Googlebot & Related Crawlers Explained – Types, Behavior & SEO Control (2025 Guide)

📌 Googlebot – Core Crawler for Google Search #

🛠 Types of Googlebot #

1. Googlebot Smartphone
   
   • Simulates a mobile user
     
   • Primary crawler for most sites (Google mainly indexes mobile version of content)
     
2. Googlebot Desktop
   
   • Simulates a desktop user
     
   • Still used, but less frequently than mobile crawler
     

👉 Note:
Both share the same User-agent: Googlebot in robots.txt, so you cannot block one without blocking the other.

🌐 How Googlebot Crawls Your Site #

• Crawls most sites once every few seconds (on average)
  
• Can crawl the first 15 MB of HTML or supported text-based files (uncompressed size)
  
  • CSS, JS, images are fetched separately
    
• Crawls primarily from US-based IPs (Pacific Time zone)
  
• Discovers URLs via:
  
  • Internal/external links
    
  • Sitemaps
    
  • Indexed pages
    

🚫 Blocking Googlebot (Crawl vs Index) #

• Stop crawling: Use robots.txt
  
• Stop indexing: Use noindex
  
• Block access completely: Password protect or restrict server access
  ⚠️ Blocking Googlebot affects Google Search, Images, Video, News, Discover
  

✅ Verifying Googlebot (Avoid Fake Crawlers) #

• Why? Some bots spoof Google’s user agent
  
• How to verify:
  
  1. Reverse DNS lookup → Confirm hostname ends with .googlebot.com or .google.com
     
  2. Match IP against Googlebot IP ranges
     

💡 Quick FSIDM Tip for Students:
If your site shows crawling overload or errors in Search Console, it’s often not Googlebot being aggressive—it may be fake bots spoofing Googlebot UA. Always verify before blocking.

📖 What is Google Read Aloud? #

• User Agent Name: Google-Read-Aloud
  
• Purpose: Reads web pages aloud using Text-to-Speech (TTS)
  
• When it Activates:
  
  • Only when a user with TTS enabled visits a page
    
• Where it’s Used:
  
  • Google Go
    
  • Google Read It
    
  • Read Aloud in Google app
    
  • Other Google TTS-enabled services
    

🔍 Crawl Frequency & Behavior #

• Not a web crawler (no link following)
  
• Triggered by user action (not automated crawling)
  
• Caching:
  
  • Google caches content to save bandwidth
    
  • But multiple requests for the same page may still occur
    

🚫 How to Block or Control It #

• Robots.txt → ❌ Does NOT work (because it’s user-triggered)
  

Block completely:

<meta name=”google” content=”nopagereadaloud”>

Paywalled or subscription content:
Use structured data to mark restricted content:

“isAccessibleForFree”: false

📜 Old vs New User Agent #

• Current: Google-Read-Aloud
  
• Old (deprecated): google-speakr
  

💡 FSIDM Pro Tip for Students:
If you run a membership site, premium articles, or gated content, always use nopagereadaloud or mark isAccessibleForFree:false in structured data — otherwise, Google’s TTS may read it aloud to users for free.

🌐 What is APIs-Google? #

• User Agent Name: APIs-Google
  
• Purpose:
  
  • Delivers push notifications for Google APIs
    
  • Lets apps avoid constant polling of Google servers
    
• Why Ownership Verification?
  
  • Google ensures the developer owns the domain before allowing push notifications
    
  • Prevents abuse
    

📡 How APIs-Google Accesses Your Site #

• Uses HTTPS POST requests to send push notifications
  
• Retries failed requests:
  
  • Exponential backoff retry schedule (up to several days)
    
• Traffic pattern:
  
  • Can be steady (if updates are regular)
    
  • Or spiky (if resources change rapidly or retries happen often)
    

⚙️ How to Prepare Your Site #

• SSL Certificate Required (must be valid)
  
  • ❌ No self-signed certs
    
  • ❌ No certs from untrusted authorities
    
  • ❌ No revoked certificates
    
• Respond quickly to notifications (within seconds) to avoid repeated retries
  

🚫 How to Block APIs-Google #

• Unregister notifications:
  
  • Contact whoever registered the push endpoint and disable it
    

Robots.txt:

User-agent: APIs-Google  

Disallow: /

•  (Note: It ignores Googlebot rules, only responds to APIs-Google token)
  

✅ Verifying APIs-Google Requests #

• Spoof check:
  
  • Look up source IP of request claiming APIs-Google
    
  • Reverse DNS lookup → Must resolve to googlebot.com or google.com
    

💡 FSIDM Tip for Developers:
If APIs-Google traffic is hitting your site too often, it’s usually due to:

• A misconfigured app not acknowledging notifications
  
• A push endpoint responding too slowly
  👉 Fixing those saves bandwidth and keeps Google from hammering your server.

📌 What is Feedfetcher? #

• User Agent Name: Feedfetcher-Google
  
• Purpose:
  
  • Retrieves RSS & Atom feeds for Google News and PubSubHubbub
    
  • Only podcast feeds may appear in Google Search results
    
• Trigger: Activated only when a user adds a feed to a service/app (not an automated crawl)
  

⚡ How Feedfetcher Works #

• Requests feeds on behalf of the user
  
• Ignores robots.txt (because it acts like a direct user request, not a crawler)
  
• Stores & periodically refreshes feeds for efficiency
  
• Often shares the same retrieved feed with multiple users to save bandwidth
  

📈 Frequency of Retrieval #

• Usually ≤ 1 request per hour per feed
  
• Popular/frequently updated feeds may refresh more often
  
• Network delays can cause short bursts of requests
  

🚫 Blocking Feedfetcher #

Since robots.txt doesn’t work:

• Return HTTP status codes for Feedfetcher-Google requests:
  
  • 404 Not Found
    
  • 410 Gone
    
• If hosted on a platform (like Blogger, WordPress, etc.), configure restrictions through the platform settings
  

🔍 Why It Might Fetch “Odd” or “Secret” URLs #

• A user manually typed or bookmarked the feed URL
  
• A user shared the link
  
• Feedfetcher does not guess URLs—it only fetches the one explicitly provided
  

📊 Technical Details #

• Distributed across multiple machines → requests may come from different Google IPs
  
• IP ranges: Listed in user-triggered-fetchers-google.json
  
• Fetches exact URL only (does not follow links like Googlebot)
  

💡 FSIDM Tip for Students/Marketers:
If you run a podcast, news site, or blog:

• Ensure your RSS/Atom feeds are valid & clean (follow spec)
  
• Feedfetcher helps deliver your content faster to apps & news surfaces
  
• Don’t block it unless you have a business reason (e.g., premium content)