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GPT-5.5 Instant (June 2026)

OpenAIGPT

Description

GPT-5.5 Instant is OpenAI's latest Instant model and the default ChatGPT model released on May 5, 2026. It improves factuality, everyday reasoning, image understanding, STEM answers, concision, conversational tone, and personalization over GPT-5.3 Instant. In the API, it is exposed through the chat-latest alias, which points to the latest Instant model used in ChatGPT.

Release Date
2026-06-25
Parameters
Context Length
Modalities

Capability Radar

27
general
41
coding
82
reasoning
58
scienceest.
70
agents
85
multimodal

Science uses a reasoning proxy when dedicated science benchmarks are unavailable.

Rankings

Domain#RankScoreSource
Code Ranking121
62.0
AA
General Ranking218
47.0
AA
Science68
67.0
AA

Benchmark Scores (LLM Stats)

Biology

GPQA85.6%SR

General

MMMU-Pro76.0%SR

Healthcare

HealthBench Consensus94.7%SR
HealthBench51.4%SR
HealthBench Professional38.4%SR
HealthBench Hard22.9%SR

Math

AIME 202581.2%SR

Multimodal

OmniDocBench 1.587.5%SR
CharXiv-R81.6%SR

AA Evaluation Indices

Coding Index
39.4
Intelligence Index
28.9
Gpqa
0.8
Lcr
0.6
Scicode
0.5
Terminalbench V2 1
0.3
Hle
0.2
Tau Banking
0.1

LLM Stats Category Scores

Physics
90
Structured Output
90
Biology
90
Chemistry
90
Math
80
Multimodal
80
Reasoning
80
General
80
Vision
80
Healthcare
40

Pricing

Input Price$5 / 1M tokens
Output Price$30 / 1M tokens
Blended Price (3:1)$11.25 / 1M tokens

Speed

Tokens/sec0.0
Time to First Token0.00s
Time to Answer0.00s

Provider Price Ranking

Provider Price Ranking

4 providers

Cheapest: Vercel AI GatewayMost Expensive: ZenMux
ProviderInputOutput
1Vercel AI GatewayCheapest
$1.25
$10
2Poe
$1.6
$13
3OpenAIPRIMARY
$5
$30
4ZenMux
$5
$30

Compare pricing across different API providers for this model.

External Sources