OSX Resizer is a free Chrome extension developed by dane.macaulay that allows users on Mac to view websites in a window smaller than 400 pixels. This handy tool is specifically designed for Chrome users who want to view web pages at the same resolution as a smartphone, such as 320 pixels.

Chrome users on a Mac often face a limitation where they are unable to shrink the browser window below 400 pixels. However, this extension bypasses this constraint by simply opening the current tab in a pop-up window. With just eight lines of code, OSX Resizer provides a simple and effective solution for Mac users who need to view websites in a smaller window size.

With OSX Resizer, Mac users can now easily simulate the mobile browsing experience without having to switch devices or resize their browser windows manually. This extension is a valuable tool for web developers, designers, and anyone who needs to test their website's responsiveness on different screen sizes.

Overall, OSX Resizer is a straightforward and efficient Chrome extension that fulfills its purpose of allowing Mac users to view websites in a window smaller than 400 pixels. It's a must-have tool for anyone who wants to test website responsiveness or simply experience mobile browsing on their Mac.