98.css vs Primer CSS
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A CSS stylesheet that makes plain HTML look like Windows 98 interface elements.
Open source · MIT
GitHub's CSS design system, distributed as Sass styles for building GitHub-style interfaces.
The short answer
Choose 98.css if you need…
- Web developers making a retro or nostalgic website
- Designers who want Windows 98-style mockups in HTML
- Developers who want a stylesheet with no JavaScript dependency
- Anyone building a novelty or joke app in an old Windows look
Choose Primer CSS if you need…
- Developers who want to match GitHub's visual style in an existing web project
- Teams already using Sass who want ready-made UI styles and utility classes
- Maintainers of existing products that already depend on @primer/css
Side-by-side
| 98.css | Primer CSS | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 11.6k | 13.1k |
| Setup difficulty | Beginner | Intermediate |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | CSS | SCSS |
| Last code update | 14 months ago | 5 days ago |
What each one is
98.css
98.css is a CSS file that styles standard HTML elements so they resemble the classic Windows 98 user interface. It contains no JavaScript, so it can be used alongside any frontend framework. People use it to build retro-styled windows, dialogs, and buttons for websites or design projects.
Primer CSS
Primer CSS is the CSS implementation of GitHub's Primer Design System. It provides Sass (SCSS) source files that supply GitHub's styles, components and utility classes, which developers can import into their own projects. The README says the project is now in maintenance-only mode, and points people to primer/react or primer/view_components for newer patterns.
Best for
98.css
- Web developers making a retro or nostalgic website
- Designers who want Windows 98-style mockups in HTML
- Developers who want a stylesheet with no JavaScript dependency
- Anyone building a novelty or joke app in an old Windows look
Primer CSS
- Developers who want to match GitHub's visual style in an existing web project
- Teams already using Sass who want ready-made UI styles and utility classes
- Maintainers of existing products that already depend on @primer/css
Strengths
98.css
- Single CSS file with no JavaScript, so it fits into any frontend stack
- Available via unpkg, npm, and GitHub releases
- MIT licensed
Primer CSS
- Backed by GitHub and published on npm under the MIT license
- Documentation site is linked from the README and covers getting started, components and theme
- Modular imports let you include only the parts you need
Not ideal for
98.css
- Projects needing a modern, general-purpose UI kit, since it only mimics the Windows 98 look
- Teams that need accessibility guarantees, since the README does not discuss accessibility
Primer CSS
- New projects that need full component patterns: the README directs these to primer/react or primer/view_components, since this project is in KTLO (keep-the-lights-on) mode
- People who want a no-build, plain-CSS drop-in: the README says the source is Sass using SCSS syntax, so a build step is expected
Trade-offs
98.css
- Only covers the Windows 98 visual style, not general layout or components beyond what it styles
- The README is brief on component details and points to an external documentation site for those
Primer CSS
- The README states the project is in KTLO (keep-the-lights-on) mode, so new development is limited
- Requires a Sass toolchain and knowledge of load paths
- The README is brief on specifics, so details such as browser support and configuration are not covered here
Getting started
Primer CSS
Install the package
npm install --save @primer/cssFrequently asked questions
What is the difference between 98.css and Primer CSS?
98.css: A CSS stylesheet that makes plain HTML look like Windows 98 interface elements. Primer CSS: GitHub's CSS design system, distributed as Sass styles for building GitHub-style interfaces. 98.css suits web developers making a retro or nostalgic website, while Primer CSS suits developers who want to match github's visual style in an existing web project.
Are 98.css and Primer CSS free?
98.css: Free and open source. Primer CSS: Free and open source.
Which is easier to set up, 98.css or Primer CSS?
98.css is easier to get started with (rated beginner); Primer CSS is rated intermediate and usually needs more setup.
Is 98.css or Primer CSS more popular?
Primer CSS has more GitHub stars (13.1k) than 98.css (11.6k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to 98.css and Primer CSS?
Other options people compare them with include daisyUI, HyperUI, Bootstrap, Tailwind CSS, Bulma.
Keep comparing
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.