AI Training Opt-Out Header on new websites
AI Training Opt-Out: HTTP header declaring publisher opt-out of AI training on content
- Sites using AI Training Opt-Out Header
- 17
- since May 2026
- Last 30 days
- 0.0%
-
of new sites, to Oct 21
no change on the 30 days before - Last 7 days
- 0.0%
- of new sites, 7-day average
no change on the week before
| First seen | May 22, 2026 |
|---|---|
| Last seen | Oct 17, 2026 |
What we found
- AI Training Opt-Out Header appeared on 8 new sites in the last 30 days.[1]
Share of new sites using AI Training Opt-Out Header
The line is the 7-day average share of new sites that use AI Training Opt-Out Header, since 10 September.
Who uses AI Training Opt-Out Header
| Type | Sites | Share | Bar |
|---|---|---|---|
| AI | 2 | 18.2% | |
| Education | 2 | 18.2% | |
| Health | 2 | 18.2% | |
| Design | 1 | 9.1% | |
| Developer Tools | 1 | 9.1% | |
| E-commerce | 1 | 9.1% | |
| Finance | 1 | 9.1% | |
| Marketing | 1 | 9.1% |
| Ending | Sites | Share | Bar |
|---|---|---|---|
| .com | 6 | 35.3% | |
| .dev | 4 | 23.5% | |
| .ai | 1 | 5.9% | |
| .app | 1 | 5.9% | |
| .io | 1 | 5.9% | |
| .me | 1 | 5.9% | |
| .net | 1 | 5.9% | |
| .org | 1 | 5.9% |
Security on new sites
| # | Movement | Tool | Share of category | Bar | |
|---|---|---|---|---|---|
| 1 | – | HSTS | 87.3% | ||
| 2 | – |
Cloudflare Bot Management
|
25.3% | ||
| 3 | – |
Google reCAPTCHA
|
3.5% | ||
| 4 | ▲1 |
Anubis
|
0.2% | ||
| 5 | ▼2 |
DDoS-Guard
|
0.2% | ||
| … | |||||
| 83 | – | AI Training Opt-Out Header | <0.1% | ||
All-time shares across the new sites we track: of all of them, and of the sites using any Security tool. All 402 in Security
Recently launched products built on AI Training Opt-Out Header
6 of the 17 sites using AI Training Opt-Out Header are product launches we list individually. The other 11 are new business and personal sites: they count towards the figures above but are not listed here. A watch sends them to you.
Watches, exports and the API give you all 17 sites using AI Training Opt-Out Header, from £15 a month.
Notes
- These figures cover websites that went live since April 2026, not the web as a whole.
How this page is made
FirstSited looks at each new website near the day it goes live and records what it was built with. We do not go back later, so these figures describe what sites launch with, not what they run today. A site counts towards AI Training Opt-Out Header when we detect AI Training Opt-Out Header on it at that look.
Every share on this page is a proportion of the new sites we were tracking at the time. Sites we found across the wider web count towards the figures, but only product launches are listed by name. How we detect technologies · How we find new sites