vs
0:3
overall capability wins (1 ties across 4 scored). GPT-5.5 Pro leads overall.
- Reasoning0:2
- Pricing3:0
- Speed2:0
- Specs0:1
Verdict
GPT-5.5 Pro edges reasoning & knowledge; GPT-5.5 Pro offers ~2.6x larger context (1.1M vs 400K); GPT-5 is ~19.6x 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 is ~19.6x 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
- $3.75
- GPT-5.5 Pro
- $75
GPT-5 is about 20.0x 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
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
$30
Output $/1M
$10
$180
Blended $/1M (3∶1)
$3.44
$67.50
Speed
tok/s
90
68
TTFT (s)
0.4
0.8
Reasoning
MMLU-Pro
—
—
GPQA Diamond
85.4
—
Humanity's Last Exam
28.5
43.1
AIME 2025
94.6
—
MATH-500
—
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
40.3
—
AA-LCR v1.1
78.2
—
CritPt
5.7
30.6
MMMU-Pro
74.2
—
IFBench
73.1
—
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
74.9
—
SWE-bench Pro
41.8
—
SWE-bench Multilingual
—
—
LiveCodeBench
—
—
Terminal-Bench 2.1
35.2
—
Aider Polyglot
88.0
—
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
42.9
—
CursorBench
—
—
SWE-Rebench
—
—
NL2Repo-Bench
—
—
DeepSWE
—
—
WebDev Arena
—
—
Terminal-Bench 4.0
—
—
CursorBench 4.0
—
—
FrontierCode v1.1 (Main)
—
—
Arena
LMArena Elo
1,435
—
| Metric | GPT-5 | GPT-5.5 Pro | 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 | $30 | A +$28.75 |
| Output $/1M | $10 | $180 | A +$170 |
| Blended $/1M (3∶1) | $3.44 | $67.50 | A +$64.06 |
| Speed | |||
| tok/s | 90 | 68 | A +22 |
| TTFT (s) | 0.4 | 0.8 | A +0.40 |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | 85.4 | — | — |
| Humanity's Last Exam | 28.5 | 43.1 | B +14.6 pts |
| AIME 2025 | 94.6 | — | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | 40.3 | — | — |
| AA-LCR v1.1 | 78.2 | — | — |
| CritPt | 5.7 | 30.6 | B +24.9 pts |
| MMMU-Pro | 74.2 | — | — |
| IFBench | 73.1 | — | — |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | 74.9 | — | — |
| SWE-bench Pro | 41.8 | — | — |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | — | — | — |
| Terminal-Bench 2.1 | 35.2 | — | — |
| Aider Polyglot | 88.0 | — | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | 42.9 | — | — |
| CursorBench | — | — | — |
| SWE-Rebench | — | — | — |
| NL2Repo-Bench | — | — | — |
| DeepSWE | — | — | — |
| WebDev Arena | — | — | — |
| Terminal-Bench 4.0 | — | — | — |
| CursorBench 4.0 | — | — | — |
| FrontierCode v1.1 (Main) | — | — | — |
| Arena | |||
| LMArena Elo | 1,435 | — | — |
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 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.
Benchmark charts
Winner bars are emphasized. Per-benchmark deltas sit above each chart.