Calculator
What the Flexbox Generator does
Flexbox Generator: generates Status and Flexbox CSS from flex-direction, justify-content and align-items. Example: flex-direction row, justify-content flex-start and align-items stretch gives status CSS ready.
From flex-direction, justify-content, align-items and gap (px), this tool derives Status and Flexbox CSS. The result recalculates on every keystroke without a button press or a page reload.
It is mostly used by people inspecting an API response. Most of these tasks are one-liners in a terminal, but not when you are away from one.
Nothing is uploaded: useful when the text you are inspecting contains keys or customer records.
The method, a field-by-field reference and a worked example built from the defaults are all on this page.
What do the Flexbox Generator fields mean?
The Flexbox Generator uses 4 inputs. The form opens pre-filled, so the fastest way in is usually to overwrite the one field you actually care about.
| Field | What to enter | Default |
|---|---|---|
| flex-direction | choose from row, column, row-reverse or column-reverse | row |
| justify-content | choose from flex-start, center, space-between or space-around | flex-start |
| align-items | choose from stretch, center, flex-start or flex-end | stretch |
| gap (px) | optional | 16 |
How does the Flexbox Generator work?
Each output is derived from the inputs above in a single pass; there is no hidden state carried between runs, so the same inputs always give the same generated output.
The guard clauses run before the formula does, which is why mistakes surface next to the field.
Worked example
These are the values the Flexbox Generator loads by default, and the result it produces from them. These are the tool’s own default values and the result they produce, not an invented illustration.
| flex-direction | row |
|---|---|
| justify-content | flex-start |
| align-items | stretch |
| gap (px) | 16 |
| Status | CSS ready |
|---|---|
| Flexbox CSS | display: flex; flex-direction: row; justify-content: flex-start; align-items: stretch; gap: 16px; |
How to use it
- Pick a value for flex-direction: the options are row, column, row-reverse or column-reverse.
- Pick a value for justify-content: the options are flex-start, center, space-between or space-around.
- Pick a value for align-items: the options are stretch, center, flex-start or flex-end.
- Set gap (px).
- Type a value and the answer is already there by the time you stop.
- The panel reports Status and Flexbox CSS.
- Both Copy Link and Print capture the current state, so pick whichever suits how you file things.
What this tool does not do
- Output follows the common convention for this format; a specific toolchain may have its own house style.
- Processing happens in your browser, so extremely large inputs are bounded by available memory.
- Assumptions built into the method are stated above, but they are still assumptions.
- Confirm the units before you act on the output. The arithmetic is only as sound as what went in.
Frequently asked questions
flex-direction, justify-content, align-items and gap (px). That is the whole form. A starting value is in place for each, which means a single edit is enough to get a meaningful answer.
With the values loaded when the page opens, status comes out as CSS ready. It recalculates the moment an input changes, which makes comparing scenarios quick.
No. The parsing happens in your browser, so sensitive payloads never leave your machine.
It costs nothing, and there is no limit on repeat use.
Reliable for the case described. Where more than one convention exists, the method section says which one is used.