What is GPT-5.5 Instant?

GPT-5.5 Instant is cataloged under OpenAI / GPT with canonical ID openai/gpt-5.5-instant.

OPOpenAI/ GPT

GPT-5.5 Instant

openai/gpt-5.5-instant

Compact GPT model for low-latency assistance and high-volume workloads

Released

2026-05-05

Context window

400K

Max output

128K

Weights

Closed

Input

DocumentImageText

Output

Text

AttachmentsReasoningStructuredTemperatureTool call

Provider	Provider model ID	Protocol	Context	Max output	Input	Output	Capabilities	Notes	Pricing	Streaming
ZenMux	openai/gpt-5.5-instant	openai_chat	400K	128K			AttachmentsReasoningTool callStructuredTemperature	-	input $5/M · output $30/M cache read $0.5/M	Yes
OpenAI	gpt-5.5-instant	custom	400K	128K			-	-	-	Yes