SnoopX
A pixel inspector for macOS with HDR support
SnoopX captures raw pixel R, G, B values and reports them for the pixel
under the red square — 8-bit integers when in SDR mode, 16-bit floats
when in HDR mode — at the bottom of the window.
Magnification
| 1 2 4 8 0 |
Set magnification to 1x, 2x, 4x, 8x, or 16x. |
Capture Control
| k | Freeze or unfreeze the capture location. |
| u | Update the capture once (while frozen). |
| ← → ↑ ↓ |
Nudge the capture location by one physical pixel. |
| ⇧+arrow |
Nudge by 10 pixels. |
The window can be expanded or shrunk by grabbing its edges or corners.
If you want to simultaneously inspect two locations, make a copy of the app.
Near the edge of the screen, a checkerboard indicates pixels beyond the screen.
SDR and HDR Display
| ⌃A | Auto — choose Standard Dynamic Range (SDR) or High Dynamic Range (HDR) based on display capability. |
| ⌃S | SDR — pixel values reported in the range 0–255. |
| ⌃H | HDR — pixel values reported in f-stops, where 1.0 = 256, as in Adobe Lightroom. |
EDR Rendering
| ⌃G | Gamma — matches what you see on screen, but clamps to the display’s dynamic range. |
| ⌃L | Linear — can display any dynamic range, but washes out colors. |
Scanline Plots
Drawn inside the snoop window along the indicator row or column.
Press the hotkey again to turn the plot off, or press o to turn off
any plot.
| p | Horizontal plot of pixel values along the indicator row. |
| v | Vertical plot of pixel values along the indicator column. |
| ⇧P | Horizontal step plot (one bar per pixel). |
| ⇧V | Vertical step plot (one bar per pixel). |
| l | Show or hide the indicator line marking the plotted row or column. |
Color Plots
Opens a popup window that re-renders whenever the snoop window updates,
showing the distribution of all pixels currently in the snoop window. Press
the hotkey again to turn the plot off, or press o to turn off any
plot.
| c | Color vectorscope — hue-saturation-value scatter plot of all snooped pixels. |
| w | Color waveform — chroma trail by column. |
| h | Color histogram — per-channel pixel distribution. |
Statistics and Swatch
| i | Show or hide statistics (min, max, mean, median) for all pixels in the window. |
| s | Display a swatch of the snooped color. |
Plot ordinates follow the display mode: 0–255 for SDR, f-stops for HDR.