ChatGPT Sources Mostly From Wikipedia While Google AI Overviews Sources Mostly From Reddit

06/11/25

TL;DR Summary of ChatGPT, Google AI Overviews, and Perplexity Source Citation Study

A recent analysis examined over 30 million citations from ChatGPT, Google AI Overviews, and Perplexity between August 2024 and June 2025. The study found that ChatGPT primarily cites Wikipedia, while both Google AI Overviews and Perplexity predominantly rely on Reddit as their main source. Google AI Overviews also frequently references YouTube and Quora, with Wikipedia featuring less prominently. These findings highlight distinct sourcing preferences among popular AI platforms.

Optimixed’s Overview: Key Insights into AI Content Source Preferences Across Leading Platforms

Study Analysis of Citation Patterns in AI Responses

A comprehensive study by Profound analyzed the source citations of three major AI platforms — ChatGPT, Google AI Overviews, and Perplexity — over nearly a year. The data reveals significant differences in how these systems source information:

  • ChatGPT relies heavily on Wikipedia, which accounts for 47.9% of its citations, making it the dominant information source.
  • Google AI Overviews prefer Reddit as the primary source at 21%, followed by YouTube and Quora, with Wikipedia only contributing 5.7%.
  • Perplexity shows a strong bias toward Reddit, with 46.7% of its citations coming from this platform.

Implications of Source Preferences

This divergence in citation sources suggests that each AI platform tailors its responses based on different content ecosystems, potentially affecting the style, depth, and reliability of answers. The prominence of Reddit in Google AI Overviews and Perplexity’s data highlights the growing influence of community-driven forums in AI knowledge bases, while ChatGPT’s reliance on Wikipedia emphasizes curated and encyclopedic content.

Additionally, the study noted variations when compared to a similar analysis by Ahrefs, indicating ongoing shifts and differences in AI sourcing strategies.

Source: Search Engine Roundtable by barry@rustybrick.com (Barry Schwartz). Read original article.