We scanned 197 websites. Here's what gives AI-built ones away.

The gap, in numbers

• Median Slop Score: 72 for builder sites, 15 for designer-made sites, 35 for Show HN pages.
• Slop tells per site: 12.6 on builder sites versus 4.2 on designer-made ones.
• Strip out the builder fingerprints (domain, metadata, code leftovers) and builder sites still land at a median of 65. It isn't just provenance: the design is factory default too.
• Designer-made sites don't score zero. The highest was supabase.com at 55, then cal.com and Things at 41. Careful sites have defaults too. What differs is how many.

What shows up on builder sites

Share of the 27 builder sites with each tell, with the share of the 22 designer-made sites in parentheses:

• Untouched shadcn/ui components: 89% (23%).
• The usual typeface (Inter, Geist or the system font, with nothing paired with it): 85% (23%).
• Metadata the builder left behind: default title, description, social image or favicon. 81% (0%).
• Builder leftovers in the code, like the attributes Lovable adds: 81% (0%).
• Lucide icons: 63% (9%).
• One of the Google Fonts models always reach for: 56% (0%).
• Everything centered, block after block: 48% (9%).
• Icons inside a little colored square on every card: 41% (0%).
• The template section lineup: how it works, testimonials, pricing, FAQ, in that order. 41% (5%).

What weighs the most

Common isn't the same as heavy. Slop Score weights each tell by how well it separated sites during calibration, and the one that added the most points turned out to be the easiest to fix: the builder's default metadata. It accounts for 15% of all points on builder sites, and it's the single biggest contributor on 19 of the 27.

Typography comes next (9% of points), then untouched shadcn components (6%). Put differently: your <title>, description, social image and heading font explain a good part of why a site looks generated. That's an afternoon of work.

Purple isn't the main tell anymore

We found some kind of purple (the purple-to-blue gradient, an indigo accent or the cyan-and-violet palette) on 10 of the 27 builder sites, 2 of the 22 designer-made sites and 22 of the 148 Show HN pages. It still separates the groups, but only one builder site in three has it.

Most generated sites now come out neutral gray with a single accent. That's the point of our guide to AI slop in web design: the tools learned to hide the obvious stuff.

Tells that prove nothing

Some tells that get passed around as "AI" show up just as often, or more, on designer-made sites:

• Dark mode: 48% of builder sites, 55% of designer-made ones.
• Decorative animation: 15% versus 36%.
• Scrolling logo marquee: 7% versus 14%.
• Dot or grid background: 11% versus 18%.

That's why dark mode barely counts in Slop Score: it shows up in the report, but it doesn't decide anything.

Lovable, Bolt, Replit and v0

Only Lovable has a sample big enough to say something. Its 19 sites had a median of 77: all 19 kept the default metadata and untouched shadcn components, and 16 used the usual typeface. It's the most recognizable builder, mostly because almost nobody changes what it puts in the <head>.

We have too few of the rest: the 3 Bolt sites had a median of 69, the 3 Replit sites 52, and the single v0 site 72. Three sites can't rank one builder against another, so we won't. What each one leaves behind is in our guide to Lovable, v0 and Bolt sites.

What Show HN is shipping right now

Across the 148 Show HN pages, the most common tell was the usual typeface: it's on 66% of them and the top contributor on 47. Then come the template hero, purple, and small all-caps labels above the headline.

design-slop-cop had marked by hand which patterns each page had. The more patterns a person confirmed, the higher Slop Score went: a median of 22 with none, 33 with two, 49 with three, 70 with five and 79 with six or more.

How we measured

• Each site was loaded in Chrome at 1440 px and on mobile, scrolled to the bottom, and Slop Score checked the DOM, the CSS and the served code. No weights were changed for this study.
• We left out the 32 sites that didn't load (dead domain, bad certificate, 404, over 90 seconds) and the 20 that loaded with almost no text (a login wall or an app that never finished loading).
• The builder and designer-made sites are the same ones Slop Score was calibrated on, so the gap between them is optimistic. The designer-made sites come from well-known studios and designers, not an average of the web.
• design-slop-cop's labels date from April 2026, and some pages have changed since.
• We kept every site's result, tell by tell, plus the scripts to rerun the scan with the same rules.

What to do with this

1. Write your own <title>, description and social image, and swap the favicon. It weighs the most and takes the least time.
2. Pick your heading typeface.
3. Change the shadcn theme values: colors, corner radius, shadows.
4. Check whether each section is there because your product needs it or because it came with the template.

The full order, with the reasoning for each step, is in how to make your website not look AI-generated.