vs
0:13
overall capability wins (1 ties across 14 scored). GPT-5.5 leads overall.
- Reasoning0:7
- Coding0:3
- Arena0:1
- Tool use0:1
- Pricing3:0
- Speed2:0
- Specs0:1
Verdict
GPT-5.5 leads coding (widest gap: +49.1 on TermBench); GPT-5.5 ranks higher on LMArena (+41 Elo); GPT-5.5 offers ~2.6x larger context (1.1M vs 400K).
- GPT-5.5 leads coding (widest gap: +49.1 on TermBench)
- GPT-5.5 ranks higher on LMArena (+41 Elo)
- GPT-5.5 offers ~2.6x larger context (1.1M vs 400K)
- GPT-5 is ~3.3x 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
- $3.75
- GPT-5.5
- $12.50
GPT-5 is about 3.3x 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
Aug 7, 2025
Apr 23, 2026
Knowledge cutoff
2024-09
-
API / provider
OpenAI
OpenAI
Modalities
text, image → text
text, image → text
Specs
Context window
400K
1.1M
Max output
128K
128K
Parameters
—
—
Pricing
Input $/1M
$1.25
$5
Output $/1M
$10
$30
Blended $/1M (3∶1)
$3.44
$11.25
Speed
tok/s
90
70
TTFT (s)
0.4
0.5
Reasoning
MMLU-Pro
—
—
GPQA Diamond
85.4
93.5
Humanity's Last Exam
28.5
45.8
AIME 2025
94.6
—
MATH-500
—
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
40.3
58.0
AA-LCR v1.1
78.2
84.3
CritPt
5.7
27.1
MMMU-Pro
74.2
79.9
IFBench
73.1
75.9
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
74.9
—
SWE-bench Pro
41.8
58.6
SWE-bench Multilingual
—
—
LiveCodeBench
—
—
Terminal-Bench 2.1
35.2
84.3
Aider Polyglot
88.0
—
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
42.9
55.8
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
1,435
1,476
| Metric | GPT-5 | GPT-5.5 | Delta |
|---|---|---|---|
| Identity | |||
| Organization | OpenAI | OpenAI | — |
| Family | GPT-5.x | GPT-5.x | — |
| License | Proprietary | Proprietary | — |
| Open weights | No | No | — |
| Release | Aug 7, 2025 | Apr 23, 2026 | — |
| Knowledge cutoff | 2024-09 | - | — |
| API / provider | OpenAI | OpenAI | — |
| Modalities | text, image → text | text, image → text | — |
| Specs | |||
| Context window | 400K | 1.1M | B +650K |
| Max output | 128K | 128K | tie |
| Parameters | — | — | — |
| Pricing | |||
| Input $/1M | $1.25 | $5 | A +$3.75 |
| Output $/1M | $10 | $30 | A +$20 |
| Blended $/1M (3∶1) | $3.44 | $11.25 | A +$7.81 |
| Speed | |||
| tok/s | 90 | 70 | A +20 |
| TTFT (s) | 0.4 | 0.5 | A +0.10 |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | 85.4 | 93.5 | B +8.1 pts |
| Humanity's Last Exam | 28.5 | 45.8 | B +17.3 pts |
| AIME 2025 | 94.6 | — | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | 40.3 | 58.0 | B +17.7 pts |
| AA-LCR v1.1 | 78.2 | 84.3 | B +6.1 pts |
| CritPt | 5.7 | 27.1 | B +21.4 pts |
| MMMU-Pro | 74.2 | 79.9 | B +5.7 pts |
| IFBench | 73.1 | 75.9 | B +2.8 pts |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | 74.9 | — | — |
| SWE-bench Pro | 41.8 | 58.6 | B +16.8 pts |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | — | — | — |
| Terminal-Bench 2.1 | 35.2 | 84.3 | B +49.1 pts |
| Aider Polyglot | 88.0 | — | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | 42.9 | 55.8 | B +12.9 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 | 1,435 | 1,476 | B +41 Elo |
GPT-5
- Context
- 400K / 128K out
- Parameters
- —
- Price
- $1.25 / $10
- Speed
- 90 tok/s · 0.4s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Original GPT-5 GA release - still a strong price/performance option versus newer premium SKUs.
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.
Benchmark charts
Winner bars are emphasized. Per-benchmark deltas sit above each chart.