A question that keeps turning up in forums and on Discord: should I use Grid or Flexbox? The short answer is that both have their place. But let me break it down, because I was thoroughly confused about this myself for a while.
The underlying principle is actually simple
Flexbox works in one dimension. Either horizontal or vertical, but not both at once. Sure, you can use flex-wrap and let elements break onto the next line. That works. But you never really have control over both axes at the same time.
Grid, on the other hand, is two-dimensional. Rows and columns. You define a raster and place elements inside it. That sounds like more effort up front, and sometimes it is. But for certain layouts there simply is no better answer.
Where Flexbox shines
Navigation. Toolbars. Anything that sits in a row and needs to divide up the available space. The classic example:
.nav {
display: flex;
justify-content: space-between;
align-items: center;
}
Three lines of CSS and the navigation looks reasonable on any screen. Try that with Grid — it works, but it feels like using a sledgehammer to crack a nut.
Card layouts where the cards simply sit next to each other and wrap when space runs out are also faster to build with Flexbox. flex-wrap: wrap and a min-width on the children, done.
Where Grid pulls ahead
As soon as a layout gets more complex. Sidebar plus content plus a footer that spans the whole width? Grid. An image gallery with differently sized elements? Grid with auto-fill and minmax().
.layout {
display: grid;
grid-template-columns: 250px 1fr;
grid-template-rows: auto 1fr auto;
gap: 1rem;
}
What convinced me most: grid-template-areas. You name regions and move them around like building blocks. That is about as close to visual design as you get while still writing code.
The most common mistake
People try to build entire page layouts with Flexbox. Yes, it is possible. No, it is not a good idea. You end up with nested flex containers, and by the third breakpoint you have lost track of what is doing what.
The other way round: using Grid for a simple button group is overkill. Not wrong, just unnecessarily complex.
How I work now
I usually start with one question: do I need control in two directions? If yes, Grid. Is it only about distributing elements along one axis? Flexbox.
And honestly, in practice I mix the two constantly. Outer layout in Grid, individual components inside it in Flexbox. They do not exclude each other at all.
If you are unsure: just start, and rebuild when you hit a problem. It is CSS either way — the browser will not complain.