Sensing Blocks in Scratch

Sensing blocks are color-coded light-blue, and are used to detect different factors of a project.

There are currently 20 Sensing blocks: 4 Stack blocks, 5 Boolean blocks and 11 Reporter blocks.


Ask and Wait

The block will make an input box (with the specified text above it) show at the bottom of the screen. Scratchers can input text into it and submit it, and the input is stored then in the Answer block. The Answer block automatically updates to most recent input.

Reset Timer

The block sets the timer's value back to 0.0. When this block is present, the project typically utilizes the Timer output block; usually the timer must be reset at the beginning of a project for the Timer block to hold the right value.

Turn Video

The block can turn the webcam on, off, or on flipped horizontally, depending on the argument.

Set Video Transparency

The block sets the transparency of the video stream to a certain value.

TouchingThe block checks if its sprite is touching the mouse-pointer, edge, or another sprite. If the sprite is touching the selected object, the block returns true; if it is not, it returns false.

Touching Colour

The block checks whether its sprite is touching a specified color. If it is, the block returns "true".

Color is Touching

The block checks whether a color on its sprite is touching another color. If it is, the block returns "true".

Key is Pressed?

The block checks if the specified key is pressed. If the key is being pressed, the block returns "true"; if it is not, it returns "false".

Mouse Down?

The block checks if the computer mouse's primary button is activated (being clicked).

Distance to

The block reports the Euclidean distance, in pixels, between it and the mouse-pointer or a specified sprite's costume center.


The block holds the most recent text imputed with the Ask () and Wait block. When nothing has been inputted yet, the value will hold nothing.

Mouse X

The block holds (reports) the mouse-pointer's current Mouse X.

Mouse Y

The block holds the mouse-pointer's current Mouse Y.

LoudnessThe block reports how loud the noise is that a microphone receives, on a scale of 0 to 100. To use this block, a microphone must be used, and so a message will appear on the screen, asking for permission to use the microphone. If you deny it, the block will report a loudness of 0 or -1.


The block starts at 0 when Scratch is launched and increases gradually; every second it will have increased by 1.

VideoIt gets values of the video, either motion (on a scale of 1 to 100) or direction (which way the detected motion is going, measured on the same plane as sprite direction), on either the Stage, or the current sprite.

SensingThe block will report a specified value of the specified sprite or the Stage.

CurrentIt reports either the current local year, month, date, day of the week, hour, minutes, or seconds, depending on the argument. The block gets the data based on the user's computer's clock and set in 24-hour clock.

Days Since 2000

It reports the amount of days (and fractions of a day) since 00:00:00 1 January 2000 (UTC).


It reports the username of the user viewing the project.

The above information is referenced from Scratch Wiki.