CSS Grid Layout is a two-dimensional layout system for the web. It allows you to arrange content into rows and columns simultaneously, making it far more powerful than older one-dimensional methods like floats or flexbox. With CSS Grid, you define a grid container with display: grid, specify your column and row tracks using grid-template-columns and grid-template-rows, and place child elements precisely within the grid. It's supported in all modern browsers and is ideal for complex page layouts, card grids, and responsive design patterns.

Start by selecting a preset template or customize your grid manually. Add/remove columns and rows using the toolbar buttons. Drag the dividers between columns or rows to resize them visually. Click any grid item to select it, then adjust its column span, row span, and position in the Properties panel. You can also drag items to reposition them and drag the corner handle to resize. The CSS code updates in real-time — simply copy it and paste into your project.

Column widths use fr (fractional units) by default, which distribute available space proportionally. For example, 1fr 2fr 1fr means the middle column gets twice the space of the side columns. Row heights use pixel (px) values for precise control. When you drag column dividers, the fr ratios update automatically. The gap between grid cells is set in pixels. All these values can be adjusted in real-time, and the generated CSS reflects exactly what you see.

Absolutely! CSS Grid and Flexbox complement each other perfectly. Use CSS Grid for the overall page layout (header, sidebar, main content, footer) and Flexbox for component-level alignment within grid items (like aligning buttons in a card or centering text in a header). Grid handles two-dimensional layouts best, while Flexbox excels at one-dimensional alignment. Many modern websites use both — Grid for the macro layout and Flexbox for micro layouts inside grid cells.

CSS Grid becomes responsive when combined with functions like repeat(), auto-fit, auto-fill, and minmax(). For example, grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)) creates a responsive grid that automatically adjusts the number of columns based on available space — no media queries needed. You can also use media queries to redefine your grid template at different breakpoints. The CSS generated by this tool gives you a solid starting point that you can enhance with responsive techniques.

CSS Grid is supported in all modern browsers, including Chrome (57+), Firefox (52+), Safari (10.1+), and Edge (16+). According to Can I Use, global support exceeds 97%. Even Internet Explorer 10 and 11 have partial support with the -ms- prefix. For production websites targeting modern audiences, CSS Grid is safe to use without fallbacks. If you need to support very old browsers, consider providing a flexbox-based fallback using @supports queries.