Spectrum UI has 1,023 stars, 193 items in its registry index, and 29 components published here. Its own description says it draws on other registries, which is worth reading literally: some of what it offers you may already have.
What the numbers say about how people use it is more interesting. Three of its five most-taken components here are footers.
The footers
Footer section is the most-taken component in the set by a distance, a plain footer with a theme toggle. Stacked Circular Footer and Large Name Footer are the two variants, the second being the oversized-wordmark treatment.
That concentration is a real signal about the component rather than the registry. A footer is the last thing anyone builds, it is nearly always the same six link columns, and taking a finished one is an easy decision. The footer guide has the checks that still apply: real links rather than buttons, a working theme toggle, and no navigation that exists only there.
The rest of the set
Multistep Form is the second most-taken and the most demanding thing here, since a multi-step form owns validation timing, a back button that does not lose state, and a step indicator that says where you are, per the form guide and the stepper guide.
Status Badge, Profile Dropdown, Navbars, Kanban Board and Login Card cover the product surfaces, each with a guide of its own: badges, dropdowns, navbars, kanban and sign-in.
Event Calendar, Dual Range Slider and Multiple Selector are the harder inputs, which is where a general registry earns its place: those take a day each to write properly.
What a 193-item registry is for
It is a general set, which puts it in the middle layer of the layered setup: primitives underneath, one general registry for product surfaces, and individual components for the parts meant to stand out.
The check that comes with a set assembled from other sets is duplication. If you already have a card from one registry, taking another one gives you two components with the same job and different tokens, which is how a design system quietly stops being one. Read what an install writes before you keep it, per the CLI guide.
Where else to look
The honest list, because the answer is not always us:
| Source | Best for | Trade-off |
|---|---|---|
| shadcn/ui | The primitives underneath all of this | No sections and no footers |
| The registry directory | Comparing this set against its neighbours | Only registries that publish an index |
| The registry's own site | The full 193 items, including what is not here | No previews beside other registries |
| 21st | The 29 published here, searchable next to everything else | Quality varies by author, so preview before you take it |
Taking one
Every component page has a live preview and the code. Installing goes through the shadcn CLI against our registry:
That key comes from your 21st account, and installs require a membership. Set API_KEY_21ST once in your shell and the command works for anything in the catalogue.
Frequently asked
- What is Spectrum UI known for?
- Footers, going by how it is actually used: three of its five most-taken components here are footer sections, including a stacked circular variant and an oversized-wordmark one. The set itself is general, with 193 items in its registry index.
- Why do footers get taken more than anything else?
- A footer is the last thing anyone builds, it is nearly always the same six link columns, and taking a finished one is an easy decision with almost no downside. The checks that remain are small: real links rather than buttons, a working theme toggle, and no navigation that exists only there.
- What should you watch for in a registry assembled from other registries?
- Duplication. If you already have a card from one set, taking another gives you two components with the same job and different tokens, which is how a design system quietly stops being one. Read what an install writes before you keep it.
- Where does a general registry fit?
- In the middle layer: primitives underneath, one general registry for product surfaces such as forms, badges, dropdowns and boards, and individual components for the parts meant to stand out. Its best entries are the harder inputs, a calendar or a dual range slider, which cost a day each to write properly.