Mblock 3.4.12 May 2026

Why would a user ignore modern software to install an older version? The answer lies in three specific features that are broken, removed, or overly complicated in later releases.

mBlock 3.4.12 is a legacy version of the popular graphical programming environment based on Scratch 2.0. While newer versions (mBlock 5) offer cross-platform and AI/IoT capabilities, version 3.4.12 remains widely used for its stability, offline functionality, and native support for Arduino code generation. This paper provides a technical overview, installation guidance, use cases, and troubleshooting tips for mBlock 3.4.12.

To understand the value of mBlock 3.4.12, we must rewind to the mid-2010s. At that time, Scratch 2.0 was the king of visual programming for kids. However, Scratch had a massive limitation: it could not talk to hardware. You couldn’t blink an LED or move a servo motor using vanilla Scratch. mblock 3.4.12

Enter Makeblock, a Chinese robotics company famous for the "Codey Rocky" and "MegaPi." They developed mBlock—a modified version of the Scratch 2.0 source code.

mBlock 3.4.12 is widely considered the most stable and feature-complete release of the Scratch 2.0-based mBlock series. Why would a user ignore modern software to

Unlike later versions (3.5.x and 4.x) which introduced bugs or removed features, 3.4.12 struck the perfect balance.

Yes, but with caveats.

Use it if:

Do not use it if:

At its core, mBlock 3.4.12 is a modified version of Scratch 2.0. It allows you to program sprites and stage performances using drag-and-drop blocks. The magic lies in the "Arduino Mode" . With a single button, you can convert that block code into actual C++ code (via the Arduino IDE in the background) and upload it to an Arduino Uno, Mega, Nano, or Makeblock自家的 robots (like the mBot).