A tool for designers to measure screen dimensions

What is Dimensions?
'Dimensions' is a Firefox add-on, designed for those needing to accurately measure webpage distances. It detects borders from the mouse point draw either up/down or right/left, working with multiple elements like videos, buttons, gifs, text, icons. It supports extraction of dimensions from dropped image mockups, offers keyboard shortcuts, and allows measurement of area boundaries. It's an open-source tool hosted on Github, welcoming pull requests.
Users: 1,555 ▼ -2
Rating: 4.47 (15)
Version: 2.1.1resigned1 (Last updated: 2024-04-25)
Creation date: 2016-12-21
Weekly download count: 44
Firefox on Android: Yes
Risk impact: Moderate risk impact
Risk likelihood: Moderate risk likelihood
Manifest version: 2
  • activeTab
  • <all_urls>
Size: 23.95K
Stats date:

Other platforms

Not available on Chrome
Not available on Edge
Want to check extension ranking and stats more quickly for other Firefox add-ons? Install Chrome-Stats extension to view Chrome-Stats data as you browse the Firefox Browser Add-ons.
Chrome-Stats extension

This extension measures the dimensions from your mouse pointer up/down and left/right until it hits a border. So if you want to measure distances between elements on a website this is perfect. It doesn't really work with images because there the colors change a lot pixel to pixel.

Images & HTML Elements

Measure between the following elements: images, input-fields, buttons, videos, gifs, text, icons. You can measure everything you see in the browser.


Your designer handed you mockups as PNGs or JPEGs? Just drop them into Chrome, activate Dimensions and start measuring.

Keyboard Shortcut

See more
User reviews
User reviews summary
These summaries are automatically generated weekly using AI based on recent user reviews. Firefox Browser Add-ons does not verify user reviews, so some user reviews may be inaccurate, spammy, or outdated.
  • Useful for measuring and creating web designs
  • Simple and easy to use
  • Works well with different Firefox versions
  • Hotkey functions not working properly
  • Questionable permissions needing access to data from all websites
  • Non-functional in older Firefox versions
Most mentioned
  • Measurement features
  • Issues with functionality
  • Concerns about data access permissions
Recent reviews
Fix this: 1) default and configured hotkey does not work; 2) turning off with the Esc button does not work.
by Kostia, 2023-09-20
View all user reviews
Risk impact

Dimensions may not be safe to use and it requires some risky permissions. Exercise caution when installing this add-on. Review carefully before installing.

Risk likelihood

Dimensions is probably trust-worthy. Prefer other publishers if available. Exercise caution when installing this add-on.

Upgrade to see risk analysis details