CSS Flexbox Generator

Experiment with flex-direction, justify-content, align-items, wrap and gap with a live preview, then copy the CSS. Runs in your browser.

How to use CSS Flexbox Generator: Open CSS Flexbox Generator — it runs entirely in your browser with no setup. Paste or type your input into the text area, or upload a file where supported. Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server. Everything runs inside your browser, so your data never leaves your device.

flexDirectionjustifyContentalignItemsflexWrapGap (8px)Items (4)

display: flex;
flex-direction: row;
justify-content: flex-start;
align-items: stretch;
flex-wrap: nowrap;
gap: 8px;

Experiment with flex-direction, justify-content, align-items, wrap and gap with a live preview, then copy the CSS. Runs in your browser. CSS Flexbox Generator is a free, browser-based tool in the Filevane developer tools collection — there is nothing to install, no account to create and no watermark on your results. It works on desktop, tablet and mobile, and because the work happens on your own device it stays fast even with large inputs.

How to use CSS Flexbox Generator

Open CSS Flexbox Generator — it runs entirely in your browser with no setup.
Paste or type your input into the text area, or upload a file where supported.
Set any options you need. The result appears in the output panel — there is no upload step and no waiting on a server.
Review the output instantly; large inputs are handled locally without lag.
Copy the result to your clipboard or download it. Your data never leaves the page.

Why use CSS Flexbox Generator?

100% free with no limits, no sign-up and no watermarks.
Private by design — your data are processed in your browser and never uploaded to a server.
Fast and lightweight, with instant results even on a phone or a slow connection.
Works everywhere — any modern browser on Windows, macOS, Linux, Android or iOS.
Part of a full developer tools suite, so related flexbox tasks are one click away.

What people use CSS Flexbox Generator for

Working out the right combination of justify-content and align-items for a layout.
Building a navigation bar or a card row with even spacing.
Understanding why a flex item is not sizing the way you expect.

CSS Flexbox Generator: limits and things worth knowing

justify-content works along the main axis and align-items across it, and the main axis flips when flex-direction is column. Almost every flexbox confusion traces back to this.
The flex shorthand's third value is flex-basis, and it takes precedence over width. An item with an unexpected size usually has a flex-basis you did not mean to set.
flex: 1 expands to 1 1 0%, which sizes items by available space. flex: auto expands to 1 1 auto, which sizes them by content first — the difference is why one row distributes evenly and another does not.
gap works in flexbox in all current browsers and replaces the old margin-on-every-child-except-the-last pattern.

Is it private and secure?

Your privacy is built in. CSS Flexbox Generator runs completely on your device, so whatever you enter stays in your browser and is never transmitted, logged or stored on any server.

Network activity: none. Nothing is sent and nothing is fetched. This tool makes no network request at all once the page has loaded — which is why it keeps working if your connection drops.

You do not have to take that on trust — our privacy proof page publishes the Content-Security-Policy that enforces it, lists every third party it permits, and shows how to verify the whole claim yourself.

Learn more

Is It Safe to Paste Production Data Into Online Tools? — JWTs, API responses and env files get pasted into online formatters every day. Here's what actually happens to that data and how to check before you paste.

See all free developer tools or browse the full tool catalogue.