Web Crawler & Bot Reference Guide

Understanding the different bots (also called “crawlers” or “spiders”) that visit your website is essential for interpreting your crawl data effectively. These automated programs serve various purposes, from search engine indexing to AI training and social media previews.

Key Insight for 2025: AI crawlers now make up over 50% of web traffic on many sites. Some collect data for AI training (which you may want to block), while others fetch content when users ask AI assistants questions (which can drive referral traffic to your site).

🔍 Search Engine Crawlers

These bots index your pages so they appear in search results. Blocking them removes your site from their search engine.

Googlebot

Operator: Google

Detection Pattern: googlebot, google-structured-data-testing-tool

Purpose: Google’s primary web crawler that discovers and indexes content for Google Search. Operates in Desktop and Smartphone versions for mobile-first indexing.

Why Track: Directly impacts your Google Search visibility. Higher visit frequency indicates Google sees your content as important. Essential for SEO.

Recommendation: Always Allow

Bingbot

Operator: Microsoft

Detection Pattern: bingbot, msnbot, bingpreview

Purpose: Microsoft’s crawler for Bing search. Also powers Copilot features and Microsoft Edge suggestions. BingPreview generates page previews for search results.

Why Track: Essential for reaching Bing users. Powers Microsoft ecosystem integration including Edge, Cortana, and Office products.

Recommendation: Always Allow

DuckDuckBot

Operator: DuckDuckGo

Detection Pattern: duckduckbot, duckduckgo

Purpose: Crawls for DuckDuckGo’s privacy-focused search engine. No user tracking or data collection during crawling.

Why Track: Reach privacy-conscious users. Growing user base makes this increasingly important for traffic diversification.

Recommendation: Recommended

YandexBot

Operator: Yandex

Detection Pattern: yandexbot, yandex

Purpose: Russia’s leading search engine crawler. Optimized for Russian-language content and Cyrillic text processing.

Why Track: Essential for reaching Russian-speaking audiences and Eastern European markets.

Recommendation: Regional (Allow if targeting these markets)

Baiduspider

Operator: Baidu

Detection Pattern: baiduspider, baidu

Purpose: China’s dominant search engine crawler. Focuses on Chinese-language content with special handling for simplified Chinese characters.

Why Track: Crucial for visibility in China’s massive digital market. Required for Chinese audience reach.

Recommendation: Regional (Allow if targeting China)

Yahoo Slurp

Operator: Yahoo

Detection Pattern: slurp, yahoo

Purpose: Historically Yahoo’s primary crawler. Yahoo search now largely uses Bing’s index, but Slurp still handles specific Yahoo services.

Why Track: Some Yahoo properties still use independent crawling. Powers certain Yahoo-specific features.

Recommendation: Optional

Applebot

Operator: Apple

Detection Pattern: applebot

Purpose: Crawls for Apple’s ecosystem including Siri suggestions, Spotlight search, and Safari’s intelligent features. Separate from Applebot-Extended.

Why Track: Optimize for Siri voice search and iOS device integration. Important for Apple ecosystem users.

Recommendation: Recommended

Sogou Spider

Operator: Sogou (Tencent)

Detection Pattern: sogou

Purpose: Chinese search engine owned by Tencent. Popular in China as an alternative to Baidu.

Why Track: Additional reach in Chinese market. Integrated with Tencent’s ecosystem including WeChat.

Recommendation: Regional (Allow if targeting China)

PetalBot

Operator: Huawei

Detection Pattern: petalbot

Purpose: Huawei’s search engine crawler for Petal Search, used on Huawei devices without Google services.

Why Track: Important for reaching Huawei device users, particularly in markets where Google services are unavailable.

Recommendation: Regional

🤖 AI Training Crawlers

These bots collect content to train AI/LLM models. Blocking them will NOT affect your search rankings.

Important: You can block all AI training bots via robots.txt without any negative impact on your Google, Bing, or other search engine visibility. This is a personal/business choice about whether you want your content used for AI training.

GPTBot

Operator: OpenAI

Detection Pattern: gptbot

Purpose: OpenAI’s crawler that collects data to train GPT models (ChatGPT, GPT-4, etc.). The highest-volume AI crawler, accounting for approximately 30% of all AI bot traffic.

Why Track: Monitor AI training data collection. Highest volume means potential server impact. Respects robots.txt.

Recommendation: Your Choice (Safe to block)

Google-Extended

Operator: Google

Detection Pattern: google-extended

Purpose: Collects training data for Google’s Gemini AI models. Completely separate from Googlebot – blocking this does NOT affect Google Search indexing.

Why Track: Control whether Google uses your content for Gemini AI training. Safe to block without SEO impact.

Recommendation: Your Choice (Safe to block)

ClaudeBot

Operator: Anthropic

Detection Pattern: claudebot

Purpose: Anthropic’s crawler for training Claude AI models. Respects robots.txt directives.

Why Track: Monitor Anthropic’s data collection for Claude training. Medium traffic volume.

Recommendation: Your Choice (Safe to block)

Meta-ExternalAgent

Operator: Meta (Facebook)

Detection Pattern: meta-externalagent

Purpose: Meta’s crawler for training Llama AI models. Very high volume – accounts for approximately 19% of AI crawler traffic.

Why Track: One of the most aggressive AI training crawlers. High server load potential. Different from Facebook’s social preview bot.

Recommendation: Your Choice (Safe to block)

PerplexityBot

Operator: Perplexity AI

Detection Pattern: perplexitybot

Purpose: Crawls for Perplexity’s AI search engine. The fastest-growing AI crawler with 157,000%+ growth in 2024.

Why Track: Rapidly increasing presence. High growth trajectory means increasing server requests over time.

Recommendation: Your Choice (Safe to block)

CCBot

Operator: Common Crawl Foundation

Detection Pattern: ccbot

Purpose: Creates open datasets used by many AI companies and researchers for training models. Non-profit organization.

Why Track: Data ends up in many AI systems indirectly. Blocking prevents broad AI training data collection.

Recommendation: Your Choice (Safe to block)

Bytespider

Operator: ByteDance (TikTok)

Detection Pattern: bytespider

Purpose: TikTok parent company’s AI crawler. Activity has been declining recently.

Why Track: Track ByteDance data collection. Currently showing declining traffic patterns.

Recommendation: Your Choice (Safe to block)

Grok

Operator: xAI (Elon Musk)

Detection Pattern: grok

Purpose: Powers Grok AI chatbot with real-time web access. Has special integration with X (Twitter).

Why Track: Monitor xAI data collection. Low to medium traffic volume currently.

Recommendation: Your Choice (Safe to block)

Cohere-AI

Operator: Cohere

Detection Pattern: cohere-ai

Purpose: Enterprise AI company’s crawler for training language models focused on business applications.

Why Track: Track enterprise AI data collection. Lower volume than consumer AI crawlers.

Recommendation: Your Choice (Safe to block)

AI2Bot

Operator: Allen Institute for AI

Detection Pattern: ai2bot

Purpose: Non-profit AI research organization’s crawler. Data used for academic AI research.

Why Track: Academic/research focused. Generally lower impact than commercial AI crawlers.

Recommendation: Your Choice (Safe to block)

Diffbot

Operator: Diffbot

Detection Pattern: diffbot

Purpose: AI-powered web scraping and knowledge graph building. Used by enterprises for data extraction.

Why Track: Commercial data extraction service. May be accessing your content for client projects.

Recommendation: Your Choice (Safe to block)

Applebot-Extended

Operator: Apple

Detection Pattern: applebot-extended

Purpose: Apple’s AI training crawler, separate from regular Applebot. Used for Apple Intelligence features.

Why Track: Different from regular Applebot. Safe to block without affecting Siri or Spotlight.

Recommendation: Your Choice (Safe to block)

Amazonbot

Operator: Amazon

Detection Pattern: amazonbot

Purpose: Amazon’s crawler for Alexa answers and AI training. Used to improve Alexa’s knowledge base.

Why Track: Powers Alexa voice responses. Blocking may affect how Alexa answers questions about your content.

Recommendation: Your Choice

YouBot

Operator: You.com

Detection Pattern: youbot

Purpose: AI search engine You.com’s crawler for indexing and AI training.

Why Track: Smaller AI search player. Lower traffic volume.

Recommendation: Your Choice (Safe to block)

Omgilibot

Operator: Omgili/Webz.io

Detection Pattern: omgili

Purpose: Data collection crawler that powers news and social media monitoring services.

Why Track: Commercial data aggregation. Content may appear in news monitoring products.

Recommendation: Your Choice (Safe to block)

💬 AI Assistant Crawlers (User-Triggered)

These bots fetch pages when real users ask AI assistants questions. They can drive referral traffic when AI cites your content.

Recommendation: Consider ALLOWING these bots. Unlike training crawlers, these represent actual users seeking information. When AI assistants cite your content, users may click through to your site.

ChatGPT-User

Operator: OpenAI

Detection Pattern: chatgpt-user

Purpose: Fetches pages in real-time when ChatGPT users ask questions. Enables ChatGPT’s web browsing feature. Shows 2,825%+ growth in 2024.

Why Track: Your content may be directly quoted in ChatGPT responses with attribution. High referral potential.

Recommendation: Consider Allowing (Can drive traffic)

OAI-SearchBot

Operator: OpenAI

Detection Pattern: oai-searchbot

Purpose: OpenAI’s dedicated search crawler for ChatGPT’s search feature. Separate from GPTBot training crawler.

Why Track: Powers ChatGPT search results. Can drive traffic when users explore cited sources.

Recommendation: Consider Allowing (Can drive traffic)

Claude-User

Operator: Anthropic

Detection Pattern: claude-user

Purpose: Fetches web content when Claude users request current information. Enables Claude’s web search capabilities.

Why Track: Real users asking Claude questions. Potential for content citation and referral traffic.

Recommendation: Consider Allowing (Can drive traffic)

Perplexity-User

Operator: Perplexity AI

Detection Pattern: perplexity-user

Purpose: Fetches pages for Perplexity AI search answers. Note: Has been known to sometimes ignore robots.txt.

Why Track: High referral potential – Perplexity shows sources prominently. May not fully respect robots.txt.

Recommendation: Consider Allowing (High referral potential)

📱 Social Media Crawlers

These bots generate link previews when your URLs are shared on social media. Blocking them breaks your link previews.

facebookexternalhit

Operator: Meta

Detection Pattern: facebookexternalhit, facebot

Purpose: Generates link previews for Facebook, Instagram, Messenger, and WhatsApp. Reads Open Graph metadata for titles, descriptions, and images.

Why Track: Essential for social media marketing. Broken previews significantly reduce engagement and click-through rates.

Recommendation: Always Allow

Twitterbot

Operator: X (Twitter)

Detection Pattern: twitterbot

Purpose: Creates Twitter/X card previews when links are shared. Reads Twitter Card metadata.

Why Track: Essential for X/Twitter engagement. Card previews drive significantly more clicks than plain links.

Recommendation: Always Allow

LinkedInBot

Operator: LinkedIn

Detection Pattern: linkedinbot

Purpose: Generates link previews for LinkedIn posts and messages. Important for B2B and professional content.

Why Track: Critical for business and professional content sharing. LinkedIn is key for B2B marketing.

Recommendation: Always Allow

Pinterest

Operator: Pinterest

Detection Pattern: pinterest, pinterestbot

Purpose: Indexes images for Pinterest’s visual discovery platform. Enables Rich Pins with real-time information.

Why Track: Essential for visual content and e-commerce. Pinterest can drive significant referral traffic.

Recommendation: Always Allow

Slackbot

Operator: Slack (Salesforce)

Detection Pattern: slackbot

Purpose: Generates link previews in Slack workspaces when URLs are shared in channels or messages.

Why Track: Important for B2B. Links shared in work conversations benefit from rich previews.

Recommendation: Recommended

Discordbot

Operator: Discord

Detection Pattern: discordbot

Purpose: Creates link previews in Discord servers and direct messages.

Why Track: Important for community engagement. Discord has millions of active communities.

Recommendation: Recommended

TelegramBot

Operator: Telegram

Detection Pattern: telegrambot

Purpose: Generates link previews for Telegram chats and channels.

Why Track: Growing messaging platform. Important for international audiences.

Recommendation: Recommended

WhatsApp

Operator: Meta

Detection Pattern: whatsapp

Purpose: Creates link previews in WhatsApp messages. Part of Meta’s family of apps.

Why Track: Massive user base globally. Link previews important for sharing.

Recommendation: Always Allow

📊 SEO Tool Crawlers

These commercial bots gather data for SEO analysis tools. Generally safe to allow, but can be resource-intensive on some sites.

AhrefsBot

Operator: Ahrefs

Detection Pattern: ahrefsbot, ahrefs

Purpose: Builds Ahrefs’ comprehensive backlink database. Powers backlink analysis, keyword research, and site audits. Very high crawl volume.

Why Track: Influences your metrics in Ahrefs tools. Can be resource-intensive – one of the most active SEO crawlers.

Recommendation: Allow (Consider rate-limiting if needed)

SemrushBot

Operator: Semrush

Detection Pattern: semrushbot, semrush

Purpose: Gathers data for Semrush’s SEO platform including site audits, keyword tracking, and competitive analysis.

Why Track: Powers Semrush metrics and competitive intelligence. High crawl activity.

Recommendation: Allow (Consider rate-limiting if needed)

MJ12bot

Operator: Majestic

Detection Pattern: mj12bot, majestic

Purpose: Creates Majestic’s link index. Powers Trust Flow, Citation Flow, and other link authority metrics.

Why Track: Influences Trust Flow and Citation Flow scores. Medium crawl volume.

Recommendation: Allow

DotBot

Operator: Moz

Detection Pattern: dotbot, moz, opensiteexplorer

Purpose: Crawls for Moz’s Link Explorer. Calculates Domain Authority and Page Authority scores.

Why Track: Domain Authority is a widely-used SEO metric. Lower crawl volume than Ahrefs/Semrush.

Recommendation: Allow

Rogerbot

Operator: Moz

Detection Pattern: rogerbot

Purpose: Another Moz crawler used for their SEO tools and research.

Why Track: Supplements DotBot data collection. Low to medium volume.

Recommendation: Allow

Screaming Frog

Operator: Screaming Frog Ltd

Detection Pattern: screaming frog

Purpose: Popular desktop SEO crawler. Often used by SEO professionals to audit sites.

Why Track: Usually indicates someone is analyzing your site for SEO purposes (could be your own team or competitors).

Recommendation: Allow

SEOkicks

Operator: SEOkicks

Detection Pattern: seokicks

Purpose: German SEO tool crawler for backlink analysis.

Why Track: Regional SEO tool. Lower volume.

Recommendation: Allow

SISTRIX

Operator: SISTRIX

Detection Pattern: sistrix

Purpose: European SEO tool crawler, particularly popular in Germany.

Why Track: Powers SISTRIX visibility index. Important for European markets.

Recommendation: Allow

SerpstatBot

Operator: Serpstat

Detection Pattern: serpstatbot

Purpose: SEO platform crawler for keyword research and site analysis.

Why Track: Growing SEO tool. Moderate crawl volume.

Recommendation: Allow

Quick robots.txt Reference

Here are ready-to-use robots.txt snippets for common scenarios:

Block AI Training Bots

Add this to your robots.txt to prevent AI companies from using your content for training:

User-agent: GPTBot Disallow: / User-agent: Google-Extended Disallow: / User-agent: ClaudeBot Disallow: / User-agent: CCBot Disallow: / User-agent: meta-externalagent Disallow: / User-agent: PerplexityBot Disallow: /

Allow AI Assistant Bots (for referral traffic)

These bots can send traffic to your site when AI cites your content:

User-agent: ChatGPT-User Allow: / User-agent: Claude-User Allow: / User-agent: Perplexity-User Allow: / User-agent: OAI-SearchBot Allow: /

Note: Not all bots respect robots.txt. For stronger control, use server-level blocking via .htaccess rules or a Web Application Firewall (WAF).

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This reference is part of Linkilo’s Crawler Analyzer feature.