CSS Flexbox Playground
Visual controls for flex-direction, justify-content, align-items, flex-wrap, and gap — live preview with sample boxes.
How to use this tool
- 1Select values for flex-direction, justify-content, align-items, and flex-wrap from the dropdowns.
- 2Drag the Gap slider to set the spacing between items.
- 3Drag the Item count slider to add or remove sample boxes.
- 4Copy the generated CSS from the output panel.
About CSS Flexbox Playground
This flexbox playground exposes direction, justify, align, wrap, and gap with sample boxes so you can see layout changes live.
Flex mental models stick better with a sandbox than with docs alone. Copy the CSS when the preview matches the design.
Select values for flex-direction, justify-content, align-items, and flex-wrap from the dropdowns. Drag the Gap slider to set the spacing between items. Drag the Item count slider to add or remove sample boxes. Copy the generated CSS from the output panel. Processing stays in your browser.
Use it to prototype navs and toolbars. Nested flex contexts still surprise — verify in the real layout.
Flex-grow/shrink/basis interact. Gap support is broad but check ancient targets. Copy CSS into your stylesheet after experimenting.
Close the tab when you finish so sensitive input is not left in page memory.
Frequently asked questions
Different tools use different definitions and parsers, so small gaps are common. CSS Flexbox Playground applies browser-native parsers and encoders appropriate to the job with one consistent browser-side rule set. Hidden characters, stricter syntax, or a different tokenizer usually explain the mismatch. Reduce the input to a minimal sample, then add pieces back until the difference appears. Match the rule your destination actually enforces.
Treat the error as a signal that this environment is stricter or configured differently. Browser APIs reject malformed structures early instead of guessing. Convert to a boring intermediate when it helps—plain UTF-8 text, PNG, WAV, or an unlocked PDF—then retry. If the intermediate works, the original encoding was the problem. Keep that minimal sample for the next regression check.
Runtimes disagree even when feature names match. Locales, parser strictness, codec builds, and library versions differ between your browser and CI. Export the exact bytes from CSS Flexbox Playground, hash them, and compare in the pipeline. Align normalization steps so both systems see the same input. Use the browser result as a reference artifact, then make CI match it.
Desktop apps win on deep feature sets, batch farms, and specialized hardware paths. CSS Flexbox Playground wins on zero install, private local processing, and speed for the everyday job on this page. Choose desktop software for multi-hour editorial work or exotic edge formats. Choose this tool when you need a correct result quickly without uploading. Many people do a quick pass here first, then open the heavy suite only if an edge case demands it.
Prefer CSS Flexbox Playground whenever the input is personal, unpublished, customer-owned, or under NDA, because the core transform stays in your browser via browser-native parsers and encoders appropriate to the job. Cloud services can still help for formats your browser truly cannot decode, but you must trust their retention policy. Strip secrets before any upload. Privacy is usually the reason to stay local—not a longer marketing checklist.
Start from the best original input you still have. Change only what the destination requires. Prefer lossless intermediates when you must convert twice. Because the tool is local, iterate in small steps: tweak one setting, re-run, compare. Spot-check a short sample before batching anything important.
No account is required for normal use. The core css flexbox generator transform runs in your browser on your device using browser-native parsers and encoders appropriate to the job. You get on-screen output, a copy action, or a download without a mandatory ToolBrigade upload for that step. Keep your browser updated. A few lookup utilities may call public reference APIs for live fields only—they still do not need your private documents.
Lighter text, code, calculator, and many image jobs work on modern phones. Large video encodes and huge PDFs are happier on a plugged-in laptop with more RAM. Fully client-side flows can continue offline once scripts are cached; live lookups still need network. If a run seems stuck, try a smaller sample, free memory by closing tabs, and confirm the input is not truncated. Prove the path on a short fixture before blaming the algorithm.