vs
2:0
overall capability wins (1 ties across 3 scored). GPT-5.5 Pro leads overall.
- Reasoning1:0
- Pricing0:3
- Speed0:2
- Specs1:0
Verdict
GPT-5.5 Pro edges reasoning & knowledge; GPT-5.5 Pro offers ~2.6x larger context (1.1M vs 400K); GPT-5 Nano is ~490.9x cheaper on a blended token basis than GPT-5.5 Pro.
- GPT-5.5 Pro edges reasoning & knowledge
- GPT-5.5 Pro offers ~2.6x larger context (1.1M vs 400K)
- GPT-5 Nano is ~490.9x cheaper on a blended token basis than GPT-5.5 Pro
Cost for 1M in + 250K out
Illustrative chat workload at primary-provider list prices.
- GPT-5.5 Pro
- $75
- GPT-5 Nano
- $0.15
GPT-5 Nano is about 500.0x cheaper on this workload.
Price per 1M tokens
Full comparison
Organization
OpenAI
OpenAI
Family
GPT-5.x
GPT-5.x
License
Proprietary
Proprietary
Open weights
No
No
Release
Apr 23, 2026
Aug 7, 2025
Knowledge cutoff
-
-
API / provider
OpenAI
OpenAI
Modalities
text, image → text
text, image → text
Specs
Context window
1.1M
400K
Max output
128K
128K
Parameters
—
—
Pricing
Input $/1M
$30
$0.05
Output $/1M
$180
$0.40
Blended $/1M (3∶1)
$67.50
$0.14
Speed
tok/s
68
200
TTFT (s)
0.8
0.15
Reasoning
MMLU-Pro
—
—
GPQA Diamond
—
67.6
Humanity's Last Exam
43.1
9.5
AIME 2025
—
85.2
MATH-500
—
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
—
19.1
AA-LCR v1.1
—
45.0
CritPt
30.6
—
MMMU-Pro
—
61.0
IFBench
—
67.6
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
—
54.7
SWE-bench Pro
—
—
SWE-bench Multilingual
—
—
LiveCodeBench
—
—
Terminal-Bench 2.1
—
—
Aider Polyglot
—
48.4
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
—
36.6
CursorBench
—
—
SWE-Rebench
—
—
NL2Repo-Bench
—
—
DeepSWE
—
—
WebDev Arena
—
—
Terminal-Bench 4.0
—
—
CursorBench 4.0
—
—
FrontierCode v1.1 (Main)
—
—
Arena
LMArena Elo
—
1,338
| Metric | GPT-5.5 Pro | GPT-5 Nano | Delta |
|---|---|---|---|
| Identity | |||
| Organization | OpenAI | OpenAI | — |
| Family | GPT-5.x | GPT-5.x | — |
| License | Proprietary | Proprietary | — |
| Open weights | No | No | — |
| Release | Apr 23, 2026 | Aug 7, 2025 | — |
| Knowledge cutoff | - | - | — |
| API / provider | OpenAI | OpenAI | — |
| Modalities | text, image → text | text, image → text | — |
| Specs | |||
| Context window | 1.1M | 400K | A +650K |
| Max output | 128K | 128K | tie |
| Parameters | — | — | — |
| Pricing | |||
| Input $/1M | $30 | $0.05 | B +$29.95 |
| Output $/1M | $180 | $0.40 | B +$179.60 |
| Blended $/1M (3∶1) | $67.50 | $0.14 | B +$67.36 |
| Speed | |||
| tok/s | 68 | 200 | B +132 |
| TTFT (s) | 0.8 | 0.15 | B +0.65 |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | — | 67.6 | — |
| Humanity's Last Exam | 43.1 | 9.5 | A +33.6 pts |
| AIME 2025 | — | 85.2 | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | — | 19.1 | — |
| AA-LCR v1.1 | — | 45.0 | — |
| CritPt | 30.6 | — | — |
| MMMU-Pro | — | 61.0 | — |
| IFBench | — | 67.6 | — |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | — | 54.7 | — |
| SWE-bench Pro | — | — | — |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | — | — | — |
| Terminal-Bench 2.1 | — | — | — |
| Aider Polyglot | — | 48.4 | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | — | 36.6 | — |
| CursorBench | — | — | — |
| SWE-Rebench | — | — | — |
| NL2Repo-Bench | — | — | — |
| DeepSWE | — | — | — |
| WebDev Arena | — | — | — |
| Terminal-Bench 4.0 | — | — | — |
| CursorBench 4.0 | — | — | — |
| FrontierCode v1.1 (Main) | — | — | — |
| Arena | |||
| LMArena Elo | — | 1,338 | — |
GPT-5.5 Pro
- Context
- 1.1M / 128K out
- Parameters
- —
- Price
- $30 / $180
- Speed
- 68 tok/s · 0.8s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Premium compute tier for GPT-5.5 with elevated reasoning budgets; priced for highest-complexity workloads.
GPT-5 Nano
- Context
- 400K / 128K out
- Parameters
- —
- Price
- $0.05 / $0.40
- Speed
- 200 tok/s · 0.15s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Ultra-cheap OpenAI tier for classification, extraction, and simple assistants.
Benchmark charts
Winner bars are emphasized. Per-benchmark deltas sit above each chart.