Ask an AI agent for a landing page and you tend to get the same page: a cream background, a serif headline with one word in italics, identical rounded cards with a soft grey shadow. Anthropic's frontend design skill exists to stop that. It makes the agent write a short design plan first, check the plan against a list of the looks AI output falls into, and only then build.
What it does
The skill casts the agent as the design lead at a studio whose client has already turned down anything templated. In practice that means four things:
- Start from the subject. Colour, type and layout come from what the product is and who it is for. If the brief doesn't say, the agent proposes a subject and audience and asks you to confirm.
- Plan in tokens. Four to six named hex colours, one or two typefaces with their roles, a layout sketched in ASCII, and a few principles for the page.
- Check the plan for defaults. The skill lists the looks generated design keeps landing on and tells the agent to revise any part of its plan that matches one, unless your brief asked for it.
- Build with restraint. One bold element, everything else quiet, and a quality floor it doesn't announce: works on mobile, visible keyboard focus, reduced motion respected.
It also covers the words on the page: buttons named for what they do, errors that say how to fix the problem, sentence case, no filler.
Here is the line that sums it up, from the skill itself:
Spend your boldness in one place. Let one element be the memorable thing, keep everything around it quiet and disciplined, and cut any decoration that does not serve the brief.
From SKILL.md by Anthropic, Apache 2.0.
An example
Say you ask: "Build a landing page for a booking app for dog groomers." Without the skill, a typical first answer is a hero with a gradient, a big stat and three feature cards. With it, the agent first replies with a plan along these lines: who the page is for (independent groomers, on their phones between appointments), a palette taken from the job itself, a type pairing and why, and an ASCII sketch of the hero. It then points out which part of its first idea looked generic and what it changed. The code comes after you've seen that.
When to use it, and when not to
Use it when you're building a new page or restyling one and want it to look designed for its subject: landing pages, portfolios, dashboards, side projects you want to stand out.
Skip it when you already have a strict design system and just need a component built to spec. It will follow your system, but its planning step is wasted effort there. It's also not an accessibility audit; it sets a floor, and you still need to test.
What we checked
We read every file in the folder at the commit linked above: SKILL.md and
the Apache 2.0 LICENSE.txt. There are no scripts, no network calls and no
allowed-tools. It is instructions only, and nothing in it touches files
outside the project you're building or asks the agent to skip a
confirmation. The full checklist we use is in our
guide to checking a skill before you install it.
For fast React once the design is settled, pair it with Vercel's React best practices skill.