OpenAI

GPT-5.5 Pro

by OpenAItext+image+file->text2 endpoints
Neura Intelligence Index
78.6/ 100
Rank
#39
Confidence
low
Benchmarks
3(8% coverage)

Overview

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for...

Capabilities

Text generation
Image understanding
Tool use / Function calling
Structured output
Extended reasoning
Long context
File input
Deterministic seed

Modalities

Input
FileImageText
Output
Text

Technical Specifications

Context Window
1.1M tokens
Max Output
128K tokens
Knowledge Cutoff
2025-12-01
Tokenizer
GPT
Content Moderation
Enabled
Uptime (24h)
10000.0%
Country
🇺🇸US
Release Date
April 23, 20264mo

Supported Parameters

include_reasoningmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools

Benchmark Performance

math

BenchmarkScoreSource
FrontierMath
39.6
verified

reasoning

BenchmarkScoreSource
Humanity's Last Exam
57.2
verified

agent

BenchmarkScoreSource
BrowseComp
90.1
verified

Performance Over Time

Pricing

Per 1M tokens
Input$30.00
Output$180.00
Added
April 24, 2026
Last synced 9/18/2026