OpenAI Context Window (1.05M)

OpenAI's largest context window is 1.05M tokens, on GPT-5.4.

Data sourced from OpenRouter API and manual data collection | Last updated: Nov 3, 2026, 8:01 AM UTC

1M Context Window AI Models

Model Name	Context	Input	Output	Context Score
OpenAI: GPT-5.4	1.05M	922K	128K	71
OpenAI: GPT-5.4 Pro	1.05M	922K	128K	71
OpenAI: GPT-5.5	1.05M	922K	128K	71
OpenAI: GPT-5.5 Pro	1.05M	922K	128K	71
OpenAI: GPT-5.6 Luna	1.05M	922K	128K	71
OpenAI: GPT-5.6 Luna Pro	1.05M	922K	128K	71
OpenAI: GPT-5.6 Sol	1.05M	922K	128K	71
OpenAI: GPT-5.6 Sol Pro	1.05M	922K	128K	71
OpenAI: GPT-5.6 Terra	1.05M	922K	128K	71
OpenAI: GPT-5.6 Terra Pro	1.05M	922K	128K	71
OpenAI: GPT-6 Astra	1.05M	922K	128K	71
OpenAI: GPT-6 Astra Pro	1.05M	922K	128K	71
OpenAI: GPT-6 Luna	1.05M	922K	128K	71
OpenAI: GPT-6 Luna Pro	1.05M	922K	128K	71
OpenAI: GPT-6 Sol	1.05M	922K	128K	71
OpenAI: GPT-6 Sol Pro	1.05M	922K	128K	71
OpenAI: GPT-6.1 Sol	1.05M	922K	128K	71
OpenAI: GPT-6.1 Sol Pro	1.05M	922K	128K	71
OpenAI: GPT-6.1 Terra	1.05M	922K	128K	71
OpenAI: GPT-6.1 Terra Pro	1.05M	922K	128K	71
OpenAI: GPT-4.1	1.05M	1.01M	32.8K	71
OpenAI: GPT-4.1 Mini	1.05M	1.01M	32.8K	71
OpenAI: GPT-4.1 Nano	1.05M	105K	943K	71

Join the beta waitlist and get 50% off your first 3 months.

Model Name	Context	Input	Output	Context Score
OpenAI: GPT Chat Latest	400K	272K	128K	59
OpenAI: GPT-5	400K	272K	128K	59
OpenAI: GPT-5 Mini	400K	272K	128K	59
OpenAI: GPT-5 Nano	400K	272K	128K	59
OpenAI: GPT-5 Pro	400K	272K	128K	59
OpenAI: GPT-5.1	400K	272K	128K	59
OpenAI: GPT-5.1-Codex	400K	272K	128K	59
OpenAI: GPT-5.1-Codex-Max	400K	272K	128K	59
OpenAI: GPT-5.1-Codex-Mini	400K	272K	128K	59
OpenAI: GPT-5.2	400K	272K	128K	59
OpenAI: GPT-5.2 Pro	400K	272K	128K	59
OpenAI: GPT-5.2-Codex	400K	272K	128K	59
OpenAI: GPT-5.3-Codex	400K	272K	128K	59
OpenAI: GPT-5.4 Mini	400K	272K	128K	59
OpenAI: GPT-5.4 Nano	400K	272K	128K	59

	Model Name	Context	Input	Output	Context Score
	OpenAI: o3	200K	100K	100K	50
	OpenAI: o3 Pro	200K	100K	100K	50

Join the beta waitlist and get 50% off your first 3 months.

Model Name	Context	Input	Output	Context Score
OpenAI: gpt-oss-120b	131K	65.5K	65.5K	44
OpenAI: gpt-oss-20b	131K	13.1K	118K	44
OpenAI: gpt-oss-safeguard-20b	131K	65.5K	65.5K	44
OpenAI: GPT-4o	128K	112K	16.4K	44
OpenAI: GPT-4o-mini	128K	112K	16.4K	44
OpenAI: GPT-5.2 Chat	128K	96K	32K	44

	Model Name	Context	Input	Output	Context Score
	OpenAI: GPT-3.5 Turbo 16k	16.4K	12.3K	4.1K	18

	Model Name	Context	Input	Output	Context Score
	OpenAI: GPT-4	8.2K	4.1K	4.1K	9

	Model Name	Context	Input	Output	Context Score
	OpenAI: GPT-3.5 Turbo (older v0613)	4.1K	410	3.7K	0

Join the beta waitlist and get 50% off your first 3 months.

OpenAI's largest context window is 1.05M tokens, on GPT-5.4.