CSS Grid vs Flexbox: When to Use Which?

For years, CSS layout was a nightmare of floats and positioning hacks. Then came Flexbox, and shortly after, CSS Grid. Now, developers are spoiled for choice, but often confused: which one should I use?

1-Dimensional vs 2-Dimensional

The simplest rule of thumb is this: Flexbox is for one-dimensional layouts (a row OR a column). CSS Grid is for two-dimensional layouts (rows AND columns).

Content-First vs Layout-First

Flexbox works from the content out. You let the content dictate how much space an item takes. Grid works from the layout in. You define the grid structure first, and then place items into it.

The best way to understand the difference is to code it. Open a Code Editor and try building the same component using both. You will quickly feel which approach is more natural for the task.

Conclusion

They are not mutually exclusive. In fact, they work brilliantly together. Use Grid for the main page structure and Flexbox for the alignment of items inside those grid cells.