How to Block CCBot: One Rule That Stops 50+ AI Models
CCBot is Common Crawl's web crawler — and Common Crawl data feeds the training sets for GPT, Gemini, Llama, Mistral, and most open-source LLMs. Block CCBot once, block them all.
Updated March 2026
The one rule you need
User-agent: CCBot Disallow: /
Add to robots.txt. Common Crawl reliably respects it. Deploy, done — your content is excluded from the next crawl snapshot.
What Is Common Crawl?
Common Crawl is a US non-profit that has been crawling the open web continuously since 2008. It publishes monthly snapshots — petabytes of raw web data — under an open licence that anyone can download for free.
This free, open dataset became the foundation of modern AI training. Rather than crawling the web themselves, AI companies download and process Common Crawl data — cleaning it, filtering it, and using it as the base of their training corpus. The result: blocking CCBot affects not just Common Crawl itself, but every model trained on its data.
The C4 dataset (Colossal Clean Crawled Corpus), derived from Common Crawl, is one of the most widely used training datasets in AI history.
Which AI Models Use Common Crawl Data?
Most major LLMs. Here are the confirmed ones with verified public documentation:
| Company | Models |
|---|---|
| OpenAI | GPT-3, GPT-4, GPT-4o series |
| Google DeepMind | Gemini, PaLM, T5 |
| Meta | Llama 1, 2, 3 |
| Mistral AI | Mixtral, Mistral 7B |
| TII UAE | Falcon 7B, 40B, 180B |
| EleutherAI | GPT-NeoX, Pythia |
| Hugging Face | StarCoder, many open models |
| Allen Institute (AI2) | OLMo series |
This list is non-exhaustive. Hundreds of open-source and research models also use Common Crawl-derived data.
What Blocking CCBot Actually Does (and Doesn't Do)
- • Your pages entering future Common Crawl snapshots
- • Future AI models using those snapshots for training
- • CCBot crawl traffic on your server
- • Already-trained models (GPT-4, Llama 2, etc.)
- • Content already in existing CC snapshots
- • Other AI crawlers (GPTBot, ClaudeBot — block separately)
- • Search engine indexing (Googlebot unaffected)
The prospective effect: Blocking CCBot today affects models trained 6–18 months from now, not models that already exist. If your content appeared in Common Crawl snapshots before you added the block, that data is already in the corpus of deployed models. The block cuts off future collection.
Will Blocking CCBot Hurt My SEO?
No. CCBot and search engine crawlers are completely separate systems.
Googlebot, Bingbot, and other search engine crawlers use their own crawlers and ignore what you say about CCBot. Blocking CCBot has zero effect on your Google rankings, Bing rankings, or any search engine indexing. You can safely add the CCBot Disallow rule without any SEO concern.
Frequently Asked Questions
Is there a way to remove my content from existing Common Crawl datasets?
Common Crawl provides a URL removal request process at commoncrawl.org. You can submit specific URLs or domains for removal from future published snapshots. Note: this does not retroactively remove data from snapshots already used to train existing AI models.
Does blocking CCBot affect my site's ranking in AI answers?
Indirectly, over time. If AI models use future Common Crawl data for training, blocking CCBot means your content won't be in those training runs. But this affects future models, not deployed ones. Your site's presence in ChatGPT, Gemini, or Claude answers reflects already-trained data, which is unaffected by your CCBot block today.
Do I need to block CCBot separately for each subdomain?
robots.txt applies only to the domain it's served from. If you have content at blog.example.com and shop.example.com, each needs its own robots.txt with the CCBot Disallow rule. A rule at example.com/robots.txt does not cover subdomains.
What's the difference between CCBot and AI2Bot?
CCBot is Common Crawl's general-purpose web crawler, whose data feeds many AI models. AI2Bot is the Allen Institute for AI's crawler, which is used specifically for building AI2's research datasets (like Dolma and the ROOTS dataset). Both contribute to AI training data. Blocking CCBot does not block AI2Bot.
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