Content Signals
Cloudflare Content Signals (Content-Signal in robots.txt) declare how content may be used for search, AI input, and AI training.
- Category
- Bot access control
- Standard
- Emerging checkEmerging
- Off by default, turn on in settings
Who supports it
GeminiNot supported
Published 31 Aug 2026 · last checked 9 Oct 2026: Google: How Google interprets the robots.txt specificationThis is implied rather than a named denial. Google 'supports the following fields ... user-agent, allow, disallow, sitemap' and other rules 'are ignored by the robots.txt parser', so Content-Signal has no effect on Google crawlers, including the Google-Extended controls. Mueller's Reddit comment (reported by Search Engine Roundtable on 2026-07-06) could not be fetched directly.
26 others: no evidence yet. See every agent and browser
What it checks
robots.txt says whether a crawler may fetch a page. Content Signals, proposed
by Cloudflare, say what the content may be used for once fetched. The extension
looks in /robots.txt for a Content-Signal: directive, or a comment that
mentions content-signal.
Results
| Status | When |
|---|---|
| Pass | A Content-Signal directive or comment is in robots.txt |
| N/A | No Content Signals are declared |
How to fix
Add a Content-Signal line to a User-agent group in robots.txt, setting
each use to yes or no:
User-agent: *
Content-Signal: search=yes, ai-input=yes, ai-train=no
Allow: /search covers building a search index, ai-input covers using content to
answer a question in real time, and ai-train covers training or fine-tuning
models. Leaving a signal out expresses no preference for that use.
Support by agent and browser
Announced means the vendor’s own docs or announcement say so. Published is the date on the vendor’s own page, where it has one. Checked is the last time our weekly research found that page still saying so.
| Agent | Status | Source |
|---|---|---|
| AI assistants | ||
| Gemini Google | Not supported | no Google: How Google interprets the robots.txt specification Published · Checked This is implied rather than a named denial. Google 'supports the following fields ... user-agent, allow, disallow, sitemap' and other rules 'are ignored by the robots.txt parser', so Content-Signal has no effect on Google crawlers, including the Google-Extended controls. Mueller's Reddit comment (reported by Search Engine Roundtable on 2026-07-06) could not be fetched directly. |
No evidence yet26
- ChatGPT
- Claude
- Perplexity
- Copilot
- Meta AI
- ChatGPT Atlas
- Comet
- Dia
- Gemini in Chrome
- Edge Copilot Mode
- Claude Code
- Cursor
- Codex
- GitHub Copilot
- Windsurf
- CCBot
- Applebot
- Amazonbot
- Bytespider
- Cohere
- Mistral
- DuckAssist
- Chrome
- Edge
- Firefox
- Safari
Names and marks belong to their owners and are used only to identify products. None of these vendors is affiliated with Sitebulb. Spotted something out of date? Send a correction.
Adoption on the top 100 sites
4 of 100 measured sites implement it
Sites implementing it4
- #2 cloudflare.com
- #68 zoom.com (via zoom.us)
- #106 sentry.io
- #128 one.one.one.one (via cloudflare-dns.com)
Overview
How this rating is worked out2 of 9 points
| Factor | Points | Why |
|---|---|---|
| Vendor support | 0 / 3 | 0 vendors supporting, 0 partly or planned |
| Top-100 adoption | 1 / 3 | 4% of measured sites |
| Spec maturity | 1 / 3 | Single-vendor spec |
8 or more points is Established, 5 to 7 is Gaining traction, 2 to 4 is Speculative and under 2 is Stalled. A feature is also Stalled when more vendors have said no than yes. Read the spec.
Community insights
No community insights for this feature yet.
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