Page Grid Ruler is a free browser add-on for Chrome developed by rynu.smith. It falls under the category of Browsers and is classified as an Add-ons & Tools. This handy extension allows users to draw a grid view, obtain page dimensions in pixel units, and draw a ruler.

With Page Grid Ruler, users can easily display a customizable grid view on any webpage. The grid size can be adjusted to suit individual preferences. Additionally, a reference box is available for easy alignment. The extension also offers a ruler that provides real-time measurements of width, height, start, and endpoint values.

Using Page Grid Ruler is simple. Just press the action button on any page, and the extension switches to grid mode. From there, users can draw a custom ruler and view the live measurements. To return to normal browsing mode, simply press the "Escape" key or click the action button again.

It's important to note that Page Grid Ruler only supports pixel units and does not provide accurate values in other units such as mm, cm, or inches. Converting pixel units to other measurements would require the PPI (pixel density or resolution of a computer screen) value.

To customize the grid size, users can right-click on the action button. Two menus will appear, allowing users to adjust the grid size and thickness according to their preferences.