AI & MLData CollectionInfrastructure
22 min read

AI Training Data Collection
with Proxies

Large language models are trained on web-scale data, and the companies building them have become the largest consumers of crawling infrastructure on the internet. This guide covers the full pipeline from crawling to training, the tools powering AI data collection, and why mobile proxies deliver the highest data yield per dollar.

Billions
Pages Crawled for LLMs
Diverse
IP Fingerprints Needed
IETF
New AI Crawl Standards
10x
Enterprise Demand Growth

AI's Insatiable Appetite for Web Data

Every major large language model—GPT-4, Claude, Gemini, Llama, Mistral—is trained on data crawled from the open web. The scale is staggering: GPT-3 was trained on roughly 300 billion tokens drawn from approximately 45 terabytes of text. GPT-4 and its successors use datasets orders of magnitude larger. The Common Crawl project, which many AI labs use as a starting corpus, contains over 250 billion web pages accumulated over more than a decade.

But raw volume is only part of the story. AI companies need fresh data. Models trained on stale corpora produce outdated answers, miss recent events, and fail to understand evolving language patterns. This is why AI labs do not simply download Common Crawl once and call it done. They run continuous crawling operations that fetch new and updated pages daily, feeding this fresh data into ongoing pre-training and fine-tuning runs.

The result is that AI companies have become the largest new consumers of web crawling infrastructure. According to industry analyses, AI-related crawling now accounts for a significant and growing share of all bot traffic on the internet. Cloudflare, Akamai, and other CDN providers have reported measurable increases in crawler traffic attributable to AI data collection operations.

Why Fresh Data Matters

Knowledge Recency

Models need current information to answer questions about recent events, products, regulations, and cultural shifts. A model trained only on 2023 data cannot answer questions about 2026.

Language Evolution

New terminology, slang, technical jargon, and communication patterns emerge constantly. Fresh crawls capture how humans actually write and speak today.

Reducing Hallucination

Models fine-tuned on recent, accurate data hallucinate less frequently. Stale training data leads to confidently stated but factually wrong outputs.

Competitive Advantage

The lab with the freshest, highest-quality training data produces the best model. Data freshness is a direct competitive moat in the AI industry.

This demand is not slowing down. As models grow larger and multimodal capabilities expand, the appetite for diverse web data—text, images, code, structured data, multilingual content—continues to accelerate. For the infrastructure that supports this crawling, particularly proxy networks, the AI training data market represents the fastest-growing demand segment.

The Training Data Pipeline

Training an LLM is not as simple as pointing a crawler at the internet and feeding the results into a model. The data goes through a multi-stage pipeline where each step transforms raw web content into something suitable for training. Understanding where proxies fit in this pipeline explains why they are so critical to the entire operation.

  AI Training Data Pipeline
  ==========================

  +------------------+     +------------------+     +------------------+
  |                  |     |                  |     |                  |
  |    CRAWLING      |---->|    CLEANING      |---->|  DEDUPLICATION   |
  |                  |     |                  |     |                  |
  |  Fetch raw HTML  |     |  Strip boiler-   |     |  Remove exact &  |
  |  from millions   |     |  plate, ads,     |     |  near-duplicate  |
  |  of web pages    |     |  navigation      |     |  documents       |
  |                  |     |                  |     |                  |
  +--------+---------+     +------------------+     +--------+---------+
           |                                                 |
    [PROXIES HERE]                                           v
    Mobile IPs for                                  +------------------+
    high success rate                               |                  |
    Geo-distributed                                 |    FILTERING     |
    for diverse data                                |                  |
                                                    |  Quality scores  |
           +----------------------------------------|  Toxicity filter |
           |                                        |  PII removal     |
           v                                        |                  |
  +------------------+                              +--------+---------+
  |                  |                                       |
  |    TRAINING      |<--------------------------------------+
  |                  |
  |  Tokenize and    |
  |  train on GPU    |
  |  clusters        |
  |                  |
  +------------------+
Step 1

Crawling

Distribute requests across thousands of IPs to fetch raw HTML, APIs, and rendered pages from target domains at scale.

Proxy role: Proxies distribute requests across IPs and geographies to avoid blocks.

Step 2

Cleaning

Strip navigation, ads, boilerplate, and scripts. Extract meaningful text content and metadata from raw HTML.

Proxy role: Not directly involved, but cleaner data upstream reduces wasted bandwidth.

Step 3

Deduplication

Remove exact and near-duplicate pages using MinHash, SimHash, or suffix arrays. Training on duplicates wastes compute and biases models.

Proxy role: Not directly involved. Dedup runs on the cleaned corpus.

Step 4

Filtering

Apply quality classifiers, toxicity filters, PII removal, and domain-specific heuristics to select high-quality training samples.

Proxy role: Not directly involved. Filtering is a post-processing step.

Step 5

Training

Tokenize the filtered corpus and feed it into the model. Pre-training on trillions of tokens, fine-tuning on curated sets.

Proxy role: Not involved. Training happens on GPU clusters with the processed dataset.

The key takeaway is that proxies are the foundation of the entire pipeline. If the crawling step fails—because IPs get blocked, requests get rate-limited, or geographic coverage is insufficient—every downstream step suffers. Poor crawling yields incomplete data, which means the model trains on a biased or sparse view of the web. This is why AI companies invest heavily in proxy infrastructure, and why the quality of that infrastructure directly impacts model quality.

Why AI Crawlers Get Blocked

The tension between AI companies and website owners is one of the defining conflicts of the current AI era. Website publishers invest in creating content, and AI companies crawl that content to train models that may reduce the need for users to visit those sites. This has led to an arms race where websites increasingly block AI crawlers, and AI companies increasingly need sophisticated proxy infrastructure to maintain data access.

Why Sites Block AI Crawlers

  • High request volume: AI crawlers fetch millions of pages per day, consuming bandwidth and server resources far beyond normal traffic.
  • Pattern detection: Anti-bot systems identify crawler signatures through request timing, header patterns, and behavioral analysis.
  • robots.txt AI directives: Many sites now include specific User-Agent blocks for GPTBot, ClaudeBot, and other AI crawlers in their robots.txt.
  • Commercial protection: Publishers do not want their content used to train competing AI products without compensation.

How Proxies Address Each Block

  • IP rotation: Distribute requests across thousands of IPs so no single address exceeds rate limits.
  • Mobile fingerprints: Real 4G/5G IPs carry legitimate carrier fingerprints that anti-bot systems trust.
  • Geo-distribution: Crawl from IPs in 15+ countries, appearing as organic global traffic.
  • Request pacing: Smart rotation with natural timing patterns avoids behavioral detection.

The robots.txt Shift

As of 2026, an increasing number of major websites have added AI-specific directives to their robots.txt files. The New York Times, Reddit, Stack Overflow, and hundreds of other publishers now explicitly disallow GPTBot, CCBot, ClaudeBot, and similar AI crawler user-agents. This is separate from blocking general web scrapers—these sites specifically target AI training crawlers while still allowing search engine indexing. The IETF is actively developing formalized standards for AI-specific crawling directives to bring consistency to this rapidly evolving area.

It is important to note that using proxies does not bypass robots.txt or legal restrictions. Proxies solve the technical problem of IP-based blocking and rate limiting. Responsible AI data collection still requires checking and respecting robots.txt, honoring crawl-delay directives, and complying with applicable laws.

Proxy Requirements for AI Data Collection

Not all proxy infrastructure is created equal, and AI data collection places specific demands that differ from general web scraping. The scale, diversity, and continuity requirements of training data pipelines mean that proxy networks must meet a higher bar across multiple dimensions.

IP Diversity

Critical

Need IPs from many countries, carriers, and ASNs. Websites detect and block crawlers that use IPs from a single subnet or provider.

High Throughput

Critical

AI data collection involves millions of requests per day. Proxies must handle high concurrent connections without degradation.

Consistent Uptime

Critical

Data pipelines run continuously. Proxy downtime means gaps in your dataset, missed pages, and wasted compute reprocessing failures.

Geo-Distribution

High

Training data should represent diverse perspectives. Proxies in 15+ countries ensure you crawl localized content from different regions.

Rotation Control

High

Automatic IP rotation per request to distribute load. Sticky sessions for multi-page crawls that require session continuity.

Authentication

Medium

Username/password or IP whitelist authentication. API access for programmatic proxy management and monitoring.

Industry Positioning

The proxy industry is repositioning around AI demand. Bright Data has rebranded its marketing around “data infrastructure for AI,” Oxylabs promotes “LLM-ready data solutions,” and Scrapfly markets itself as a “web data platform for AI pipelines.” This shift reflects the reality that AI data collection is now the fastest-growing use case for proxy infrastructure.

At Proxies.sx, our mobile proxy network is purpose-built for the high-throughput, geo-distributed, always-on requirements that AI data pipelines demand. Real 4G/5G IPs across 15+ countries with carrier-grade rotation provide the IP diversity and trust level that AI crawling requires.

Mobile Proxies for AI Crawling

Among all proxy types—datacenter, residential, ISP, and mobile—mobile proxies offer the strongest combination of advantages for AI training data collection. The reasons are rooted in how mobile networks work and how anti-bot systems evaluate traffic.

Highest Trust Level

Mobile IPs are shared via Carrier-Grade NAT (CGNAT) among thousands of real users on the same cell tower. Websites cannot block these IPs without blocking legitimate customers, so they assign them the highest trust scores in their anti-bot systems.

Diverse Geographic Coverage

Mobile proxies from 15+ countries across multiple carriers provide genuinely diverse geographic fingerprints. This diversity is essential for collecting training data that represents global perspectives and localized content variants.

Carrier-Grade Rotation

Automatic IP rotation through real carrier infrastructure means each request can come from a different mobile IP. This natural rotation pattern looks identical to normal mobile user behavior, avoiding rate limits and behavioral flags.

Lower Block Rates = More Data Per Dollar

40-60%
Datacenter Success Rate
At $1/GB, effective cost per successful request: $1.67-2.50/GB
75-85%
Residential Success Rate
At $8/GB, effective cost per successful request: $9.41-10.67/GB
85-95%
Mobile Success Rate
At $4-6/GB, effective cost per successful request: $4.21-7.06/GB

* Effective cost accounts for wasted bandwidth on blocked/failed requests. Mobile proxies deliver more usable data per GB purchased.

The economics are clear when you factor in success rates. While mobile proxies have a higher per-GB sticker price than datacenter proxies, they waste far less bandwidth on blocked requests. For AI data collection where every page of training data matters, the higher success rate means mobile proxies often deliver the best cost-per-useful-page ratio, especially on protected sites.

For teams running continuous AI crawling pipelines, the volume pricing at Proxies.sx (down to $4/GB at 501-1000GB) makes mobile proxies particularly competitive for large-scale data collection operations where reliability and data quality are paramount.

Tools & Frameworks

A growing ecosystem of crawling tools has emerged specifically designed for AI data collection. These tools focus on converting web pages into clean, structured formats that LLMs can consume directly—markdown, JSON, or plain text stripped of HTML boilerplate. Here are the leading frameworks and how to integrate mobile proxies with each.

GPT Crawler

TypeScript18K+ stars

Custom GPT knowledge bases, small-to-medium corpora

Open-source crawler by Builder.io that generates knowledge files for custom GPTs. Outputs JSON ready for fine-tuning or RAG pipelines.

Proxy Integration

Set HTTP_PROXY / HTTPS_PROXY environment variables. GPT Crawler uses Playwright under the hood, which respects proxy env vars.

Firecrawl

TypeScript / Python SDK25K+ stars

Production LLM pipelines, RAG, structured extraction

API-first web crawler that converts pages to clean LLM-ready markdown. Handles JavaScript rendering, extracts structured data, and supports batch crawling.

Proxy Integration

Self-hosted: configure proxy in the Playwright launch options. Cloud: built-in proxy rotation. For mobile IPs, pass proxy credentials in the API config.

Crawl4AI

Python35K+ stars

AI researchers, RAG pipelines, async batch crawling

Open-source Python crawler purpose-built for LLM data. Async architecture, built-in chunking strategies, and cosine similarity filtering.

Proxy Integration

Pass proxy URL directly in the AsyncWebCrawler constructor. Supports HTTP, SOCKS5, and authenticated proxies including mobile.

Spider.cloud

Rust / Python SDK10K+ stars

High-throughput enterprise crawling, speed-critical pipelines

High-performance web crawler built in Rust. Converts any website to LLM-ready data with automatic JS rendering, anti-bot handling, and parallel crawling.

Proxy Integration

API-based: configure proxy settings per request via the API. Self-hosted: set proxy rotation at the configuration level.

Apify

JavaScript / Python

Enterprise data pipelines, managed scraping, pre-built extractors

Full-stack web scraping and automation platform. Offers pre-built actors for hundreds of websites, serverless compute, and managed proxy infrastructure.

Proxy Integration

Built-in proxy management with datacenter, residential, and custom proxy support. Add mobile proxies via the ProxyConfiguration class with custom URLs.

python
# Example: Crawl4AI with Proxies.sx mobile proxies
from crawl4ai import AsyncWebCrawler

async def crawl_for_training_data():
    proxy_url = "http://USER:PASS@proxy.proxies.sx:PORT"

    async with AsyncWebCrawler(
        proxy=proxy_url,
        headless=True,
    ) as crawler:
        result = await crawler.arun(
            url="https://example.com/article",
            # Output clean markdown for LLM training
            word_count_threshold=50,
            remove_overlay_elements=True,
        )

        # result.markdown contains clean LLM-ready text
        training_text = result.markdown
        print(f"Extracted {len(training_text)} chars")

All of these tools work with mobile proxies from Proxies.sx. The integration is typically a one-line configuration change: pass your proxy credentials to the crawler, and all requests are automatically routed through mobile IPs with rotation. Check our documentation for detailed setup instructions for each framework.

Legal & Ethical Considerations

AI training data collection operates in a rapidly evolving legal and ethical landscape. The question of who can crawl what, for what purpose, and under what conditions is being actively litigated in courts and debated in standards bodies. Teams building AI data pipelines must stay informed about these developments.

IETF AI Crawling Standards

The Internet Engineering Task Force (IETF) is developing new standards to address AI-specific web crawling. These standards aim to extend the existing robots.txt protocol with explicit directives for AI training data collection, separate from search engine indexing. Key proposals include:

  • AI-specific User-Agent classes: Formalized categories for AI training crawlers, distinguishing them from search engine bots.
  • Granular opt-out mechanisms: Allow site owners to permit indexing while blocking training data collection, or vice versa.
  • Machine-readable licensing: Standardized metadata that specifies the terms under which content can be used for AI training.
  • Rate limiting directives: Standardized crawl-delay and request-rate fields specific to AI crawlers.

Active Legal Cases

  • NYT v. OpenAI/Microsoft: Testing whether training on copyrighted news articles constitutes fair use.
  • Getty Images v. Stability AI: Whether image-to-image AI training infringes on photographer copyrights.
  • Authors Guild v. OpenAI: Class action on behalf of authors whose books were used for training.

Regulatory Developments

  • EU AI Act: Requires transparency about training data sources and compliance with copyright opt-out mechanisms.
  • Japan: Broad exception for AI training under copyright law, one of the most permissive frameworks globally.
  • US: No federal AI training data law yet. Relying on existing copyright and CFAA case law.

Responsible Crawling Best Practices

Respect robots.txt: Check and honor robots.txt directives for your crawler's User-Agent, including AI-specific disallow rules.
Honor crawl delays: Implement the Crawl-delay directive and add reasonable pauses between requests to the same domain.
Identify your crawler: Use a descriptive User-Agent string that identifies your organization and provides a contact URL.
Avoid PII: Filter out personally identifiable information from crawled data before it enters your training pipeline.
Provide opt-out: Offer a mechanism for site owners to request exclusion from your training dataset.
Document your sources: Maintain records of which domains were crawled and when, for compliance and reproducibility.

Frequently Asked Questions

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