Why Your Claude-Built Website Looks AI-Made: The 10 Tells, and One Rule That Fixes Them
A developer's list of the 10 signs that give away an AI-built site went viral, and Claude's defaults hit most of them. What each tell looks like, why Claude does it, and the one rule to paste into Claude once so every site after it looks designed.
On September 27 a developer who posts as hereticpleb published "10 Tells of a Slop UI", a list of the signs that give away an interface an AI built with nobody steering the design. It spread fast among developers, which means a lot more people now know exactly what to look for. If you build sites with Claude and don't tell it how they should look, you'll recognise most of the list. The post is here: https://hereticpleb.vercel.app/blog/10-tells-of-slop
None of these are bugs. They're the choices Claude makes on its own when your prompt says what the site is for but not what it should look like. So you don't fix them one site at a time: you tell Claude once.
The 10 tells
| # | The tell | What it looks like |
|---|---|---|
| 1 | Gradients everywhere | Purple, violet and indigo gradients on the hero, the buttons, the logo, the background |
| 2 | Rainbow vomit | Every icon and section in a different bright colour, with no colour doing a job |
| 3 | Pulsing badges | Little "New", "Beta" or "Live" pills with a glowing, pulsing dot |
| 4 | Fingernail cards | Rounded cards everywhere: every feature, stat and line of text in its own small box |
| 5 | Emoji slop | Emoji used as icons, bullets and decoration |
| 6 | Misaligned stuff | Icons and loose elements that sit a few pixels off the grid |
| 7 | Font selection | The same default fonts on every site (Inter, a mono face), with no real type choice |
| 8 | Redundant text | Lines that only make sense in the chat that built the page: "Built with...", labels that repeat the heading |
| 9 | Glassmorphism | Frosted, see-through glass panels as the default look |
| 10 | Generic taglines | "Elevate", "seamless", "next-generation", "the AI-powered platform for everything" |
Keep reading
Free, for an email.
Unlocks 5 more sections, 2 copy-paste prompts, the document version, and every other guide on the site, for free. Enter your email once to keep reading.
19,000+ follow where these guides come from.No spam. Unsubscribe in one click.