Open-weight models now process 29% of gateway tokens, up from 11% in April 2025.

GPT-4 launched and began its 52-week reign at the top of the ECI

Llama 4 was released approximately a year prior to Muse Spark and was generally considered a dead end within the AI community.

Llama 2 was used in an experiment that found AI-generated fact-checks are rated more helpful and less ideological than human ones.

Release of GPT-4, which established OpenAI's early dominance in the AI race.

Startup achieves 30% conversion lift by switching from GPT-4 to fine-tuned LLaMA 3 adapters for content optimization.

GPT-4 surpassed on ECI by GPT-4o and Claude 3.5 Sonnet, ending 18-month reign.

Llama 3.1 405B released, offering frontier-level performance as open-weight model.

Official public launch of GPT-4 by OpenAI

GPT-4 launched and began leading the ECI.