Shortcut comparison

Viewport
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
PanSpace+dragSpace+dragSpace+dragSpaceSpace+drag
Middle button+dragMiddle button+dragMiddle button+dragMiddle button+dragMiddle button+drag
Zoom inCmd+PlusCmd+PlusCmd+PlusPlusCmd+Plus
Zoom outCmd+MinusCmd+MinusCmd+MinusMinusCmd+Minus
Zoom 100%Cmd+1Cmd+1Cmd+11Cmd+1
Fit to windowCmd+0Cmd+0Cmd+0Shift+Cmd+JCmd+0
Transform
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
Image sizeOption+Cmd+IOption+Cmd+IOption+Cmd+I– –Option+Cmd+I
Canvas sizeOption+Cmd+COption+Cmd+COption+Cmd+C– –Option+Cmd+C
Free transformCmd+TCmd+TxShift+TShift+Cmd+T
Changing items in view
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
RGB color channelCmd+2Cmd+2– –– –x
Red color channelCmd+3Cmd+3– –– –x
Green color channelCmd+4Cmd+4– –– –x
Blue color channelCmd+5Cmd+5– –– –x
Toggle rulersCmd+RCmd+RCmd+RShift+Cmd+RCmd+R
Toggle guidesCmd+;Cmd+;Cmd+;Shift+Cmd+TCmd+Option+;
Constraining
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
Marquee square/circleShiftShiftCommandShiftShift
Crop original aspect ratio– –Shift– –Shift– –
Brush stroke vertical/horizontalShiftShiftShift– –Shift
Non-proportional scalingShiftShiftShiftShift– –
Layer management
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
New layerShift+Cmd+NShift+Cmd+NShift+Cmd+NShift+Cmd+NShift+Cmd+N
Merge downCmd+ECmd+ECmd+E– –Cmd+E
DuplicateCmd+JCmd+JCmd+JShift+Cmd+DCmd+J
Modifier to create new layer belowCommandCommand– –– –– –
Rename– –Enter– –– –– –
Hide/showCmd+,, (comma)– –Enter??
Selection
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
DeselectCmd+DCmd+D
Escape
Cmd+DShift+Cmd+ACmd+D
InvertShift+Cmd+IShift+Cmd+IShift+Cmd+ICmd+IShift+Cmd+I
Composite luminosityCommand-click RGB channelCommand-click RGB channel??– –– –
Layer luminosity– – [1]??????
Modifier key:
Add
ShiftShiftShiftShiftShift
Modifier key:
Subtract
OptionOptionOptionCommandOption
Modifier key:
Intersect
Shift+OptionShift+Option– –Shift+CommandShift+Option
Painting
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
Resize brush by keyboard[ and ][ and ][ and ][ and ][ and ]
Resize brush by mouseCtrl+Option+dragCtrl+Option+dragCtrl+Option+drag– –– –
Clear mode` (backtick)` (backtick)– –??` (backtick)
Connect straight lineShiftShiftShiftShiftShift
Colors
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
Swap FG and BGXXXXX
Reset to black and whiteDDDDD
Text
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
Change font size (fine)Shift+Cmd+< >Shift+Cmd+< >Shift+Cmd+Option+< >– –Shift+Cmd+< >
Change font size (coarse)Shift+Cmd+Option+< >Shift+Cmd+Option+< >Shift+Cmd+< >– –– –
Bold– –Cmd+B– –Cmd+BCmd+B
Italic– –Cmd+I– –Cmd+ICmd+I
Underline– –Cmd+U– –Cmd+UCmd+U
Apply editsCmd+EnterCmd+EnterCmd+Enter– –Cmd+Enter
Adjustments
Photoshop 2026Mojave PaintAffinity Photo 2GIMP 3Acorn 8
CurvesCmd+MCmd+MCmd+M– –Shift+Cmd+M
LevelsCmd+LCmd+LCmd+L– –Cmd+L
Hue/SaturationCmd+UCmd+UCmd+U– –– –
InvertCmd+ICmd+ICmd+ICmd+I– –
DesaturateShift+Cmd+UShift+Cmd+U– –– –– –

Legend

Blue Text– –x??   
Matches PhotoshopNo shortcut (but feature is accessible other ways)Feature does not existUnsureNot investigated
[1] No direct way to select a layer's luminosity in Photoshop but doable with workarounds such as:
  1. Hide all other layers then select composite luminosity by cmd-clicking the RGB thumbnail
  2. Select all and copy pixels from a layer, paste into an alpha channel, then cmd-click the alpha channel thumbnail to make a selection