https://drafts.csswg.org/css-align/#distribution-values | Alignment | Fallback | | - | - | | `space-between` | `flex-start` | | `space-around` | `safe center` | | `space-evenly` | `safe center` | As per https://drafts.csswg.org/css-align/#valdef-overflow-position-safe, `safe center` will basically behave as `start`, which differs from the `flex-start` of `space-between`. Blink seems to treat all of them as `flex-start` ```html <!DOCTYPE html> <style> .flex { display: inline-flex; flex-wrap: wrap-reverse; flex-direction: row-reverse; height: 100px; width: 100px; border: solid; margin: 30px; } .flex::before { content: ""; height:125%; width: 125%; flex-shrink: 0; z-index: -1; background: cyan; } </style> <div class="flex" style="place-content: space-between"></div> <div class="flex" style="place-content: space-around"></div> <div class="flex" style="place-content: space-evenly"></div> ``` 