This is an exhaustive list of all supported and unsupported blocks. If a block is missing from this list, or if a block has an incorrect behavior which is not documented here, please open an issue.
Extensions which are not yet supported are not on this list.
Thanks to scratchblocks for generating these images.
All motion blocks are fully supported.
Looks speech bubble blocks are not yet supported. Text is instead printed to the console window. Speech blocks with a delay will still wait for the correct amount of time.
A limited number of graphic effects are functional. Currently, only the color, brightness, and ghost effect blocks work as expected. Clearing graphic effects also works correctly.
All other looks blocks are fully supported
The when greater than block is not full implemented. In particular, the microphone is not supported so when loudness is greater than does not work. The when timer greater than block might work as expected.
All other event blocks are supported. Note that there are some edge cases where events will run in a different order than expected. Most projects will run correctly, but some which rely on Scratch to order events in a very specific way may have issues.
All control blocks are fully supported.
The sensing color blocks do not yet work, but they should be added in the future.
The sensing ask blocks do not yet fully work. Using them will show a prompt in the console window, which will hang the program.
Sprite dragging not implemented, so the set drag mode block does not work.
The microphone does not work, so the loudness sensing block does not report loudness.
All other sensing blocks are fully implemented.
All operator blocks are fully implemented.
Variable monitors are not yet supported. Using the show block on a variable will print its current value to the console, however.
All other variable and list blocks are fully implemented.
Custom blocks with arguments and with "run without screen refresh" are fully implemented.
All pen blocks are fully implemented. Note that the pen does not always draw exactly as expected, so there may be a few differences. A few glitches with the pen clipping on the screen have also been observed.
Hidden blocks
Some hidden blocks are supported and act as expected. Notably, the all at once
block
functions and runs its contents without screen refresh.