CrossHair documentation

A menu-bar utility for picking pixels and laying out interfaces. Four overlays — crosshair, loupe, guides, measure — each one keystroke away. This page walks through how to use them.

Installation

CrossHair comes three ways. The download from bendansby.com/apps/crosshair is a standard .dmg — open it and drag CrossHair.app to your Applications folder. The Mac App Store version installs and updates the usual way. The Setapp version lives at setapp.com/apps/crosshair and installs through the Setapp client; no separate license key, no trial.

Requires macOS 14 Sonoma or later, on Apple Silicon or Intel. The direct-download build auto-updates via Sparkle; you can also check anytime via Preferences → Check for Updates…. The Mac App Store and Setapp builds update through their own channels. See License for the differences between the three.

Screen Recording

CrossHair asks for Screen Recording permission on first launch. It needs it for the loupe to magnify the pixels under your cursor, for the crosshair to read the background to stay legible, and for Measure to auto-fit its dimension lines to colour edges in the UI underneath.

Nothing is recorded, saved, or sent anywhere. CrossHair reads pixels live and forgets every frame the moment the next one arrives.

If you tap any overlay without the permission, CrossHair surfaces its own explainer window with a Grant Screen Recording button — not the bare macOS system prompt. You can also re-grant from System Settings → Privacy & Security → Screen Recording at any time.

CrossHair lives in the menu bar (the little crosshair glyph). Click it to open a menu with each overlay, Preferences, and Quit. You can hide the icon entirely in Preferences → Menu Bar → Show icon in menu bar — once it's hidden, re-open CrossHair from Finder to get back to Preferences.

The click action of the icon is configurable. By default a primary click opens the menu; you can switch it to summon one of the overlays directly (see Click action). A right-click always opens the menu so Preferences and Quit stay reachable.

Crosshair

Press ⌘⌥X for a fullscreen transparent overlay with a crosshair that follows your mouse. Esc dismisses.

The crosshair is drawn as a two-pass stroke — dark first, white on top, both at 55% — so it reads on any background. On a light surface the dark pass wins; on a dark surface the white pass wins; on a midtone background both are visible.

Arrow keys nudge the system cursor by one point per press, ten with . Useful for landing the cursor on a pixel exactly when the mouse is too sloppy.

Loupe

Press ⌘⌥L for a circular zoomed view of the screen pixels under your cursor. A hint pill below the glass lists the controls.

KeysAction
1 / 2Shrink / grow the loupe
/ or / +Zoom out / in
PToggle the pixel grid (one cell per source pixel)
GDrop a horizontal + vertical guide pair at the reticle
/ / / Walk the reticle one source pixel
EscDismiss

The reticle walks independently of the system cursor — arrow presses advance it one source pixel at a time inside the glass, even though the cursor (and the captured sample around it) stays put. The reticle eases back to centre the moment you move the mouse.

The pixel grid only draws when zoom is high enough that each cell stays readable (≥ 3pt per cell). Crank zoom up if you don't see the grid after pressing P.

Guides

Press ⌘⌥G for a transparent fullscreen overlay you can use to drop horizontal and vertical alignment lines anywhere on screen. Guides persist across launches.

A small HUD chip at the top of the screen offers:

ButtonAction
+ H / + VEnter placement mode, then click anywhere to drop the line
ClearDelete every guide (undoable)
ConfirmLock the overlay click-through so lines stay visible while every click goes to the app underneath

While the overlay is in edit mode:

Pressing ⌘⌥G again toggles between edit and lock modes. To dismiss the overlay entirely — without losing your guides — use Hide Guides from the menu bar or the × button on the HUD.

Drop guides from the loupe

While the loupe is up, press G to lay a horizontal + vertical guide pair right at the reticle. Pinpoint a pixel at magnification, then mark it in one keystroke. The guides shoot out from the reticle with the same laser-line flash as the Guides overlay's HUD.

Measure

Press ⌘⌥M for a transparent overlay that lays measurement lines over anything on screen.

Drag for a free measurement

Drag out a line — the length is shown live in points. Hover the line or its pill to flip to pixels. Drag the end caps to adjust, drag the line to reposition, arrow keys nudge the selected handle, removes.

Click for an auto-fit cross

Click once in a flat-colour region and Measure drops an auto-fit cross that snaps to the full width and height of that colour band — perfect for measuring a button, a sidebar, a padding gap. A faint dashed preview shows what a click will produce while you hover.

HUD

ButtonAction
ClearDelete every measurement (undoable)
ConfirmLock the overlay click-through so measurements stay on screen while you keep working

Same keyboard polish as Guides — C clears, Return confirms, Esc dismisses, ⌘Z / ⌘⇧Z undo / redo.

Measurements are transient — they live only while the overlay is up, and dismissing the overlay clears them. (Guides, by contrast, persist across launches.)

Shortcuts

Preferences → Keyboard Shortcuts lets you rebind every overlay's hotkey. Each shortcut needs at least one modifier ( ). A small Reset chip appears next to any row that's been changed from the default.

You can also clear a shortcut entirely to disable it — a valid state for menu-bar-only use, or if you only want one overlay reachable from the icon.

Click action

Preferences → Menu Bar → Clicking the icon sets what a primary click of the menu-bar icon does:

Right-click the icon always opens the menu, so Preferences and Quit stay reachable regardless of the click action you pick.

Open at login

Preferences → General → Open at login launches CrossHair quietly when you log in. The system's own registration is the source of truth — you can also flip this from System Settings → General → Login Items without going through CrossHair.

Keyboard shortcuts

KeysAction
⌘⌥XShow / hide the crosshair
⌘⌥LShow / hide the loupe
⌘⌥GShow / cycle the guides overlay
⌘⌥MShow / cycle Measure
EscDismiss the active overlay
/ / / Nudge cursor (crosshair) or reticle (loupe) one point / pixel
-arrowNudge ten at a time
1 / 2Shrink / grow the loupe
/ or / +Loupe zoom out / in
PToggle the loupe pixel grid
GDrop guides at the loupe reticle
CClear (Guides / Measure edit mode)
ReturnConfirm (Guides / Measure edit mode)
⌘Z / ⌘⇧ZUndo / Redo (Guides / Measure)
Delete the selected guide / measurement

Accessibility

CrossHair honours macOS accessibility settings:

Languages

CrossHair is localized into English, Deutsch, Español, Français, Italiano, 日本語, 한국어, Português (Brasil), Українська, Русский, and 简体中文. It picks the right language automatically based on your System Settings → General → Language & Region preferences.

To pin CrossHair to a specific language without changing system preferences, open System Settings → General → Language & Region → Applications, click the + button, and pick CrossHair.

License

CrossHair ships through three channels — pick the one that fits how you like to pay for software: