vs
9:0
overall capability wins (1 ties across 10 scored). GPT-5.5 leads overall.
- Reasoning6:0
- Coding1:0
- Arena1:0
- Pricing0:3
- Speed0:2
- Specs1:0
Verdict
GPT-5.5 leads coding (widest gap: +19.2 on SciCode); GPT-5.5 ranks higher on LMArena (+139 Elo); GPT-5.5 offers ~2.6x larger context (1.1M vs 400K).
- GPT-5.5 leads coding (widest gap: +19.2 on SciCode)
- GPT-5.5 ranks higher on LMArena (+139 Elo)
- GPT-5.5 offers ~2.6x larger context (1.1M vs 400K)
- GPT-5 Nano is ~81.8x cheaper on a blended token basis than GPT-5.5
Cost for 1M in + 250K out
Illustrative chat workload at primary-provider list prices.
- GPT-5.5
- $12.50
- GPT-5 Nano
- $0.15
GPT-5 Nano is about 83.3x 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
$5
$0.05
Output $/1M
$30
$0.40
Blended $/1M (3∶1)
$11.25
$0.14
Speed
tok/s
70
200
TTFT (s)
0.5
0.15
Reasoning
MMLU-Pro
—
—
GPQA Diamond
93.5
67.6
Humanity's Last Exam
45.8
9.5
AIME 2025
—
85.2
MATH-500
—
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
58.0
19.1
AA-LCR v1.1
84.3
45.0
CritPt
27.1
—
MMMU-Pro
79.9
61.0
IFBench
75.9
67.6
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
—
54.7
SWE-bench Pro
58.6
—
SWE-bench Multilingual
—
—
LiveCodeBench
—
—
Terminal-Bench 2.1
84.3
—
Aider Polyglot
—
48.4
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
55.8
36.6
CursorBench
58.4
—
SWE-Rebench
62.7
—
NL2Repo-Bench
—
—
DeepSWE
67.0
—
WebDev Arena
1,510
—
Terminal-Bench 4.0
—
—
CursorBench 4.0
—
—
FrontierCode v1.1 (Main)
—
—
Arena
LMArena Elo
1,476
1,338
| Metric | GPT-5.5 | 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 | $5 | $0.05 | B +$4.95 |
| Output $/1M | $30 | $0.40 | B +$29.60 |
| Blended $/1M (3∶1) | $11.25 | $0.14 | B +$11.11 |
| Speed | |||
| tok/s | 70 | 200 | B +130 |
| TTFT (s) | 0.5 | 0.15 | B +0.35 |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | 93.5 | 67.6 | A +25.9 pts |
| Humanity's Last Exam | 45.8 | 9.5 | A +36.3 pts |
| AIME 2025 | — | 85.2 | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | 58.0 | 19.1 | A +38.9 pts |
| AA-LCR v1.1 | 84.3 | 45.0 | A +39.3 pts |
| CritPt | 27.1 | — | — |
| MMMU-Pro | 79.9 | 61.0 | A +18.9 pts |
| IFBench | 75.9 | 67.6 | A +8.3 pts |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | — | 54.7 | — |
| SWE-bench Pro | 58.6 | — | — |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | — | — | — |
| Terminal-Bench 2.1 | 84.3 | — | — |
| Aider Polyglot | — | 48.4 | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | 55.8 | 36.6 | A +19.2 pts |
| CursorBench | 58.4 | — | — |
| SWE-Rebench | 62.7 | — | — |
| NL2Repo-Bench | — | — | — |
| DeepSWE | 67.0 | — | — |
| WebDev Arena | 1,510 | — | — |
| Terminal-Bench 4.0 | — | — | — |
| CursorBench 4.0 | — | — | — |
| FrontierCode v1.1 (Main) | — | — | — |
| Arena | |||
| LMArena Elo | 1,476 | 1,338 | A +139 Elo |
GPT-5.5
- Context
- 1.1M / 128K out
- Parameters
- —
- Price
- $5 / $30
- Speed
- 70 tok/s · 0.5s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Prior OpenAI flagship with strong coding and long context; still widely used alongside the newer 5.6 family.
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.