GPT-1 vs GPT-5 Pro

OpenAI vs OpenAI — benchmarks, pricing, and capabilities side by side.

•GPT-5 Pro has a larger context window (400K)

	GPT-1	GPT-5 Pro
Intelligence index	—	88.4
Developer	OpenAI	OpenAI
Type	LLM	LLM
Access	Open weights	API only
Context window	512 tokens	400,000 tokens
Input price	—	$15.00 / 1M
Output price	—	$120.00 / 1M
Speed	—	—
Released	June 11, 2018	October 6, 2025
Parameters	117M	—
Input modalities	Text	Text, Image
Output modalities	Text	Text

GPT-1 details GPT-5 Pro details