Impeccable: a design guide for your AI assistant
Impeccable gives a designer's eye to the AI assistant that codes your pages. Used by the Kailli team since September 2026: verdict Optimized.
In short
Impeccable is a free design guide for the AI assistant that codes your pages: it makes them polished, not generic.
- Notre verdict
- Optimized Used by the Kailli team since September 2026, Impeccable is adopted: style approved on a mockup first, then studio-grade pages.
- Who it's for
- SMEs that have an AI assistant code their pages and want a studio-quality result, without hiring a studio for every tweak.
- Pricing
- Free and open source (Apache 2.0 license). Only your AI assistant's usage is paid, to its own vendor. relevé le
What is it?
An AI coding assistant, such as Claude Code, Cursor or Codex, writes a web page from a simple request. Left alone, it produces pages that are fine, but all look alike.
Impeccable gives it a designer's know-how: a vocabulary, written quality rules and a working method. You type no commands: you describe what you need, and the assistant applies the method.
What is it used for in a business?
- Build a sales or sign-up page: pick a style on a mockup first, then have it coded faithfully.
- Improve an existing page: ask for a critique, then a targeted fix to lighten, clarify or add breathing room.
- Keep visual consistency: the assistant rereads your audience, your tone and your brand guidelines before every change.
Our take
Strengths
- The style is chosen before the code. You compare directions on mockups and make the call. Your role becomes choosing and approving.
- The quality rules are written down. Readability, contrast, buttons, mobile version: the assistant checks them before delivering, not according to its own taste.
- Checking has an end point. One pass on desktop and mobile, one round of fixes, then it ships.
Limitations
- You need someone who can judge a design. The tool sometimes flags false defects, and the decisive tweaks often come from a human eye.
- The full cycle takes time: directions, critique, mockup, then code. And Impeccable won't invent a brand identity for you.
A typical case
A consulting firm's home page, chosen on a mockup before being coded
The situation
In September 2026, we were redesigning our consulting firm's home page. A first attempt, coded directly and then corrected, was clean but bland.
What we did
We reversed the order. The assistant proposed three visual directions, critiqued by a second AI assistant. We chose one, then approved its mockup on desktop and mobile. The code came after.
The result
A studio-quality page, more readable on mobile, with the approved copy untouched. But the final tweaks came from our own annotations on the screenshots.
Frequently asked questions
Is Impeccable free?
Yes. The guide and its tools are free and open source, under the Apache 2.0 license. You only pay for your AI assistant's usage, to its vendor.
Do you need to know how to code, and which assistant works?
Not to use it: you describe the page you want, in plain language. Impeccable works with Claude Code, Cursor and Codex, among others. Installation is a one-time step, following the vendor's instructions.
Does Impeccable replace a designer?
No. It avoids generic pages and lets you handle routine tweaks on your own. Brand identity and the final call remain the job of a designer or a demanding executive.
Getting started
Official sources
- Impeccable official website (new tab) checked on
- Documentation: installation and getting started (new tab) checked on
- FAQ, including pricing (it's free) (new tab) checked on
