What does this tool do?
The CSS Variables Generator turns design values like brand colors, radii, and shadows into a tidy block of CSS custom properties. You enter a name, value, and optional comment per row, and choose which selector (such as :root) they're defined on. It's ideal for front-end developers building a design system or setting up theming.
How to use it
- Adjust the values and options.
- See the result in the live preview.
- Copy the generated CSS/code into your project.
How it works
Add variables to the table, type their names with the '--' prefix handled for you, and set their values. When a value is a valid hex color (for example #3b82f6), a color picker appears next to it so you can tweak the shade visually, but you can also enter any CSS value like '8px' or '0 1px 3px rgba(0,0,0,0.1)'. Rows where you add a comment render as a '/* ... */' note in the output. The generator gathers everything under your chosen selector and makes it copyable in one click.
Why use variables for a design system
Custom properties centralize your color palette, spacing, and shadows in one place, so changing a single value updates every component that uses it. This makes dark/light theme switches, rebrands, and consistent spacing scales much easier. Variables are called with 'var(--primary)' and, unlike SASS variables, can be changed at runtime in the browser, which enables dynamic theming with JavaScript.
Frequently asked questions
Why do variable names start with '--'?
CSS custom properties must begin with two dashes by language rule, for example '--primary'. The tool adds this prefix for you, so you only type the name part, and spaces in names are converted to dashes automatically.
Can I use a selector other than :root?
Yes. Type any selector in the selector field, such as '.theme-dark' or '.card'. That's useful when you want to scope variables to a specific component or theme class, whereas :root makes them global to the whole document.
Can I enter values that aren't colors?
Yes. The color picker only appears when a value is a valid hex color, but you can manually type any valid CSS value, such as a size, radius, shadow, or even a 'clamp()' expression.
Is CSS Variables Generator free?
Yes. CSS Variables Generator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. CSS Variables Generator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.