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CSS Box Model Visualizer

Q: What is box-sizing: border-box?

With box-sizing: border-box, the width and height you set include padding and border. So a 200px element stays 200px even with padding. Without it (content-box), padding and border add to the total size.

Interactively explore margin, border, padding, and content with a live diagram.

Margin

Border

Padding

Content

Margin (px)

Top

Right

Bottom

Left

Border (px)

Width (all sides)

Padding (px)

Top

Right

Bottom

Left

Content (px)

Width

Height

About CSS Box Model Visualizer

CSS Box Model Visualizer is a free visual design tool that helps front-end developers and designers interactively explore margin, border, padding, and content with a live diagram with a live preview. Instead of writing CSS by hand and refreshing your browser repeatedly, use this interactive tool to experiment with values and copy the generated code directly into your project.

How to Use

Adjust the visual controls Use sliders, color pickers, and dropdowns to customize the design properties. The preview updates in real time.

Fine-tune the result Experiment with different values until the design looks exactly the way you want it.

Copy the CSS code Click the Copy button to copy the generated CSS code. It's production-ready and includes vendor prefixes where needed.

Paste into your project Add the copied CSS to your stylesheet. The code works in all modern browsers without modification.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use CSS Box Model Visualizer?

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Visual Live Preview See your changes in real time as you adjust values. No more guessing what CSS properties will look like — experiment visually and copy the code.

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Production-Ready CSS The generated code is clean, optimized, and ready to paste directly into your stylesheet. Includes vendor prefixes where needed for cross-browser support.

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Faster Than Hand-Coding What takes 10 minutes of CSS trial-and-error takes 10 seconds with CSS Box Model Visualizer. Adjust sliders and dropdowns instead of editing numbers in code.

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Learn CSS Visually Perfect for CSS beginners who want to understand how properties affect visual output. Experiment with values and see the relationship between code and design.

Frequently Asked Questions

With box-sizing: border-box, the width and height you set include padding and border. So a 200px element stays 200px even with padding. Without it (content-box), padding and border add to the total size.

Margins are outside the element's boundary. They create space between elements but are not part of the element's computed size. The element's total rendered area = content + padding + border.

Yes! Click any layer in the diagram (margin, border, padding, or content) to highlight it and see that layer emphasized.