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To download Euclid from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.


By Nicholas Jensen

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Euclid is a screen ruler app for the perfectionist developer/designer. Set a global hotkey to trigger Euclid and turn your mouse into crosshairs. Click and drag to quickly measure anything on your screen *without* accidentally taking a screenshot.


Global Hot Key. Trigger Euclid at any time with Command + Shift + 2, this hotkey can be changed in Preferences.

Crosshairs. When Euclid is triggered your mouse will be turned into fullscreen crosshairs. Use these to make sure that anything you're working on lines up perfectly. The color of the crosshairs can be changed in Preferences.

Pixel or Point Measuring. Click and drag to quickly and accurately measure anything that is on your screen. Let go of your mouse or hit Escape to dismiss Euclid so you can get back to work!

Arrow keys can be used to move crosshairs and measurements by 1 pt or 1 px for increased precision.

Zoom Window. For the true perfectionist. Euclid will show you a 10x zoomed area, when activated, so you can see precisely where your cursor is. This feature can be turned off in preferences.

Copy to Clipboard. A list of recent measurements can be found in the status bar menu, select one to copy it. You can also automatically copy the last measurement to your clipboard in Preferences.

Supports Retina display. Supports Multiple displays.

For support & feature requests, email

What's New in Version 1.3

• Measure in Pixels or Points (Preference).
• Recent Measurements in status bar menu. Select one to copy.
• Automatically copy last measurement to your clipboard (Preference).
• Clicking can now toggle between measuring and guides (Preference).
• Show Euclid from the status bar menu.
• More accurate zoom window.
• Better multi-screen support.
• New status bar icon.


Screenshot 1
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Customer Reviews

Great measurement tool

Have to say this is a great tool to have. For a long time I’ve had to use a screenshot in order to get measurements, which worked fine. Only issue I’m finding is that Euclid gets the incorrect measurement when used on Retina screens. For example, Euclid will get a measurement of 440px whereas taking a screenshot would get about 220px. Not sure if this is intentional since I know if I took a screenshot of that 220px area, it would actually turn out to be a 440px image on a normal screen.

Limited usefulness

I bought the app hoping that the full-screen crosshairs could just be left on and that normal interaction with my software would be possible. Unfortunately, this is not the case. When the crosshairs are invoked, you can perform a lasso measurement, then the mode is exited. I did contact the developer and am hoping this general cursor use can be implemented in a future version. (If that is the case, I will update my review and rating).

Nothing Better

As a web develoeper this little tool has been amazing. The zoom feature is great and this is hands down best tool to measure anything on your screen. Please keep up the good work. Thank You

View in Mac App Store
  • $1.99
  • Category: Developer Tools
  • Updated:
  • Version: 1.3
  • Size: 0.6 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.8 or later, 64-bit processor

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