with the Scratch team’s expertise in designing creative interfaces for young learners. It is beginner-friendly with an icon based UI and is designed specifically blockly programming for younger kids. Scratch 3.0, the most recent release, was rewritten as a fork of Blockley.


  1. https://opensource.google.com/projects/blockly
  2. https://developers.google.com/blockly/