#4160 Upload File Types for LLMs: PDF or HTML; +PDF-to-XYZ Tools
#4160 Upload File Types for LLMs: PDF or HTML; +PDF-to-XYZ Tools #4160 When accepting files as input, do LLMs work better with PDF or HTML files? In 2026, the consensus among developers and AI researchers is that HTML (and its distilled cousin, Markdown) is significantly more effective for LLM input than PDF. While modern multimodal models (like Gemini 2.0 Flash or Claude 3.7) are remarkably good at "seeing" PDFs, HTML provides a native semantic structure that LLMs interpret with much higher reliability and lower token overhead. Why HTML Wins Semantic Hierarchy: HTML tags like <h1> , <table> , and <ul> provide explicit signals about data relationships. In contrast, a PDF is a "display format" where a header is just text with a larger font size. Token Efficiency: "Raw" PDFs often contain redundant layout data. Converting them to "clean" HTML or Markdown can reduce token counts by up to 90% without losing information, allow...