We measured 18 public Bolt sites (median score 49/100) but did not have a sample for Durable, so the numbers below cover one side only. The rest of the page compares how each builder can be recognised and what its sites usually get wrong.
Side by side
from our study of 780 public sites
Bolt
Durable
Type
AI builder (site written from a prompt)
AI builder (site written from a prompt)
Default hosting
*.bolt.host
durable.co
Sites in our sample
18
not measured
Median site score
49/100
not measured
Sites with a critical problem of their own
33.3%
not measured
Call a Supabase database from the browser
33.3%
not measured
No main heading (H1)
77.8%
not measured
No meta description
5.6%
not measured
Zoom disabled on phones
0%
not measured
Builder badge left on
0%
not measured
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 Durable.
What usually goes wrong: Copy that says nothing specific. Generated text is grammatical and generic. It rarely names the town you serve, what you charge, or what makes you different, which is exactly what a local customer is looking for.
Can you tell whether a site was built with Bolt or Durable?
Usually, yes. Each leaves its own traces: Bolt on *.bolt.host and in its scripts, Durable on durable.co 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 Durable?
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.