Arc vs Aceternity UI: which should you use?
Aceternity UI is a React component library of animated, visually bold components, blocks and templates for landing pages. Arc is a React library of components and complete blocks for product interfaces, built so coding agents can find and use them correctly.
On this page
The short version
Both are copy-the-source libraries built on React and Motion, with a free tier and a paid tier, and both publish an MCP server for coding agents and an llms.txt file. They differ in what they are aiming at.
Aceternity is aimed at landing pages, with effects such as aurora backgrounds and card stacks and a set of full Next.js templates. Arc is aimed at product interfaces, with inputs, tables, charts, dialogs and blocks, and quieter motion that explains what changed.
We make Arc, so read this with that in mind. Every fact about Aceternity UI below comes from their own site, docs, npm package or repository, and we say where the other library is the better pick.
Fact table
| Topic | Arc | Aceternity UI |
|---|---|---|
| What it is | React components and blocks for product interfaces, built to work with AI coding agents | Animated components, blocks and templates for landing pages |
| Stack | React, TypeScript, CSS Modules with CSS variables, Motion. Tailwind is optional. | React, Tailwind CSS, Motion |
| Size | 161 components and 91 blocks (110 components and 22 blocks are free) | Advertises 200+ components, blocks and templates, with 116+ free components |
| License | MIT for free items. Arc Pro license for Pro items: unlimited projects, no reselling the source as a kit. | Pro license allows unlimited end products and no resale. Check their licence page for the free components. |
| Free and paid | Free components and a starter set of blocks. Pro is $199 once, or $129 a year. Team is $599 once for up to 10 people. | Free components. Pro has annual, lifetime and team plans; see their pricing page for current prices. |
| Install | npx shadcn@latest add @uiarc/button | Copy and paste for components. Blocks and pages install with the shadcn CLI. |
| Motion | Motion with shared spring presets. Components include a reduced motion branch. | Motion |
| MCP and AI support | Remote MCP server (sign in with a free account), llms.txt and llms-full.txt, markdown for every component, an agent skill. | MCP server for coding agents (see their site for setup) and llms.txt. |
| Best for | Product UI such as dashboards, settings, forms, tables and onboarding, with motion built in | Bold, visual landing pages with full-page templates |
Last verified October 13, 2026. Arc facts are read from Arc itself. For Aceternity UI, see ui.aceternity.com for anything that has changed, especially prices.
Where they differ
Visual language
Aceternity leans into dramatic visual effects, which suits a marketing site that needs to stand out. Arc's design rules keep surfaces neutral and use motion to show cause and effect, which suits dense screens people use every day.
Styling
Aceternity's site lists React, Tailwind CSS and Motion as its stack, so your project needs Tailwind. Arc uses CSS Modules and CSS variables, so it works next to Tailwind or without it.
License and pricing
Aceternity's components are free. Blocks, templates and full pages are part of a paid plan, and the plans include annual, lifetime and team options. Its Pro license allows unlimited end products for you or your clients and forbids reselling the code. Arc's free items are MIT licensed, with 110 components and 22 blocks free. Arc Pro is $199 once or $129 a year, and the team plan is $599 once for up to 10 people, and the Pro license likewise does not allow reselling the source as a kit. Check Aceternity's pricing page for current prices.
Install
Aceternity components are copied and pasted, while its blocks and pages install with the shadcn CLI. Every free Arc item is a registry item you can install by name, and you can copy the source by hand if you prefer.
MCP and AI support
Aceternity's homepage says you can connect an AI agent to its MCP server so it builds with the components. Arc's MCP tools return when to use a component and when not to, its props, keyboard behavior, accessibility and motion notes, and the install command, and an agent skill adds Arc's design rules.
Which to choose
Choose Aceternity UI if
- You are building a landing page and want striking visual effects and full-page templates.
- Your project already uses Tailwind CSS.
- You want a catalog that is organized around marketing sections.
Choose Arc if
- You are building product screens such as dashboards, settings, forms and tables.
- You want components that work with or without Tailwind.
- You want your coding agent to read when to use a component, its props and its keyboard behavior before it installs.
- You want quieter motion with a reduced motion branch in every animated component.
Using both
They can live in the same project. Use Aceternity for the marketing site and Arc for the app behind it, and install each through the shadcn CLI.
Install
Both install with the shadcn CLI. Register Arc once in components.json, then install by name.
{ "registries": { "@uiarc": "https://uiarc.dev/r/{name}.json" }}# Arcnpx shadcn@latest add @uiarc/button # Aceternity UI: copy components from their site, and install blocks with the# shadcn CLI command shown on each block page.Frequently asked questions
Is Aceternity UI free?
Its free components cost nothing. Blocks, templates and full pages are part of a paid All-Access plan with annual, lifetime and team options. See their pricing page for current prices.
Does Aceternity UI need Tailwind CSS?
Their site lists React, Tailwind CSS and Motion as the stack, so yes, plan for Tailwind. Arc does not need it, because its components use CSS Modules and CSS variables.
Can I use Aceternity UI and Arc together?
Yes. They can sit in one project, for example Aceternity on the marketing pages and Arc in the app. Each has its own tokens, so check light and dark themes after mixing.
Which is better for a SaaS dashboard?
Aceternity's components, blocks and templates are aimed at landing pages. Arc has 161 components and 91 blocks, including dashboard blocks, data tables, charts and form controls, so it is the closer fit for app screens. For the marketing site in front of the app, Aceternity is a good fit.
Does Aceternity UI have an MCP server?
Its homepage says you can connect your AI agent to the Aceternity UI MCP server. See their site for setup. Arc's MCP server is at https://uiarc.dev/api/mcp.