I currently wish to use the shortcut to increase or decrease brush size in Photoshop by selecting a brush and option clicking then dragging to the left or right. This brings up a red brush preview and the hardness can be adjusted by moving up and down with the mouse.

For some reason this functionality doesnt work on my Mac running Photoshop CS6. As soon as I press option, the eyedropper tool opens instead. Any thoughts would be helpful.

Many thanks.

  • mine seemed deactivated but it was that the language keyboard changes by itself...
    – zonia
    Commented Jul 6, 2018 at 0:49

5 Answers 5


] - Increase Brush Size
[ - Decrease Brush Size

  • Note: it doesn't work with french keyboard layout. Only ALT+right click works.
    – Basj
    Commented May 27, 2020 at 20:51

For Mac users:

Option + Right mouse button = brush size (left <-> right) & hardness (up <-> down)

Option + Left mouse button = Eyedropper tool

For Windows users:

Alt + Right mouse button = brush size (left <-> right) & hardness (up <-> down)

Alt + Left mouse button = Eyedropper tool


Downgrade previous gen Wacom driver: MacOSX 6.3.21-8 to resolve PS CC brush resize/hardness with Ctrl + Alt.

Wacom Previous Drivers


I noticed that that it wasn't working for me one time, and my mistake was that I was not doing the right clicking on the image canvas itself.

If not already doing so, try doing the "alt + right-click + drag" shortcut to resize the brush on the actual image canvas instead of on the blank space outside of it. This may seem obvious but it took me a while to figure out.


The same thing happened with me.

This is my way: open Edit/keyboard shortcuts and menus

In the keyboard shortcuts panel, choose Tools, at Eyedropper tools, delete everything you found there, I means EVERYTHING. AND ACCEPT/OK.

And it comes back to normal, now I can use Control + option, move mouse to left/ right to change th brush size.

Hope this will help

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