Pigment CSS, project status

[oliviertassinari]

We haven't communicated enough about the state of Pigment CSS, so we're using this GitHub issue as a single place to keep the community informed about the latest state of this library.

History:

June 2024

Talk at React Conf on why Pigment CSS is needed https://www.youtube.com/watch?v=n_0cz-JwlsU.

January 2025

The project is facing two main issues:

1. It slows down the build too much
2. It has too many bugs

This is after 14+ months of work on it; we were 1.5 FTE.

To fix this, it felt we would need to rethink the project's technical design from scratch.
So, to make it work, we would need to double down on the effort on it (move from one engineer on it to a team of 3 FTE). At the same time, we have other projects that we are underinvesting in to succeed.
So we pause work on Pigment CSS, we first want to get the right focus on Base UI to make it succeed.

On the upsides of delaying, the space of bundlers is standardizing; we will have fewer targets to support, and AI will be stronger at this type of work

January 2026

Same message https://mui.com/blog/2026-and-beyond/#pigment-css

June 2026

Will we resume the work on Pigment CSS? Current state:

I would love to, but with AI, there might not be any need for it now. Tailwind CSS and CSS Modules are progressively taking over the whole space. If you are relying on prompting agents, do you still need to care about the pains listed in:

• https://www.youtube.com/watch?v=n_0cz-JwlsU
• or https://mui-org.notion.site/pigment-css-Why-does-it-need-to-exist-25205c31c8564e0daee6f79523de9b5c?source=copy_link

?

We are also still heavily focused on components right now, under Base UI, MUI; we don't have a lot of bandwidth for a reset of this project.