Developer: Nicholas Jensen

Current Version: 1.3

Last Updated: 3 years ago

Download Size: 596.6 KB - Download


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 [email protected]


Release Notes:

• 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.


Most Helpful Reviews

Version 1.0
Review by displaycopy

Waaay better than using the screen grab tool - I'm constantly using my screen grab tool to take quick pixel measurements, with the unfortunate side effect of accidentally taking lots of screenshots. This app basically solves that problem, and does so pretty much perfectly.

Found helpful by 2 out of 2 people

More Reviews for Current Version

Version 1.3
Review by Chatlanian

Awesome! - Perfect. At last. Simple, streight forward tool. Click, drag, release - get your dimentions copied to clipboard. Just what I was looking for. Even works on retinan. And a bonus - with dark menu bar the menu bar icon is white. (seem to be a big problem for many spare-bedroom-developerz) MacBook Pro Retina. OSX Sierra 10.12 (16A323)

Found helpful by 1 out of 1 people
Version 1.3
Review by lindes

Nice... and not. - I'll start with the pros: 1. I love that it can be triggered off of Cmd+Shift+2 -- fits right in to the keystrokes I've known for years for screenshots (Cmd+Shift+3 for full screen and Cmd+Shift+4 for selecting a region or a window). 2. Measurements reported for pixels appear to be accurate. The cons: 1. The measurements for a "point" don't seem like anything I'd expect them to be (at least on MacBook Pro (Retina, 15-inch, Mid 2015)). They seem to map to approximately 1/110th of an inch (0.0090909...), based on Preview showing "actual size" a Letter-size (8.5x11 inches) PDF (which matches on the screen almost identically with an actual piece of paper held up to it), by measuring the whole width and dividing by 8.5. But if you look on the Wikipedia page for "Points (typography)", none of the normal standards appear to be 110 points per inch. And certainly this is not the definition I'm most accustomed to, from the print industry, of 72 points per inch (i.e. one point is 1/72nd of an inch). 2. It seems to be impossible (again, on the same machine) to measure at single-pixel increments. Even using "Mouse Keys" (from the Accessibility settings), I get 2 pixels for each keypress. This may be a MacOS thing that's inherent - cropping in Preview seems to _sort of_ do this, but it's a bit worse here. 3. Only measurement modes are pixels and (whatever) points (are). It would be really nice to also have inches and mm or cm. Ideally, it might show all 4 of the measurements on the screen simultaneously, as well. Anyway, it mostly does what it said it would do (I was not expecting points to do what they did), and what it does it does fairly well. Just a lot that could be better.

Found helpful by 1 out of 1 people
Version 1.3
Review by ForeverIDy

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

Found helpful by 0 out of 0 people
Version 1.3
Review by B'bba

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).

Found helpful by 0 out of 0 people
Version 1.3
Review by Drevend

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.

Found helpful by 0 out of 0 people