Flexbox Generator
Open Flexbox Generator on Happytails.ai. This view has the same page content and links, with explicit tool capabilities. Read the processing notes before using a tool.
Tool capabilities
{
"id": "css-flexbox",
"category": "design-tools",
"built": true,
"requirements": "Responsive interactive preview with generated CSS and minimal HTML.",
"implementation": {
"fields": [
{
"key": "direction",
"label": "Direction",
"value": "row",
"type": "select",
"values": [
"row",
"column",
"row-reverse",
"column-reverse"
]
},
{
"key": "justify",
"label": "Justify",
"value": "flex-start",
"type": "select",
"values": [
"flex-start",
"center",
"space-between",
"space-around",
"flex-end"
]
},
{
"key": "align",
"label": "Align",
"value": "stretch",
"type": "select",
"values": [
"stretch",
"center",
"flex-start",
"flex-end"
]
},
{
"key": "wrap",
"label": "Wrap",
"value": "wrap",
"type": "select",
"values": [
"wrap",
"nowrap"
]
},
{
"key": "gap",
"label": "Gap (px)",
"value": 16,
"type": "number"
}
],
"input": false,
"experience": {
"automatic": true,
"single": false,
"inputMaxLength": 1000000,
"inputMode": "text",
"label": "CSS",
"placeholder": "a { color: #3366cc; }",
"help": "Paste CSS rules, including their selectors. Results update as you type. Up to 1,000,000 characters.",
"helpParts": [
"Paste CSS rules, including their selectors.",
"Results update as you type.",
"Up to 1,000,000 characters."
],
"action": null
},
"mode": "automatic",
"interactive": false
},
"execution": "POST /api/v1/tools/css-flexbox/run",
"api": {
"id": "css-flexbox",
"name": "CSS flexbox",
"category": "design-tools",
"description": "Responsive interactive preview with generated CSS and minimal HTML.",
"notes": "",
"human_path": "/en/design-tools/css-flexbox/",
"method": "POST",
"endpoint": "/api/v1/tools/css-flexbox/run",
"schema_url": "/api/v1/tools/css-flexbox",
"input_schema": {
"type": "object",
"additionalProperties": false,
"properties": {
"input": {
"type": "string",
"maxLength": 1000000,
"default": "",
"description": "Plain text input. File tools use files instead unless otherwise documented."
},
"options": {
"type": "object",
"additionalProperties": false,
"properties": {
"direction": {
"type": "string",
"description": "Direction",
"default": "row",
"enum": [
"row",
"column",
"row-reverse",
"column-reverse"
]
},
"justify": {
"type": "string",
"description": "Justify",
"default": "flex-start",
"enum": [
"flex-start",
"center",
"space-between",
"space-around",
"flex-end"
]
},
"align": {
"type": "string",
"description": "Align",
"default": "stretch",
"enum": [
"stretch",
"center",
"flex-start",
"flex-end"
]
},
"wrap": {
"type": "string",
"description": "Wrap",
"default": "wrap",
"enum": [
"wrap",
"nowrap"
]
},
"gap": {
"type": "number",
"description": "Gap (px)",
"default": 16.0
}
}
}
}
},
"output_schema": {
"type": "object",
"required": [
"tool",
"result"
],
"properties": {
"tool": {
"type": "string"
},
"result": {
"type": "object",
"required": [
"text",
"files"
],
"properties": {
"text": {
"type": [
"string",
"null"
]
},
"data": {
"description": "Parsed JSON when the textual result is JSON."
},
"name": {
"type": "string"
},
"mime": {
"type": "string"
},
"files": {
"type": "array",
"items": {
"type": "object",
"required": [
"name",
"mime",
"bytes",
"base64"
],
"properties": {
"name": {
"type": "string"
},
"mime": {
"type": "string"
},
"bytes": {
"type": "integer"
},
"base64": {
"type": "string",
"contentEncoding": "base64"
}
}
}
}
}
}
}
},
"processing": "Server; same transformation code as browser tools",
"limits": {
"request_bytes": 8388608,
"input_characters": 1000000,
"files_bytes": 5242880,
"max_files": 0,
"timeout_seconds": 12
}
},
"agent_processing": "Server; same transformation code as browser tools",
"browser_agent": {
"supported": true,
"name": "run_current_tool",
"discovery": "WebMCP on the human page in a supporting browser",
"verification": "See audit/API-AUDIT.md; availability is not verification"
}
}Page guide
Create CSS for a flexible row or column layout.
How to use CSS flexbox
- Enter the values you want to calculate and choose the relevant units or settings.
- The result updates as you type. Adjust the available settings if needed.
- Review the result, then use Copy result or a download link when available.
Useful next steps
Working with css flexbox
Design utilities help translate colors, dimensions and layout values into reusable settings. A color representation or size calculation is only useful when its units and intended display context are clear.
Common questions
Are colors identical on every display?
No. Display calibration, color management and viewing conditions can change appearance. Numeric color conversion does not control those conditions.
Does a computed contrast ratio describe the whole design?
A ratio compares specified foreground and background colors. Transparency, images, font size and other visual choices can change the actual reading experience.
Continue your workflow: CSS box shadow, CSS grid.