name = "GPT-5.5 Pro"
description = "Highest-accuracy GPT-5.5 tier for slower, precision-heavy reasoning and coding"
family = "gpt-pro"
release_date = "2026-04-23"
last_updated = "2026-04-23"
attachment = true
reasoning = true
temperature = false
tool_call = true
structured_output = true
knowledge = "2025-12-01"
open_weights = false

[limit]
context = 1_050_000
input = 922_000
output = 128_000

[modalities]
input = ["text", "image", "pdf"]
output = ["text"]

[[benchmarks]]
name = "BrowseComp"
score = 90.1
metric = "accuracy"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "Humanity's Last Exam"
score = 43.1
metric = "accuracy"
variant = "no tools"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "Humanity's Last Exam"
score = 57.2
metric = "accuracy"
variant = "with tools"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "FrontierMath"
score = 52.4
metric = "accuracy"
dataset = "Tier 1-3"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "FrontierMath"
score = 39.6
metric = "accuracy"
dataset = "Tier 4"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "GDPval"
score = 82.3
metric = "wins or ties"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"

[[benchmarks]]
name = "GeneBench"
score = 33.2
metric = "accuracy"
source = "https://openai.com/index/introducing-gpt-5-5/"
date = "2026-04-23"