Google Deploys ALF: A Next-Gen AI for Fraud Detection in Google Ads
On December 31, 2025, Google published a research paper introducing ALF (Advertiser Large Foundation Model), a new AI system for detecting fraud in Google Ads. According to the paper, ALF is already deployed and has shown substantial improvements over previous systems, achieving:
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+40 percentage points increase in detection recall for key policies
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99.8% precision on certain policy violations
What is ALF?
ALF is a multimodal large foundation model designed to understand advertisers holistically. It analyzes:
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Structured data: account age, billing details, historical performance
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Unstructured creative assets: text, images, and videos
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Landing page content
The model works by comparing multiple signals together, rather than evaluating them in isolation. For example:
“An advertiser might have a newly created account, ads featuring a well-known brand, and a single declined payment. Individually, these may seem innocuous, but together they strongly suggest fraudulent intent.”
Key Challenges ALF Overcomes
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Heterogeneous & High-Dimensional Data
- Advertiser data comes in many formats (structured and unstructured) and contains thousands of features, which previous models struggled to process effectively.
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Unbounded Sets of Creative Assets
- Malicious content can be hidden among thousands of innocent assets. Previous systems could not reliably detect these outliers.
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Real-World Reliability & Trustworthiness
- ALF generates trustworthy confidence scores to minimize false positives, protecting legitimate advertisers while maintaining detection accuracy.
Privacy and Safety
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ALF analyzes sensitive account signals, but all personally identifiable information (PII) is stripped before processing.
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The model focuses on behavioral patterns, not individual identities.
The “Secret Sauce”: Inter-Sample Attention
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ALF doesn’t evaluate advertisers in isolation.
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Using large advertiser batches, it compares behaviors across the ecosystem.
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This contextual comparison helps identify suspicious outliers more accurately than previous systems.
Performance Highlights
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ALF outperforms production baselines and public benchmarks.
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Gains are achieved across multiple evaluation metrics in real-world production conditions, not just offline testing.
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While ALF has higher latency than simpler models, it remains well within acceptable production limits and scales to handle millions of requests daily.
Impact on Google Ads Safety
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ALF is currently deployed for fraud detection and policy enforcement in Google Ads.
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Future potential applications include:
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Temporal modeling for evolving fraudulent patterns
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Audience modeling
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Creative optimization
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Why It Matters
ALF represents a major leap in AI-driven advertiser monitoring:
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Combines multimodal content understanding with structured account data
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Delivers high precision and recall, improving ad ecosystem trustworthiness
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Balances accuracy with scalable deployment at production scale
Original Research Paper:
ALF: Advertiser Large Foundation Model for Multi-Modal Advertiser Understanding
