Web Tools

CSS Builder

The CSS Builder creates CSS classes from validated building blocks, allowed properties and checked values. Select a building block, adjust the available properties and add the finished class to the output.

CSS classes from safe building blocks

This tool is not a free-form CSS editor. It does not accept unchecked CSS directives, external resources or arbitrary selectors. Generated classes are built only from prepared blocks and allowed input values.

This makes the builder useful for quick layout experiments, small web projects, UI prototypes and technical documentation. The preview is an approximation; the final appearance always depends on the existing CSS of the target website.

Experiment area

Select building block

Element / building block After selecting a block, only matching properties are shown. Class name The dot is added automatically. Letters, numbers, hyphens and underscores are allowed.

Properties

All properties are loaded from an allowlist. Unsupported CSS functions such as @import, url() or external resources are not generated.

Live preview

Ready

CSS output

Generated CSS classes

Added classes

Class names that have already been added cannot be added again. This prevents unintended duplicate rules.

Safety and limitations

The CSS Builder generates CSS from checked building blocks and validated values.
The generated code should be tested in your own layout before production use.
External resources, @import, url() and free-form CSS input are intentionally not supported.
The preview is only an approximation; the actual appearance depends on the existing website CSS.
Before integrating the code into production projects, check whether existing classes may be overridden.