140 small business homepages failed on HTTPS alone. A broken certificate can hide you from AI
Short answer: 183 of the 3,693 small business homepages we checked (5.0%) didn't load at all, and 140 of those (3.8% of all sites) failed because of an HTTPS certificate or TLS error. An AI tool that can't open your homepage can't quote it.
What went wrong
| Why the homepage didn't load | Sites |
|---|---|
| HTTPS certificate or TLS error | 140 |
| HTTP error (the server returned an error page) | 33 |
| Redirect loop | 6 |
| Other | 4 |
The certificate errors were mostly the boring kind: a certificate issued for a different name than the one the site uses (for example, it covers www but not the bare domain), or one that simply expired.
Why AI tools don't push through
When your browser hits a bad certificate, it shows a warning and lets you click "continue anyway." Crawlers don't click. They treat the page as unreachable and move on to other sources about you, like directories and review sites, which may be out of date.
Which businesses had it most
Real estate (16 of 162, 9.9%) and hotels (19 of 202, 9.4%) had the highest share of homepages that didn't load. Vets and pet services had the lowest (6 of 207, 2.9%).
Sites behind Cloudflare almost never had this problem: 9 of 1,481 (0.6%), against 174 of 2,212 (7.9%) for everything else. Cloudflare issues and renews certificates for the sites it fronts, which takes this failure off the table.
The 5-minute check
- Type your domain both ways, with and without "www", in a private browser window.
- If either shows a warning, send your host a screenshot and ask them to fix the certificate for both names.
- Run the free AI crawler check. It tells you if your homepage loads for an identified crawler.
Data: Preferly, "How many small business websites block AI crawlers?" (2026), https://www.preferly.ai/research/ai-crawler-study. We checked 4,111 small and local business websites in 26 US cities on Oct 22, 2026 and analyzed the 3,693 that responded. The aggregate data is free to reuse under CC BY 4.0 with that credit. Sites that didn't respond at all, or redirected to plain http, were excluded from the 3,693, so the real failure rate is likely a bit higher.
Questions
My site loads fine for me. Could it still have a certificate problem?
Yes. Some browsers fill in a missing certificate piece or remember an old exception. A crawler does a strict check, so it can fail where your browser didn't.
Who fixes a certificate error?
Usually your host or whoever set up your domain. Many hosts renew certificates for free; the problem is often a domain that points somewhere the certificate doesn't cover.
3 AI models, 5 customer questions, about a minute. Or check whether AI crawlers can reach your site.
No email. It reads your robots.txt and homepage, the way AI crawlers do.