In our sample, Bolt sites score higher: a median of 49/100 against 45/100 for Webflow, a gap of 4 points. The score counts problems a visitor or a search engine would hit, such as missing headings, exposed keys and blocked zoom, so it says as much about how people use each builder as about the builder itself. One side is a small sample, so treat the gap as a hint rather than a verdict.
Side by side
from our study of 780 public sites
Bolt
Webflow
Type
AI builder (site written from a prompt)
Visual builder (designed by a person)
Default hosting
*.bolt.host
*.webflow.io
Sites in our sample
18
149
Median site score
49/100
45/100
Sites with a critical problem of their own
33.3%
15.4%
Call a Supabase database from the browser
33.3%
0%
No main heading (H1)
77.8%
11.4%
No meta description
5.6%
45%
Zoom disabled on phones
0%
0%
Builder badge left on
0%
0%
Highlighted: the better of the two on that row. Lower is better for every percentage.
Telling them apart
Bolt
How to spot it: Look at the address: *.bolt.host is Bolt hosting.
What usually goes wrong: Supabase keys in plain sight. We found a Supabase key in the JavaScript bundle of most Bolt sites we scanned. An anonymous key is meant to be public, but only if row-level security is switched on in the database. Many projects never turn it on, and then the key is enough to read every row.
How to spot it: Search the page source for a generator meta tag naming Webflow.
What usually goes wrong: The staging domain left indexable. A site reachable on both *.webflow.io and your own domain competes with itself in search unless the staging copy is blocked.
Can you tell whether a site was built with Bolt or Webflow?
Usually, yes. Each leaves its own traces: Bolt on *.bolt.host and in its scripts, Webflow on *.webflow.io and in its own markers. Paste the URL in the scanner above and it names the builder with the evidence it found.
Which is better for SEO, Bolt or Webflow?
Neither decides it alone. In our sample the biggest SEO gaps were a missing main heading and a missing meta description, both fixable on either platform. Compare the rows above, then scan your own site to see which of them apply to it.
Is a Bolt site worse than a hand-built one?
Not by being AI-built. The problems we see most are defaults nobody changed: titles, badges, blocked zoom, and database keys used without access rules. Each is a short fix once you know it is there.
Numbers from The AI-built web, October 2026: public sites on each builder's own hosting, scanned once. Read the method and its limits there.