Analysis

Does Web Scraping Make AI Hallucinations Worse?

Web scraping systematically degrades AI answer quality through context bloat, retrieval noise, and structural misalignment. Research shows scraped webpages increase hallucinations and reduce accuracy.

By Ioannis Bakagiannis · Founder & CEO · December 11, 2025

TL;DR

Yes and the research proves it. Web scraping doesn't just cost money or create legal risk. It systematically degrades answer quality in measurable, research-proven ways that increase hallucinations and reduce accuracy.

Key Finding

Language model performance degrades significantly when context grows, is noisy and the relevant information is positioned in the middle.

The Context Bloat Problem: Why More Isn't Better

The Overconsumption Problem

When you scrape a news article, you're not just paying for inefficient extraction—you're paying for massive overconsumption. You ingest entire articles when you only need specific facts, definitions, or relevant excerpts.

User asks: "What is the capital of France?"
  • Needed tokens: ~10-20
  • Ingested tokens: ~1,200
  • Waste: 98%

You're asking your AI system to find 150 tokens of signal among 1,200 tokens of irrelevant noise. And research shows this doesn't just waste tokens—it actively degrades performance.

The "Lost in the Middle" Problem: Why HTML Structure Kills Retrieval

Stanford researchers tested language models with multi-document question answering, systematically varying the position of relevant information within context windows (Liu et al., 2023).

Critical Research Finding

Performance is highest when relevant information occurs at the beginning or end of input context, and significantly degrades when models must access information in the middle of long contexts.

This held true even for models explicitly designed for long-context use.

Now consider the structure of scraped HTML:

Where Information Lives in Scraped HTML

FeaturePositionContent Type
BeginningFirst 20%Navigation, headers, boilerplate (NOISE)
Middle40-60%Actual article content (SIGNAL)
EndLast 20%Comments, footer, links (NOISE)

Even if there is extensive post-processing, you're placing the signal exactly where the model performs worst.

Structured content formats (JSON, Markdown, clean text) allow you to place the most relevant information at the beginning of the context window—where models excel at retrieval. Scraped HTML locks you into a structure optimized for human browsing, not AI retrieval.

Scraped HTML
20-30%
Performance Degradation
Structured Content
15-30%
Performance Improvement
45-60% better retrieval

Context Rot: How Token Count Degrades Recall

As token count increases in your context window, the model's ability to accurately recall and use information decreases—a phenomenon sometimes called "context rot."

Research on RAG robustness documents that:

Translation: Adding more context doesn't always help. Past a certain threshold, noisy context makes performance worse than no context at all.

The Catch-22

You need diverse sources for complete answers, but each additional scraped page adds exponential noise. Quality suffers whether you use too little context (incomplete answers) or too much (noise overwhelms signal).

RAG Performance Degradation from Retrieval Noise

How Noisy Context Triggers Hallucinations

Conventional wisdom says providing more context reduces hallucinations. But research shows the relationship is more nuanced—noisy, irrelevant context can make hallucinations worse, not better.

A comprehensive survey on hallucinations in large language models identified hallucination types:

Types of AI Hallucinations in RAG Systems

Distribution of hallucination types across research studies

Recent research demonstrates a direct, measurable relationship between context length with low signal-to-noise ratio and hallucination rates.

Critical Research Finding

The hallucination rate increases with context length, reaching approximately 45% when context approaches 2,000 tokens.

This isn't theoretical—it's a measured phenomenon across multiple studies.

Hallucination Rate vs. Context Length

How hallucination probability increases with context bloat

Research on RAG systems reveals that models get "distracted" by irrelevant content in documents, particularly in long documents where the answer isn't obvious. When retrieval granularity is too large, retrieved blocks contain excessive irrelevant content, increasing the cognitive burden on models and causing answers to deviate from the query.

The Internal Mechanism: Why Noise Causes Hallucinations

Research using mechanistic interpretability (ReDeEP, 2024, ICLR 2025) revealed the internal mechanism behind hallucinations in RAG systems:

How Hallucinations Actually Occur

Hallucinations occur when Knowledge FFNs (Feed-Forward Networks) in LLMs overemphasize parametric knowledge while Copying Heads fail to effectively retain or integrate external knowledge from retrieved content.

Translation: When faced with noisy context, the model falls back on what it already knows (parametric knowledge) rather than accurately extracting information from the retrieved content.

The research is unambiguous: noisy context doesn't just fail to help—it actively makes hallucinations more likely.

Web scraping systematically introduces the exact conditions research identifies as causing hallucinations:

  • Long contexts
  • Irrelevant content mixed with signal
  • Poor information positioning
  • High noise-to-signal ratios

The Multi-Source Dilemma

Research shows that complete information about a query is rarely found in a single source. Natural answers require aggregating information from multiple sources.

This creates a painful dilemma:

The Multi-Source Trade-off

FeatureSingle SourceMulti-Source (50+ publishers)
Answer QualityIncompleteComprehensive
CostsLowExponential
Legal RiskLowerMultiplied
Context NoiseManageableOverwhelming
MaintenanceSimpleUnsustainable

It's a catch-22: you need diversity for quality, but diversity multiplies cost and risk. And even with successful multi-source retrieval, multi-source synthesis remains challenging.

Web scraping forces an impossible trade-off between incomplete answers and unsustainable costs.

How to Provide Context to AI applications

Body Text Extraction: Imperfect Solutions to Scraping Problems

Some teams try to solve scraping's noise problem through Body Text Extraction (BTE)—algorithmically extracting article content from HTML bloat.

Tools like Boilerpipe library exist specifically to "detect and remove surplus clutter around main textual content" because web pages contain so much boilerplate and template content.

Problems with BTE:

BTE is a band-aid on the fundamental problem: trying to make unstructured, presentation-focused HTML work for data retrieval when structured formats are purpose-built for this use case.

Content Quality Standards

Trusted Publisher Content for AI Systems: Quality Standards Matter

How AI Agents Verify Content Authenticity (or Don't)

Most AI applications don't verify content authenticity—they scrape whatever they find and hope it's accurate.

This creates cascading quality problems:

1

Content Freshness

Scraped content might be outdated, but scrapers can't verify publication dates reliably (often buried in meta tags or relative time like '3 days ago')

2

Author Credibility

Expert bylines and institutional affiliations get stripped away during extraction, losing crucial authority signals

3

Editorial Standards

No way to distinguish between professional journalism and user-generated content or content farms

4

Fact-Checking Status

Corrections, retractions, and updates published after original article get missed

Content Quality Standards for AI Systems

What does "high-quality content" actually mean for AI applications? It's not just accuracy—it's structural compatibility with AI retrieval patterns.

Quality dimensions that affect AI performance:

  1. Factual accuracy: Incorrect information triggers hallucinations and user distrust
  2. Information density: More facts per token = more efficient context usage
  3. Structural clarity: Clear hierarchy (headline → summary → details) improves retrieval
  4. Source attribution: Links to primary sources enable verification and deeper research
  5. Temporal freshness: Outdated information can be worse than no information for time-sensitive queries
  6. Topical coherence: Single-topic content performs better than mixed-topic pages
  7. Semantic explicitness: Clear language outperforms jargon or assumed context
Scraped Content Systematically Underperforms

Scraped content fails on dimensions 2, 3, 4, 5, and 6 due to HTML bloat, presentation structure, boilerplate mixing, scraping snapshots, and ads/navigation mixing topics on every page.

Trusted Content Sources for Large Language Models

Research on content trustworthiness for AI identifies what users actually care about:

75%
Trust Requirement
Won't buy if they don't trust data use
67%
Data Protection
Prioritize hearing about data safety
51%
Switched Brands
Due to data privacy concerns
49%
Younger Users
Switched over data policies

The trust pyramid for AI content:

1

Tier 1: Highly Trusted

Major news organizations (NYT, WSJ, Reuters), academic institutions, government bodies, peer-reviewed journals. Premium rates in content marketplaces.

2

Tier 2: Moderately Trusted

Established digital publishers, vertical-specific sites, professional blogs, verified business sources. Standard rates.

3

Tier 3: Low Trust

User-generated content without oversight, content farms, SEO sites, social media posts, unverified blogs. Commodity rates or filtered out.

Web scraping treats all sources equally—you're as likely to retrieve a content farm as a credible publication. This creates quality variance that degrades average answer accuracy.

Content marketplaces with curation can filter by trust tier, allowing AI applications to optimize for quality vs. cost based on query importance.

The User Impact

The Quality Crisis: When Bloated Context Kills User Trust

How Context Bloat Affects User Experience

Users don't see your token count or your scraping infrastructure. What they experience is:

User-Facing Impact of Context Bloat

2-3x
Slower Responses
latency increase
20-45%
Less Accurate Answers
degradation
More
Vague Responses
hedging & uncertainty

Quality degradation from context bloat doesn't just annoy users—it destroys unit economics. When poor answer quality increases churn by just 5%, a 100K MAU app loses $250K in annual LTV, while acquisition costs to replace churned users run 5-7x higher than retention costs. Every percentage point of DAU/MAU decline compounds into hundreds of thousands in lost revenue, making context quality optimization one of the highest-ROI infrastructure investments for AI applications.

AI Content Access Without Web Scraping: The Alternatives

Structured Content Feeds and APIs

Publishers increasingly offer structured content access designed for programmatic consumption:

Publisher Content Access Options

FeatureFormatCharacteristics
RSS/Atom FeedsStructured XMLClean content but limited to recent articles, often truncated
Publisher APIsJSON/XMLRich metadata, clean text, real-time updates, built-in licensing
Content MarketplacesUnified APISingle integration, multi-publisher access, usage-based pricing

Challenges with traditional approaches:

  • Each publisher has different API structure and pricing
  • Most publishers don't offer APIs (especially smaller vertical publishers)
  • Negotiating individual deals doesn't scale beyond 10-20 publishers

Content Marketplaces for the Agentic Web

A new infrastructure category is emerging: content marketplaces purpose-built for AI agent access.

How content marketplaces work:

For AI applications (demand side):

  1. Single API integration accesses multiple publishers
  2. Query-based retrieval: request content by topic, not by scraping URLs
  3. Structured responses optimized for RAG ingestion
  4. Usage-based pricing: pay per query, not bulk licensing
  5. Automatic compliance: licensing built into marketplace terms

For publishers (supply side):

  1. List content with minimum pricing
  2. Marketplace bidding reveals fair market value
  3. Per-query compensation with usage verification
  4. Citation requirements ensure attribution
  5. Analytics showing exactly which content gets used

Content Marketplaces vs. Alternatives

FeatureAdvantageBenefit
vs. Scraping: LegalCopyright infringement riskProperly licensed with verifiable terms
vs. Scraping: Quality2.7-3.7x less denseStructured formats, editorial standards, freshness guarantees
vs. Scraping: Cost Efficiency$50K+ annual maintenancePay only for content that improves answers
vs. Traditional Licensing: PricingUpfront millions negotiatedMarket-driven competitive bidding
vs. Traditional Licensing: FlexibilityBulk deals lock you inUsage-based costs, access long-tail publishers

What AI Founders Should Do Differently

Stop optimizing scrapers. Start optimizing context.

The marginal gains from better prompt engineering or model fine-tuning pale compared to the step-function improvement from feeding your models clean, structured, relevant context instead of noisy HTML.

1

Measure Signal-to-Noise

What % of tokens in your retrieved context are actually relevant to the query? Track this metric rigorously.

2

Test Context Quality Impact

Run A/B test with same queries using scraped HTML vs. structured content. Measure accuracy, latency, hallucination rate.

3

Audit Worst Answers

What % trace back to noisy, confusing, or outdated context from scraping? This reveals your quality debt.

4

Calculate Quality-Adjusted Costs

Don't just measure token costs—measure cost per quality answer. Factor in churn from poor experiences.

5

Evaluate Alternatives

Content marketplaces, publisher APIs, structured feeds. Compare total cost of ownership including quality impact.

The AI companies that win won't have the most sophisticated models. They'll have the best context engineering—and that starts with eliminating web scraping's systematic quality degradation.

Want to Improve Your AI's quality?

Learn about content marketplaces purpose-built for the Agentic Web and how you can benefit from them.


Related Reading: For the complete analysis including cost breakdowns and legal risks, read The Hidden Cost of Web Scraping.

Deep Dive: Learn more about the real costs of web scraping for AI applications.

References

  1. Lost in the Middle: Liu, N. F., et al. (2024). Lost in the Middle: How Language Models Use Long Contexts. Transactions of the Association for Computational Linguistics. arXiv:2307.03172
  2. Context Length Impact: Context Length Alone Hurts LLM Performance Despite Perfect Retrieval (2025). arXiv:2510.05381
  3. RAG Performance: Long Context RAG Performance of Large Language Models (2024). arXiv:2411.03538
  4. Hallucination Rates: K2View. RAG hallucination - What is it and how to avoid it. Link
  5. Hallucination Types: A Survey on Hallucination in Large Language Models (2023). arXiv:2311.05232
  6. Mechanistic Interpretability: ReDeEP - Detecting Hallucination in Retrieval-Augmented Generation via Mechanistic Interpretability (2024). ICLR 2025. arXiv:2410.11414
  7. Multi-Source RAG: MSRS - Evaluating Multi-Source Retrieval-Augmented Generation. arXiv:2508.20867
  8. Consumer Trust: Cisco Newsroom. How safe is our data? Consumers want to know (2024). Link
  9. Trust Survey: PwC. 2024 Trust Survey - How to earn customer trust. Link