LLM Context Window Comparison 2026: GPT-4o vs Claude vs Gemini
Context windows have grown 2,500x in three years — from GPT-3’s 4K tokens in 2023 to Qwen Long’s 10M tokens in 2026. That growth is real, but advertised token counts and actual usable context are very different things. If you’re choosing a model for long-document analysis, agentic workflows, or codebase Q&A, the headline number will mislead you. This guide cuts through the marketing to compare GPT-4.1, Claude Opus 4.6, and Gemini 2.5 Pro on what actually matters: real retrieval performance across context lengths, cost at scale, and hidden pricing traps you’ll only discover on your first big invoice. ...