CCBot (Common Crawl) Complete Guide
What Is CCBot?
CCBot is a web crawler operated by the nonprofit Common Crawl foundation. Unlike other bots, it is run by a nonprofit rather than an AI company. Common Crawl publishes collected web data as open datasets free of charge, and anyone in academia, research, or industry can use them.
The decisive difference from other bots: Blocking GPTBot stops OpenAI training only. Blocking CCBot does not remove data already in Common Crawl datasets from public access. Blocking only prevents future collection.
TL;DR
CCBot is a nonprofit open web archive crawler. Collected data is publicly distributed and has been used in many LLM training projects. robots.txt can block future collection, but has no retroactive effect on already collected and distributed data. Data already collected by CCBot cannot be reclaimed regardless of settings.
LLM Training That Used Common Crawl
Common Crawl data has been used in training various AI models. This is documented in academic papers and technical reports from those models. Common Crawl does not guarantee or require that its data be used for training; each company and researcher decides independently.
CCBot Identification Information
Information stated in Common Crawl official documentation (commoncrawl.org/ccbot, verified June 2026):
User-Agent string:
CCBot/2.0 (https://commoncrawl.org/faq/)
IP range verification:
- Public JSON: https://index.commoncrawl.org/ccbot.json
- Reverse DNS: [IP].crawl.commoncrawl.org pattern
⚠️ Note Common Crawl official documentation warns that crawlers impersonating CCBot exist. Do not rely on User-Agent alone; verify reverse DNS of the IP as recommended.
robots.txt Blocking — Meaning and Limits
What blocking prevents
User-agent: CCBot
Disallow: /
This setting blocks CCBot crawling from this point forward.
What blocking does not prevent
- Already collected data: Common Crawl publishes past crawl data on AWS S3. Already published datasets remain downloadable by anyone even after blocking.
- Existing trained models: LLMs already trained on Common Crawl data are not affected retroactively.
This is fundamentally different from blocking GPTBot or ClaudeBot. Blocking other AI bots stops that company's future training, but blocking CCBot does not reclaim already public data.
Common Crawl Opt-Out Registry
In addition to robots.txt, Common Crawl operates a separate Opt-Out Registry. Webmasters can request domain exclusion from future crawls. This also does not apply retroactively to already collected data.
Three robots.txt Examples
Scenario A. Full allow (default if currently being crawled)
# No separate configuration required. CCBot crawls normally.
Scenario B. Block future collection
# Block future CCBot crawls
# Note: no effect on already published datasets
User-agent: CCBot
Disallow: /
Scenario C. Block specific paths only
User-agent: CCBot
Disallow: /private/
Disallow: /members/
Blocking Impact Analysis — When Blocking Matters
| Situation | CCBot blocking effect |
|---|---|
| Early-stage site (not yet collected) | ✅ Effective — prevents future collection |
| Already collected in Common Crawl | Limited — only prevents additional collection |
| Protecting new content | ✅ Effective — prevents collection of new pages |
| Goal: reclaim published data | ❌ Not possible — Opt-Out Registry also has no retroactive effect |
Recommended Scenarios
New sites or content asset protection focus: Scenario B recommended. Block future collection to prevent new content from being added to the open dataset.
General SMB: Scenario A unless there is a specific reason. Common Crawl data contributes more to training data pools than direct AI answer citations. Whether to block has limited short-term impact on AI exposure.
Verification Methods
# Check CCBot traffic in server logs
grep -i "CCBot" /var/log/nginx/access.log | awk '{print $4, $7, $1}' | tail -50
# Reverse DNS verification (spoofing check)
host [IP address]
# Result should include .crawl.commoncrawl.org for legitimate CCBot
Frequently Asked Questions
Q. If I block CCBot, will my site information disappear from GPT?
A. Not necessarily. GPT models use training data from many sources beyond Common Crawl. Already trained models retain existing knowledge regardless of CCBot blocking. ChatGPT real-time search (OAI-SearchBot) is a separate channel unrelated to CCBot blocking.
Q. Does Common Crawl sell data for profit?
A. No. Common Crawl is a nonprofit foundation and publishes collected data free of charge. It does not sell data commercially. However, companies and researchers who use the data may do so for their own commercial purposes.
Q. How do I block CCBot together with other AI bots?
A. Configure each User-Agent separately. See the AI bots robots.txt matrix article for full templates.
Q. How can I confirm CCBot is actually crawling my site?
A. Filter server logs for CCBot. Verify reverse DNS of confirmed IPs matches the .crawl.commoncrawl.org pattern to check for spoofing.
References
- Common Crawl official CCBot documentation: https://commoncrawl.org/ccbot (verified June 2026)
- Common Crawl IP ranges: https://index.commoncrawl.org/ccbot.json
- Common Crawl Opt-Out Registry: https://commoncrawl.org/blog (see related posts)