Search engine crawlers and AI bots may become either major traffic drivers or one of the largest sources of unnecessary server load. While legitimate bots like Googlebot and Bingbot improve indexing and search visibility, aggressive crawlers may consume excessive bandwidth, overload servers and negatively affect crawl budget efficiency.
The scale of automated traffic keeps growing. According to Imperva’s 2025 Bad Bot Report, automated traffic accounted for 51% of all web traffic, while bad bots made up 37% of all internet traffic.
In 2026, crawler management is no longer limited to traditional SEO. Website owners now also need to evaluate AI crawlers and retrieval bots that influence visibility in platforms like ChatGPT, Perplexity and AI-powered search systems.
This guide explains the difference between good and bad crawling bots, how to verify legitimate crawlers, which bots should be blocked or rate-limited and how to optimize crawler activity for SEO, AI visibility and server performance.
– Resource-heavy and AI crawlers often require rate limiting instead of complete blocking to balance crawl access and server performance.
– Malicious bots typically ignore robots.txt directives and should be blocked through server-level security, CDN or WAF protection.
What Is a Crawling Bot?
A crawling bot is an automated program that scans websites to discover, index, analyze or retrieve content. Crawling bots are commonly used by search engines, AI platforms, SEO tools and analytics systems.
Some crawlers improve website visibility and indexing, while others may consume server resources, scrape content or collect data for AI training systems.
Types of Web Crawlers in 2026
Modern websites are visited by many different types of crawlers. Some bots improve search visibility and content discovery, while others consume server resources, scrape content or collect data for AI systems.
| Crawler Type | Primary Purpose | Typical Recommendation |
|---|---|---|
| Search engine crawlers | Indexing and ranking | Allow |
| AI retrieval bots | AI-generated answers | Usually allow |
| AI training crawlers | Dataset collection | Depends |
| SEO crawlers | Analytics and backlinks | Rate-limit |
| Suspicious bots | Scraping and abuse | Block |
Each crawler category affects websites differently. Some bots improve indexing and discoverability, while others primarily consume infrastructure resources or collect data for AI systems and analytics platforms.
Search Engine Crawlers
Search engine crawlers are responsible for discovering, indexing and ranking website pages in search engines. Bots like Googlebot, Bingbot and YandexBot continuously analyze website content, internal links, structured data and page quality signals.
These crawlers are essential for SEO visibility and should generally always be allowed. Website owners should regularly monitor whether these crawlers can efficiently access important pages, XML sitemaps and updated content.
AI Crawlers and Retrieval Bots
AI crawlers are used by large language models, AI search engines and answer generation systems. Unlike traditional search bots, AI crawlers may process content for model training, retrieval augmentation and AI-generated answers.
Some AI bots focus on training datasets, while others retrieve live website content for conversational search experiences. In 2026, many websites evaluate AI crawlers not only from a server performance perspective, but also from an AI visibility and content licensing standpoint.
SEO and Analytics Crawlers
SEO crawlers belong to platforms like Ahrefs, Semrush, Moz and Majestic. These bots continuously scan websites to build backlink databases, keyword datasets and SEO analytics tools.
Although legitimate, these crawlers may generate large volumes of requests and consume additional server resources.
Malicious and Suspicious Bots
Malicious bots typically ignore robots.txt directives, spoof legitimate user-agents and perform scraping, spam automation, credential stuffing or vulnerability scanning.
Unlike search engine bots, these crawlers provide no SEO or visibility value and are usually blocked at the server or firewall level.
Good crawling bots👍
Good crawling bots are usually operated by legitimate search engines, AI retrieval systems and trusted content platforms. These crawlers help websites improve discoverability, indexing and content accessibility across both traditional and AI-driven search ecosystems.
Major Search Engine Crawlers
These crawlers are essential for technical SEO and organic traffic growth. Blocking them accidentally may lead to indexing problems, visibility loss and reduced crawl coverage in search engines.
These crawlers also influence how websites appear in AI-assisted search systems, rich snippets and conversational search experiences.
User-agent: Googlebot 👍
Googlebot is Google’s primary web crawler responsible for discovering, rendering and indexing website content in Google Search. The crawler continuously analyzes pages, internal links, structured data and technical SEO signals to update Google’s search index.
Googlebot also uses advanced JavaScript rendering to process dynamic websites, headless commerce storefronts and single-page applications.
User-agent: Bingbot 👍
Bingbot is Microsoft Bing’s crawler used for indexing websites across Bing Search and Microsoft AI-powered search systems. The crawler supports desktop and mobile indexing and plays an increasingly important role in AI-assisted search experiences.
Bingbot also powers indexing for Microsoft Copilot and other Microsoft AI-assisted search experiences.
User-agent: Slurp 👍
Yahoo Slurp is Yahoo’s search crawler used for indexing web content and collecting information for Yahoo Search and partner services including Yahoo News and Yahoo Finance.
Although Yahoo Search relies heavily on partner technologies today, Yahoo Slurp still appears in many crawl logs and continues indexing content for Yahoo ecosystem services.
User-agent: YandexBot 👍
YandexBot belongs to Yandex, one of the largest search engines in Eastern Europe and Central Asia. The crawler indexes website content, analyzes technical SEO signals and processes regional search results.
Yandex operates multiple specialized crawlers responsible for images, videos, news and other vertical search services.
User-agent: Baiduspider 👍
Baiduspider is Baidu’s web crawler used to index websites for the Chinese search market. Websites targeting Asian audiences should generally allow Baiduspider to improve regional visibility.
However, some website owners outside Asian markets restrict Baiduspider because of unnecessary crawl activity and limited regional business value.
Privacy and Alternative Search Bots
Alternative search engines and privacy-focused platforms continue growing in popularity in 2026. Their crawlers help websites appear in alternative search ecosystems, AI assistants and privacy-oriented discovery platforms.
User-agent: DuckDuckBot 👍
DuckDuckBot is the crawler used by DuckDuckGo, a privacy-focused search engine known for not tracking users. The bot helps index websites for DuckDuckGo search results and alternative search ecosystems.
User-agent: Applebot 👍
Applebot is Apple’s crawler used for Siri, Spotlight Suggestions and AI-powered search features across Apple devices and services.
User-agent: PetalBot 👍/👎
PetalBot belongs to Huawei’s Petal Search ecosystem and is used to crawl and index websites for mobile and AI-assisted search experiences.
Some website owners still rate-limit PetalBot because of aggressive crawl frequency on large websites.
Social Media and Preview Crawlers
Although these bots do not directly influence traditional SEO rankings, they affect how links appear across social media platforms. Proper metadata crawling improves click-through rates, content previews and social sharing visibility.
These crawlers are especially important for content marketing, media websites and businesses that rely heavily on social sharing traffic.
User-agent: FacebookBot 👍
FacebookBot crawls website pages to generate previews, metadata and Open Graph information for shared URLs across Facebook and Instagram.
User-agent: LinkedInBot 👍
LinkedInBot processes metadata, titles and preview information for links shared across LinkedIn feeds and business content.
AI Crawlers and AI Retrieval Bots 🤖
AI crawlers became one of the fastest-growing sources of crawler traffic in 2025–2026. These bots may affect AI-generated answers, conversational search visibility and referral traffic from AI platforms.
Cloudflare reported that AI and search crawler traffic grew by 18% from May 2024 to May 2025. GPTBot grew by 305% during the same period, while ChatGPT-User grew by 2,825%, showing how quickly AI-related crawling activity is expanding.
AI Training Crawlers
AI training crawlers collect publicly available data that may later be used for machine learning datasets and AI model development. Some publishers allow these bots to increase AI ecosystem visibility, while others restrict them to protect content and reduce infrastructure load.
These crawlers are often the primary target of AI blocking policies implemented by publishers and enterprise websites.
User-agent: GPTBot 🤖
GPTBot is OpenAI’s crawler used to collect publicly available content that may improve future AI models and AI-powered services. Website owners can choose whether to allow GPTBot depending on their AI visibility and content protection strategy.
User-agent: CCBot 🤖
CCBot is the crawler behind Common Crawl, one of the largest openly available web datasets widely used across the AI industry for language model training and research purposes.
User-agent: Bytespider 🤖
Bytespider is associated with ByteDance services and AI-related content discovery systems. The crawler is commonly used for large-scale data collection and AI ecosystem indexing.
AI Retrieval and Search Bots
Unlike training crawlers, retrieval bots access live website content to generate real-time AI answers and citations. These crawlers may contribute referral traffic and brand visibility from AI-powered search platforms.
These bots may also contribute citations and brand mentions inside AI-generated answers.
User-agent: ChatGPT-User 🤖
ChatGPT-User is OpenAI’s retrieval bot used to fetch live web content for ChatGPT browsing and AI-generated answers. Unlike GPTBot, it focuses on real-time content retrieval rather than AI model training.
User-agent: Perplexity-User 🤖
Perplexity-User retrieves live website content for citation-based answers and conversational search experiences inside Perplexity AI.
User-agent: Claude-SearchBot 🤖
Claude-SearchBot is Anthropic’s retrieval crawler used for AI search systems and real-time answer generation. The bot accesses publicly available web content to improve conversational search experiences.
AI Platform Crawlers
Some AI companies operate broader crawler infrastructures used for indexing, content analysis and AI ecosystem support beyond real-time retrieval.
These crawlers may perform indexing, metadata collection and large-scale content analysis across broader AI ecosystems.
User-agent: ClaudeBot 🤖
ClaudeBot is Anthropic’s broader AI crawler used for website content processing, AI system improvement and platform-level content analysis.
User-agent: PerplexityBot 🤖
PerplexityBot is Perplexity AI’s crawler responsible for indexing and processing website content for AI-generated answers and AI-assisted search systems.
User-agent: Amazonbot 🤖
Amazonbot is Amazon’s crawler used for indexing, content processing and AI-related services across Amazon ecosystems and cloud infrastructure.
Bad Crawling Bots 👎
Not all “bad” crawlers are malicious. Many belong to SEO platforms, AI systems or analytics services and are considered problematic mainly because of high crawl frequency, bandwidth consumption or limited business value for certain websites.
Resource-Heavy SEO Crawlers
These crawlers usually belong to legitimate SEO tools and analytics platforms. On small websites they rarely cause problems, but on large stores, marketplaces and media platforms they may consume significant crawl resources and bandwidth.
User-agent: AhrefsBot 👎
AhrefsBot is a large-scale SEO crawler used by the Ahrefs platform to collect backlink, keyword and technical SEO data. Although legitimate, the bot may generate intensive crawl activity and consume significant bandwidth on large websites.
User-agent: SEMrushBot 👎
SEMrushBot continuously scans websites to update SEO databases, keyword indexes and competitive analytics tools used by the Semrush platform. On high-traffic websites, the crawler may noticeably increase server load.
User-agent: MJ12Bot 👎
MJ12Bot belongs to Majestic, a backlink intelligence and SEO analytics platform. The crawler collects link graph data and continuously scans websites to maintain one of the industry’s largest backlink databases.
User-agent: DotBot 👎
DotBot is Moz’s crawler used to collect website and backlink data for Moz SEO tools and analytics services. The crawler may consume considerable crawl resources on large websites and marketplaces.
High-Frequency AI Crawlers
Some AI crawlers aggressively collect large amounts of website content for AI indexing and dataset generation. Their activity may significantly increase server load on content-heavy websites.
User-agent: GPTBot 👎
Although GPTBot belongs to a legitimate AI platform, some website owners classify it as a high-frequency crawler because of AI training concerns and infrastructure costs.
User-agent: CCBot 👎
CCBot is frequently associated with large-scale AI dataset collection and may generate intensive crawl activity on content-heavy websites.
User-agent: Bytespider 👎
Bytespider is widely reported by publishers and marketplace owners as one of the more aggressive large-scale AI crawlers.
Suspicious and Unverified Crawlers
Unlike legitimate search and AI crawlers, suspicious bots often ignore robots.txt directives, rotate IP addresses and imitate trusted user-agents.
User-agent: MauiBot 👎
MauiBot is an unidentified crawler frequently reported for aggressive scanning activity and excessive request volumes. Many website owners block the bot due to suspicious behavior and limited transparency.
User-agent: Fake Googlebot 👎
Fake Googlebot crawlers imitate legitimate Googlebot user-agents to bypass firewall rules and security systems. These bots are commonly associated with scraping, vulnerability scanning and abusive automation.
User-agent: Unknown Scrapers 👎
Some crawlers continuously rotate IP addresses, spoof user-agents and ignore robots.txt directives completely. These bots often perform automated scraping, spam generation or unauthorized data collection.
Which Crawlers Should You Allow, Limit or Block?
There is no universal crawler policy suitable for every website. News publishers, SaaS companies, online stores and AI-sensitive businesses often require different bot management strategies.
The best crawler policy depends on your business model, server infrastructure and content strategy. News publishers, SaaS companies and AI-sensitive websites often use very different bot management approaches.
| Crawler Type | Recommended Action | Typical Reason |
|---|---|---|
| Googlebot | Allow | SEO indexing |
| Bingbot | Allow | Search + AI visibility |
| ChatGPT-User | Usually allow | AI retrieval traffic |
| AhrefsBot | Rate-limit | Heavy crawl activity |
| GPTBot | Depends | AI training concerns |
| Fake Googlebot | Block | Malicious behavior |
Which Crawlers Should Always Be Allowed
Search engine crawlers like Googlebot and Bingbot should generally always be allowed because they directly affect website indexing and organic visibility.
Which Crawlers Should Be Rate-Limited
SEO crawlers and some AI bots may be rate-limited to reduce server load while still allowing controlled access.
Rate limiting is often more effective than complete blocking because it reduces server pressure while still allowing controlled crawler access.
Which Crawlers Should Be Blocked
Malicious bots, fake search engine crawlers and abusive scrapers are usually blocked at the firewall or server level.
Persistent abusive bots that ignore crawl directives, perform scraping or generate suspicious request patterns are usually blocked completely at the server or firewall level. Some publishers and enterprise websites block AI training crawlers to protect proprietary content, reduce infrastructure costs or limit AI dataset collection.
Signs Your Website Is Being Overcrawled
Excessive crawler activity may negatively affect server stability, crawl efficiency and website performance. Monitoring crawler behavior helps identify infrastructure problems before they affect indexing and user experience.
Without proper crawler management, excessive bot activity may eventually affect user experience, indexing speed and infrastructure costs.
Bandwidth and Server Performance Issues
Common signs include bandwidth spikes, increased CPU usage and slower response times during intensive crawl activity.
Excessive Crawl Requests
Thousands of requests from a single user-agent within short periods may indicate aggressive crawler behavior. This issue is especially common on websites with poorly configured filters, search pages or infinite URL combinations.
Reduced Crawl Efficiency
Overcrawling may waste crawl budget and prevent search engines from prioritizing important pages and updated content.
How to Verify Legitimate Crawlers
Some malicious bots pretend to be Googlebot or Bingbot to bypass firewall rules and security systems.
Verify Reverse DNS Records
Google and Bing officially recommend reverse DNS verification to confirm legitimate crawler ownership.
Check IP Ownership
Website owners should verify whether crawler IP addresses belong to official search engine infrastructures. Official search engines usually publish crawler IP verification documentation and ownership ranges.
Analyze Server Logs
Server logs help identify crawl frequency, suspicious request patterns and fake user-agents. Monitoring server logs regularly helps identify unexpected crawler spikes, fake bots and inefficient crawl behavior before they affect website stability.
Example of crawler activity in server logs, including search engine bots, SEO crawlers and suspicious requests.Detect Fake Googlebots and Bingbots
Fake search engine bots are commonly used for scraping, spam automation and vulnerability scanning. Fake bots often fail reverse DNS verification and generate suspicious crawl patterns that differ from legitimate search engine behavior.
How to Optimize Crawl Budget
Efficient crawl budget optimization helps search engines prioritize important pages and reduce unnecessary crawling activity.
Improve Internal Linking
Strong internal linking helps crawlers discover important pages faster and improves crawl efficiency. Poor internal linking may leave important pages orphaned and difficult for crawlers to discover efficiently.
Remove Duplicate and Low-Value Pages
Duplicate URLs, faceted navigation and thin pages may waste crawl budget and reduce indexing efficiency. Common examples include filtered URLs, session parameters, duplicate category pages and internal search result pages.
For example, eCommerce filters may generate thousands of duplicate URLs that waste crawl budget and reduce indexing efficiency.
Optimize XML Sitemaps
XML sitemaps help search engines discover updated pages faster and prioritize important content. Outdated or poorly maintained sitemaps may reduce crawl efficiency and slow down indexing of important pages.
Use Canonical Tags Correctly
Canonical tags help consolidate duplicate URLs and improve crawl prioritization. Incorrect canonicalization may confuse crawlers and waste crawl budget on duplicate or low-priority pages.
Optimize JavaScript Rendering
Modern crawlers increasingly rely on JavaScript rendering to process headless commerce websites, single-page applications and dynamically generated storefronts. This is especially important for headless commerce architectures where rendering optimization directly affects crawlability and indexing efficiency.
Poor JavaScript rendering optimization may prevent crawlers from properly indexing product pages, filters, navigation elements and dynamically generated content.
How to Control Crawlers
Modern crawler management combines robots.txt directives, rate limiting, server-level controls and infrastructure protection systems. The goal is not simply to block bots, but to balance SEO visibility, AI discoverability and server performance.
Control Crawlers with Robots.txt
Robots.txt remains the most common way to manage crawler access and crawling behavior. For example, website owners may block AI training crawlers while still allowing search engine bots and AI retrieval systems.
However, robots.txt only provides crawl instructions and does not guarantee that malicious bots will obey them.
Use Crawl-Delay Directive
The Crawl-delay directive helps reduce crawl frequency for bots that support it. Googlebot does not support Crawl-delay and must be managed through Google Search Console. Bingbot and some SEO crawlers still support Crawl-delay directives in certain scenarios.
Apply Server-Level Blocking
Persistent abusive crawlers that ignore robots.txt directives may require complete server-level blocking. Server-level restrictions are commonly configured through Apache, NGINX, Cloudflare or Web Application Firewall (WAF) rules.
Use Rate Limiting
Rate limiting helps reduce excessive crawl frequency without completely blocking legitimate bots. This approach is especially useful for SEO crawlers and AI bots that provide some visibility value but generate excessive request volumes. Unlike complete blocking, rate limiting reduces crawler activity without fully removing access for legitimate bots.
Protect Your Website with CDN and WAF
Platforms like Cloudflare, Fastly and Akamai help reduce unnecessary crawler traffic through bot detection, rate limiting and firewall protection. Modern CDN and WAF systems can automatically detect suspicious request patterns while preserving access for legitimate search engine crawlers.
The need for stronger bot protection is growing as AI bot activity increases. Akamai reported that, between July and August 2025, North America accounted for 54.9% of AI bot activity, followed by EMEA at 23.6% and APAC at 20.2%.
Common Crawl Management Mistakes
Many crawl management problems are caused not by bots themselves, but by poor technical SEO decisions and incorrect crawler policies. Misconfigured crawl settings may reduce indexing efficiency, increase server load and prevent important pages from appearing in search results and AI-generated answers.
The most common crawl management mistakes include:
- blocking legitimate search engine crawlers like Googlebot or Bingbot;
- ignoring crawl budget optimization on large websites;
- allowing infinite URL combinations generated by filters and faceted navigation;
- using outdated or incomplete XML sitemaps;
- failing to monitor server logs and crawler activity;
- blocking AI retrieval bots unintentionally;
- relying only on robots.txt for protection against malicious bots.
For example, eCommerce websites often generate thousands of filtered URLs that waste crawl budget and reduce indexing efficiency. At the same time, accidentally blocking AI retrieval bots may limit visibility in conversational search systems and AI-generated answers.
Regular crawl audits, log analysis and infrastructure monitoring help website owners identify these issues before they affect search visibility and server performance.
Conclusion
Crawler management is increasingly connected with Generative Engine Optimization (GEO) — the process of improving visibility in AI-generated answers and AI search platforms. Modern websites now optimize not only for search engine indexing, but also for AI retrieval systems, answer engines and conversational discovery platforms.
Managing crawling bots in 2026 requires balancing search engine indexing, AI crawler access, crawl budget optimization and server performance protection. Regular log analysis, bot verification, XML sitemap maintenance and proper robots.txt configuration help websites improve indexing efficiency without wasting infrastructure resources.
The most effective crawler strategy in 2026 is balancing SEO visibility, AI discoverability and server performance. Legitimate search engine crawlers should generally be allowed, resource-heavy bots often require rate limiting and malicious crawlers should typically be blocked at the server or firewall level.
FAQ About Crawling Bots
Can Blocking Bots Improve Website Speed?
Blocking aggressive crawlers may reduce bandwidth usage and improve server performance on overloaded websites.
Should I Block AI Crawlers?
Blocking AI crawlers may protect content and reduce server load, but it can also reduce visibility in AI-generated answers and conversational search systems.
What Is Crawl Budget?
Crawl budget is the amount of crawling resources search engines allocate to scanning and indexing your website.
How Do I Verify a Real Googlebot?
The most reliable method is reverse DNS verification combined with IP ownership checks.
Can Crawlers Increase Hosting Costs?
Aggressive crawlers may increase bandwidth usage, CPU load and infrastructure costs, especially on large websites and marketplaces.
eCommerce expert with 10+ years of experience in marketplace management and consumer behavior. Gayane tracks the latest industry trends to provide businesses with analytical, actionable insights.
