How to Audit If Your Website Is in the Common Crawl Dataset

Common Crawl is the single largest public repository of web crawl data, containing billions of web pages harvested over years of crawling. For businesses and technical SEOs, this dataset is critical: it serves as the foundational training corpus for frontier Large Language Models (LLMs) including OpenAI’s GPT models, Anthropic’s Claude, and Google’s Gemini.

If your website’s content is not present in the Common Crawl dataset, offline AI models will lack native knowledge of your brand, products, and services during training.

In this guide, we will look at how to run a quick 5-minute audit using simple command-line tools to verify if your website is included in the latest Common Crawl index.

Why Common Crawl Matters for AI Visibility (GEO)

Traditional Search Engine Optimization (SEO) focuses on dynamic crawling and index updates. Generative Engine Optimization (GEO), however, requires an understanding of static training corpuses. Because frontier LLMs undergo training phases that capture snapshots of the web, being included in major datasets like Common Crawl is a prerequisite for model representation.

When you audit your presence in Common Crawl, you verify two key factors:

Accessibility: Whether your server or robots.txt configuration is blocking Common Crawl’s user-agent (CCBot).
Inclusion: Whether your pages are actually indexed in the latest crawl cycles.

Running the 5-Minute Terminal Audit

You can audit your domain directly from your terminal. In the examples below, we will use tulabot.com as our target domain.

Step 1: Set Your Domain Variable

First, define a shell variable for your domain to make running the subsequent commands easier:

DOMAIN="tulabot.com"

Step 2: Test CCBot Accessibility

Before querying the index, confirm that Common Crawl’s bot isn’t blocked by your server, CDN, or firewall. We can test this by mimicking the CCBot/2.0 user-agent string using curl:

curl -A "CCBot/2.0" -I "https://$DOMAIN/"

What to look for:

HTTP 200 OK: Your server is open to CCBot.
HTTP 403 Forbidden / 401 Unauthorized: Your firewall, CDN (like Cloudflare), or server configuration is blocking the bot.
Connection Timeout: The bot is being actively drop-blocked by firewall rules.

Step 3: Query the Index API

Common Crawl provides a public Index API that allows you to query specific crawl archives. To check if your domain is in a specific crawl cycle (for example, CC-MAIN-2026-21), run the following command:

curl "https://index.commoncrawl.org/CC-MAIN-2026-21-index?url=$DOMAIN/*&output=json" | head

Note: Replace CC-MAIN-2026-21 with the latest crawl index identifier available on the Common Crawl Index Server.

Step 4: Interpret the Output

If your website is indexed, the API will return one or more JSON objects containing metadata for the crawled URLs, like this:

{
  "urlkey": "com,tulabot)/",
  "timestamp": "20260510020420",
  "url": "https://www.tulabot.com/",
  "mime": "text/html",
  "status": "200",
  "digest": "460GLY...",
  "filename": "crawl-data/CC-MAIN-2026-21/segments/..."
}

Each JSON line represents a specific page that was successfully crawled, along with the crawl timestamp, content type (mime), and HTTP status code (status).

If the query returns a blank response or a 404 error, your domain is not present in that specific crawl cycle.

Actionable Next Steps

If your audit reveals that your site is missing from the index:

Verify robots.txt: Ensure you are not blocking CCBot in your robots.txt file. Your file should allow crawling:
```
User-agent: CCBot
Allow: /
```
Review CDN Firewalls: Check if Cloudflare, AWS WAF, or other security providers are flagging CCBot as suspicious traffic and blocking it at the edge.
Check Backlinks: Common Crawl discovers pages primarily through links. Increasing the number of high-quality external links pointing to your site will improve its crawl priority.

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