Glimmer Index
Plus $4/mo

GPT-5.5 Pro

OpenAI · Released Apr 23, 2026 · Closed weights
Latest GPT-5.5 Pro

Highest-accuracy GPT-5.5 tier for slower, precision-heavy reasoning and coding

Strongest at
Reasoning
Top 9% of the past year's models · 3 of 5 benchmarks
Price per 1M tokens
$30 / $180
input / output · OpenAI
Context window
1.05M
tokens in · 128K out
Since the last one
49 days
after GPT-5.4 Pro
Open in the timeline

Capability profile

Scored against 91 models released in the past year. 50 is the average model; further out is better.

This modelGPT-5.4 ProMedian of the past year
5090Median of the past yearGPT-5.4 ProReasoning: 79 · Top 9%Math: 72 · Top 13%Science: 69 · Top 25%ReasoningMathScience
Reasoning79+1.8Top 9%
Math72+5.2Top 13%
Science69−5.9Top 25% · 1 test

No results yet: Coding, Writing, Reading & documents, Visual reasoning, Computer use

Where these scores come from

Each capability combines the published benchmarks listed here, rescaled so 50 is the reference average and 15 points is one standard deviation. A hollow dot rests on a single benchmark.

Price against capability

The shaded corner holds anything better and cheaper. Prices blend input and output 3 to 1.

6 models from the past year score higher on Reasoning for less: GPT-6.1 Terra, GPT-6 Astra, GPT-6.1 Sol and 3 more.

$0.1$0.3$1$3$10$3020406080100GPT-6.1 Terra: 99, $2 per 1MDeepSeek V4.1 Flash 1017: 74, $0.52 per 1MClaude Haiku 5.5: 64, $0.2 per 1MMistral Large 4: 53, $2.06 per 1MGemini 4 Argon: 85, $4 per 1MGPT-6.1 Sol: 87, $4 per 1MClaude Sonnet 5.5: 81, $4 per 1MGPT-6 Sol: 76, $4 per 1MGPT-6 Luna: 53, $0.2 per 1MClaude Opus 5.5: 84, $8 per 1MGrok 4.7: 60, $3 per 1MDeepSeek V4.1 Flash: 68, $0.21 per 1MGPT-6 Astra: 90, $20 per 1MMuse Spark 1.3: 60, $2 per 1MGemini 3.8 Flash: 75, $1.5 per 1MClaude Fable 5.1: 77, $20 per 1MGLM-5.3-Flash: 48, $0.24 per 1MDeepSeek V4 Flash Vision Exp: 54, $0.32 per 1MQwen3.8 27B: 49, $1.12 per 1MGLM-5.3: 60, $2.15 per 1MGemini 3.7 Flash: 73, $1.5 per 1MDeepSeek V4 Pro 0813: 66, $0.99 per 1MGrok 4.6: 66, $3 per 1MMuse Spark 1.2: 64, $2 per 1MQwen3.8 Max: 66, $3 per 1MDeepSeek V4 Flash 0731: 61, $0.15 per 1MClaude Opus 5: 76, $10 per 1MGemini 3.6 Flash: 61, $1.5 per 1MGemini 3.5 Flash Lite: 35, $0.85 per 1MKimi K3: 62, $6 per 1MQwen3.7 Flash: 42, $0.055 per 1MGPT-5.6 Terra: 66, $4.5 per 1MGPT-5.6 Sol: 76, $8 per 1MGPT-5.6 Luna: 57, $0.45 per 1MGrok 4.5: 63, $3 per 1MClaude Sonnet 5: 64, $4 per 1MGLM-5.2: 49, $2.15 per 1MKimi K2.7 Code: 51, $1.71 per 1MClaude Fable 5: 74, $20 per 1MQwen3.7 Plus: 44, $0.7 per 1MClaude Opus 4.8: 68, $10 per 1MQwen3.7 Max: 58, $3.75 per 1MGemini 3.5 Flash: 64, $3.38 per 1MDeepSeek V4 Pro: 48, $1.19 per 1MDeepSeek V4 Flash: 21, $0.18 per 1MGPT-5.5: 75, $11.2 per 1MQwen3.6 27B: 27, $1.35 per 1MKimi K2.6: 46, $1.71 per 1MGrok 4.3: 22, $1.56 per 1MGrok Build 0.1: 34, $1.25 per 1MClaude Opus 4.7: 63, $10 per 1MQwen3.6 35B-A3B: 49, $0.84 per 1MMuse Spark 1.1: 61, $2 per 1MGLM-5.1: 54, $2.15 per 1MQwen3.6 Plus: 33, $1.12 per 1MGPT-5.4 nano: 48, $0.46 per 1MGPT-5.4 mini: 40, $1.69 per 1MGPT-5.4: 68, $5.62 per 1MQwen3.5 Flash: 47, $0.18 per 1MQwen3.5 122B-A10B: 44, $1.1 per 1MGemini 3.1 Pro Preview: 68, $4.5 per 1MClaude Sonnet 4.6: 54, $6 per 1MQwen3.5 Plus: 43, $0.9 per 1MQwen3.5 397B-A17B: 45, $1.35 per 1MGLM-5: 47, $1.55 per 1MClaude Opus 4.6: 55, $10 per 1MKimi K2.5: 46, $1 per 1MGLM-4.7: 51, $1 per 1MGemini 3 Flash Preview: 58, $1.12 per 1MGPT-5.2 Pro: 69, $57.8 per 1MGPT-5.2 Codex: 37, $4.81 per 1MGPT-5.2: 59, $4.81 per 1MClaude Opus 4.5: 61, $10 per 1MGPT-5.1: 54, $3.44 per 1MGPT-5.4 Pro: 77, $67.5 per 1MGPT-5.5 Pro: 79, $67.5 per 1MGPT-5.5 ProPrice per 1M tokens →↑ Reasoning$0.1$1$1020406080100GPT-6.1 Terra: 99, $2 per 1MDeepSeek V4.1 Flash 1017: 74, $0.52 per 1MClaude Haiku 5.5: 64, $0.2 per 1MMistral Large 4: 53, $2.06 per 1MGemini 4 Argon: 85, $4 per 1MGPT-6.1 Sol: 87, $4 per 1MClaude Sonnet 5.5: 81, $4 per 1MGPT-6 Sol: 76, $4 per 1MGPT-6 Luna: 53, $0.2 per 1MClaude Opus 5.5: 84, $8 per 1MGrok 4.7: 60, $3 per 1MDeepSeek V4.1 Flash: 68, $0.21 per 1MGPT-6 Astra: 90, $20 per 1MMuse Spark 1.3: 60, $2 per 1MGemini 3.8 Flash: 75, $1.5 per 1MClaude Fable 5.1: 77, $20 per 1MGLM-5.3-Flash: 48, $0.24 per 1MDeepSeek V4 Flash Vision Exp: 54, $0.32 per 1MQwen3.8 27B: 49, $1.12 per 1MGLM-5.3: 60, $2.15 per 1MGemini 3.7 Flash: 73, $1.5 per 1MDeepSeek V4 Pro 0813: 66, $0.99 per 1MGrok 4.6: 66, $3 per 1MMuse Spark 1.2: 64, $2 per 1MQwen3.8 Max: 66, $3 per 1MDeepSeek V4 Flash 0731: 61, $0.15 per 1MClaude Opus 5: 76, $10 per 1MGemini 3.6 Flash: 61, $1.5 per 1MGemini 3.5 Flash Lite: 35, $0.85 per 1MKimi K3: 62, $6 per 1MQwen3.7 Flash: 42, $0.055 per 1MGPT-5.6 Terra: 66, $4.5 per 1MGPT-5.6 Sol: 76, $8 per 1MGPT-5.6 Luna: 57, $0.45 per 1MGrok 4.5: 63, $3 per 1MClaude Sonnet 5: 64, $4 per 1MGLM-5.2: 49, $2.15 per 1MKimi K2.7 Code: 51, $1.71 per 1MClaude Fable 5: 74, $20 per 1MQwen3.7 Plus: 44, $0.7 per 1MClaude Opus 4.8: 68, $10 per 1MQwen3.7 Max: 58, $3.75 per 1MGemini 3.5 Flash: 64, $3.38 per 1MDeepSeek V4 Pro: 48, $1.19 per 1MDeepSeek V4 Flash: 21, $0.18 per 1MGPT-5.5: 75, $11.2 per 1MQwen3.6 27B: 27, $1.35 per 1MKimi K2.6: 46, $1.71 per 1MGrok 4.3: 22, $1.56 per 1MGrok Build 0.1: 34, $1.25 per 1MClaude Opus 4.7: 63, $10 per 1MQwen3.6 35B-A3B: 49, $0.84 per 1MMuse Spark 1.1: 61, $2 per 1MGLM-5.1: 54, $2.15 per 1MQwen3.6 Plus: 33, $1.12 per 1MGPT-5.4 nano: 48, $0.46 per 1MGPT-5.4 mini: 40, $1.69 per 1MGPT-5.4: 68, $5.62 per 1MQwen3.5 Flash: 47, $0.18 per 1MQwen3.5 122B-A10B: 44, $1.1 per 1MGemini 3.1 Pro Preview: 68, $4.5 per 1MClaude Sonnet 4.6: 54, $6 per 1MQwen3.5 Plus: 43, $0.9 per 1MQwen3.5 397B-A17B: 45, $1.35 per 1MGLM-5: 47, $1.55 per 1MClaude Opus 4.6: 55, $10 per 1MKimi K2.5: 46, $1 per 1MGLM-4.7: 51, $1 per 1MGemini 3 Flash Preview: 58, $1.12 per 1MGPT-5.2 Pro: 69, $57.8 per 1MGPT-5.2 Codex: 37, $4.81 per 1MGPT-5.2: 59, $4.81 per 1MClaude Opus 4.5: 61, $10 per 1MGPT-5.1: 54, $3.44 per 1MGPT-5.4 Pro: 77, $67.5 per 1MGPT-5.5 Pro: 79, $67.5 per 1MGPT-5.5 ProPrice per 1M tokens →↑ Reasoning

OpenAI $30 / $180 · OpenRouter $30 / $180

Since GPT-5.4 Pro

4 releases in the GPT-5.5 Pro line.

GPT-5 ProOct 6, 202566dGPT-5.2 ProDec 11, 202584dGPT-5.4 ProMar 5, 202649dGPT-5.5 ProApr 23, 2026
Released49 days later
Price in / out$30 / $180same price
Context1.05Msame
Reasoning79+1.8
Math72+5.2
Science69−5.9
ECI STANDING#10 of 270
SCORE162.91160.04–166.6 CI
FRONTIER LAGLaunched in the leadNothing released before it had scored higher.
SCORES LIKE THESE MODELSClaude Opus 5Anthropic · Jul 2026163.94GPT-6 SolOpenAI · Sep 2026163.73Claude Fable 5Anthropic · Jun 2026163.42GPT-5.6 SolOpenAI · Jul 2026162.79
Full Epoch Capabilities Index ranking ↗

Epoch benchmark boards

Best result on each board it has run. The tick marks the leader.

SimpleBench
77%#4 of 89
GPQA diamond
94%#14 of 234
OTIS Mock AIME 2024-2025
100%#13 of 216
Chess Puzzles
62%#8 of 93
DTBench
96%#17 of 179
FrontierMath-Tiers-1-3-v2-Private
88%#9 of 90
ARC-AGI
96%#11 of 107
ARC-AGI-2
85%#14 of 103
1 more boards
FrontierMath-Tier-4-v2-Private
78%#12 of 72

OpenAI's past year

24 release days in the past year, about one every 15 days. The next is expected around Nov 8, 2026. Forecasts ↗

NovDecJanFebMarAprMayJunJulAugSepOctNov

Specifications

RELEASE DATEApr 23, 2026
WEIGHTSClosed weights
CONTEXT WINDOW1.05M
MAX OUTPUT128K
REASONINGNot listed
TOOL CALLINGNot listed
INPUTStext, image/jpeg, image/png, image/gif, image/webp, application/pdf
OUTPUTStext

Models.dev record ↗

Specifications and prices from Models.dev; availability and limits may differ by provider. Benchmarks from Epoch AI (CC BY 4.0), LiveBench and the other sources named above.