CCBot

CCBot crawls billions of web pages per cycle, producing petabyte-scale datasets that represent a snapshot of the public web. Key statistics:

• Archives contain 250+ billion pages spanning 17+ years
• A single monthly crawl can exceed 300 TiB of uncompressed content
• Data is stored in WARC (Web ARChive) format, preserving raw HTTP headers and payloads
• The corpus is hosted on Amazon S3 as part of the AWS Open Data Sponsorship Program

Common Crawl's datasets serve as a primary pre-training corpus for many large language models. Organizations filter and process the raw WARC files to extract clean text. Notable models trained on Common Crawl data include:

• GPT-3 and subsequent OpenAI models
• LLaMA and LLaMA 2 by Meta
• BLOOM by BigScience
• Stable Diffusion for alt-text image pairing This makes CCBot indirectly one of the most influential crawlers in shaping AI behavior.

CCBot adheres to the Robots Exclusion Protocol and identifies itself with the user-agent token CCBot. To control its access:

• Use User-agent: CCBot in robots.txt to set specific rules
• CCBot respects Crawl-Delay directives to manage server load
• It does not respect nofollow meta tags for crawl purposes, as it archives raw HTML
• The crawler operates from a defined set of IP ranges that can be verified against Common Crawl's documentation

Example robots.txt directive:

codeCopy
User-agent: CCBot
Disallow: /private/
Crawl-Delay: 10

CCBot is fundamentally different from crawlers like GPTBot or ClaudeBot. Key distinctions:

• Purpose: CCBot archives for public research, not proprietary model training
• Opt-out: Blocking CCBot removes content from a public good; blocking GPTBot protects private IP
• Attribution: Common Crawl does not generate content; it provides raw data that others process
• Latency: CCBot's impact is delayed and indirect, as models train on snapshots months or years old

This distinction is critical for crafting granular crawl policies that balance openness with protection.

CCBot conducts monthly or bi-monthly crawl cycles, not continuous crawling. It uses a breadth-first strategy to maximize domain diversity rather than depth on any single site. Server impact considerations:

• CCBot typically fetches only a few pages per domain per cycle
• It prioritizes highly linked, publicly accessible pages
• It does not execute JavaScript; it archives static HTML responses
• Respects 429 Too Many Requests status codes and backs off accordingly

For most sites, CCBot represents negligible server load compared to commercial search engine crawlers.

The standard mechanism for controlling CCBot's access. Website owners can disallow CCBot entirely or restrict it from specific paths using the User-agent: CCBot directive in robots.txt. Unlike some commercial crawlers, CCBot honors the Crawl-Delay directive to manage server load. Example directive:

• User-agent: CCBot
• Disallow: /private/
• Crawl-Delay: 10

The broader technical and policy framework for preventing web content from being used in foundation model training. While CCBot respects robots.txt, the absence of a universal opt-out standard means publishers must individually block each AI crawler. Key mechanisms include:

• robots.txt disallow rules for specific user-agent tokens
• X-Robots-Tag HTTP headers for non-HTML assets
• Terms of Service clauses prohibiting AI training

A critical distinction for publishers: CCBot is an open-data crawler serving the research community, while GPTBot is OpenAI's proprietary crawler for training its commercial models. Blocking one does not affect the other. CCBot's data is publicly available to anyone, including competitors, whereas GPTBot's crawled data remains within OpenAI's closed ecosystem. Publishers with sensitive or proprietary content often block GPTBot while allowing CCBot for academic use.

CCBot stores crawled data in the Web ARChive (WARC) format, an ISO standard (ISO 28500) for preserving web content. Each WARC file contains:

• Raw HTTP request and response headers
• Full HTML payload of crawled pages
• Metadata including crawl timestamp and IP address
• Content digests for integrity verification This structured format enables efficient batch processing by training pipelines and ensures reproducibility in research.

The concept of allocating server resources to CCBot without degrading performance for human users. CCBot crawls at a conservative rate by default, but high-traffic sites should explicitly configure limits. Best practices include:

• Setting a Crawl-Delay of 5-10 seconds in robots.txt
• Monitoring 429 (Too Many Requests) responses in server logs
• Using dedicated crawl subdomains for large-scale content donation
• Analyzing CCBot's request patterns to identify anomalies