Pick colors and measure pixels
Updated October 24, 2026
Two tools for people who work in pixels: Pick Color copies the color of any pixel on screen, and Measure is a ruler that snaps to edges. Both work on a frozen picture of the screen.
Pick Color
Choose Pick Color in the menu bar menu. The screen freezes as it is, with no dimming, and the magnifier follows the pointer. Its center cell is the pixel a click copies, stroked white over dark pixels and black over light ones; the reading under it shows the position and the color.
- A click, Return, Enter, or C copies the color and closes.
- The arrow keys move the crosshair one captured pixel, ten with Shift.
- Escape cancels.
The color is copied in the notation Settings chooses: HEX (“#3366FF”, the default), RGB (“rgb(51, 102, 255)”), HSL (“hsl(225, 100%, 60%)”), OKLCH (“oklch(57.3% 0.234 265.3)”), or Display P3 (“color(display-p3 0.25 0.395 0.964)”). HEX, RGB, and HSL are sRGB; OKLCH and Display P3 keep a wide-gamut color’s true value. Colors are the captured pixels, unchanged.
The color card
With Option, a click, Return, or C opens the color card instead. It shows the color in all five notations, each with its own copy button. Contrast… picks a second color and shows the pair’s WCAG 2 ratio and APCA value; Pin keeps the color on screen as a color pin. The card goes after 15 seconds left alone.
The magnifier
Settings › Capture › Magnifier chooses what screenshots and Annotate Area show at the pointer before an area is chosen:
- Magnified (the default): a 120 pt loupe below and right of the pointer, 15 captured pixels across at 8 pt each, with a faint grid and the center cell marked, so an edge can be put on the exact pixel.
- Actual Size: a lens centered on the pointer, Small (75 pt, the default), Medium (90 pt), or Large (120 pt), showing the screen at its own scale with no grid. The color reading under it is what C copies.
Pick Color, Capture Text, recording, and scrolling keep the magnified loupe whatever the setting.
Measure
Choose Measure in the menu bar menu. Point at something, and lines run from the pointer out to the nearest edge in each direction, each with its length (“120 pt”). Drag a box around content and, when you let go, it snaps to the content’s bounds; click to clear the box.
Snapping and edge tolerance
Settings › Tools has Measurement snapping (on at first) and Edge tolerance. With snapping off, boxes stay exactly as drawn, and the lines from the pointer still work. Hold Command when you release a drag to skip snapping once.
The tolerance says how big a change between neighboring pixels counts as an edge. Lower tolerance finds finer edges; higher tolerance ignores small color changes.
| Tolerance | Channel change allowed |
|---|---|
| Zero | 0 of 255 |
| Low | 7 of 255 |
| Medium (default) | 13 of 255 |
| High | 26 of 255 |
The choice is remembered and applies across displays. Selections above 250,000 physical pixels find their edges in the background and show “Finding edges…”.
Keys while measuring
| Key | What it does |
|---|---|
| T | Cycles the tolerance presets |
| + / − | Raises or lowers the tolerance |
| Tab | Switches between points (the default) and pixels |
| ⌘ on release | Keeps a box exactly as drawn, once |
| ⌘C | Copies the measurement and stays |
| Return | Copies the measurement and closes |
| C | Takes the color under the crosshair, as Pick Color does |
| Arrows | Move one pixel |
| Escape | Cancels |
Limits
Pixels can’t always tell a faint border from its shadow, so a few results differ by one physical pixel. On photographs and busy backgrounds, results depend on the content and the tolerance. Measure finds pixel edges; it doesn’t recognize objects.