vs
1:0
overall capability wins (2 ties across 3 scored). GPT-5.4 Pro leads overall.
- Reasoning1:0
- Pricing0:3
- Speed0:2
Verdict
GPT-5.4 Pro edges reasoning & knowledge; GPT-5.5 is ~6.0x cheaper on a blended token basis than GPT-5.4 Pro.
- GPT-5.4 Pro edges reasoning & knowledge
- GPT-5.5 is ~6.0x cheaper on a blended token basis than GPT-5.4 Pro
Cost for 1M in + 250K out
Illustrative chat workload at primary-provider list prices.
- GPT-5.4 Pro
- $75
- GPT-5.5
- $12.50
GPT-5.5 is about 6.0x 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
Mar 5, 2026
Apr 23, 2026
Knowledge cutoff
-
-
API / provider
OpenAI
OpenAI
Modalities
text, image → text
text, image → text
Specs
Context window
1.1M
1.1M
Max output
128K
128K
Parameters
—
—
Pricing
Input $/1M
$30
$5
Output $/1M
$180
$30
Blended $/1M (3∶1)
$67.50
$11.25
Speed
tok/s
55
70
TTFT (s)
0.7
0.5
Reasoning
MMLU-Pro
—
—
GPQA Diamond
—
93.5
Humanity's Last Exam
—
45.8
AIME 2025
—
—
MATH-500
—
—
Humanity's Last Exam (with tools)
—
—
AA-Omniscience Accuracy
—
58.0
AA-LCR v1.1
—
84.3
CritPt
30.0
27.1
MMMU-Pro
—
79.9
IFBench
—
75.9
Chartography
—
—
Chartography (With Tools)
—
—
Coding
SWE-bench Verified
—
—
SWE-bench Pro
—
58.6
SWE-bench Multilingual
—
—
LiveCodeBench
—
—
Terminal-Bench 2.1
—
84.3
Aider Polyglot
—
—
Terminal-Bench 3
—
—
BigCodeBench
—
—
SciCode
—
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
—
1,476
| Metric | GPT-5.4 Pro | GPT-5.5 | Delta |
|---|---|---|---|
| Identity | |||
| Organization | OpenAI | OpenAI | — |
| Family | GPT-5.x | GPT-5.x | — |
| License | Proprietary | Proprietary | — |
| Open weights | No | No | — |
| Release | Mar 5, 2026 | Apr 23, 2026 | — |
| Knowledge cutoff | - | - | — |
| API / provider | OpenAI | OpenAI | — |
| Modalities | text, image → text | text, image → text | — |
| Specs | |||
| Context window | 1.1M | 1.1M | tie |
| Max output | 128K | 128K | tie |
| Parameters | — | — | — |
| Pricing | |||
| Input $/1M | $30 | $5 | B +$25 |
| Output $/1M | $180 | $30 | B +$150 |
| Blended $/1M (3∶1) | $67.50 | $11.25 | B +$56.25 |
| Speed | |||
| tok/s | 55 | 70 | B +15 |
| TTFT (s) | 0.7 | 0.5 | B +0.20 |
| Reasoning | |||
| MMLU-Pro | — | — | — |
| GPQA Diamond | — | 93.5 | — |
| Humanity's Last Exam | — | 45.8 | — |
| AIME 2025 | — | — | — |
| MATH-500 | — | — | — |
| Humanity's Last Exam (with tools) | — | — | — |
| AA-Omniscience Accuracy | — | 58.0 | — |
| AA-LCR v1.1 | — | 84.3 | — |
| CritPt | 30.0 | 27.1 | A +2.9 pts |
| MMMU-Pro | — | 79.9 | — |
| IFBench | — | 75.9 | — |
| Chartography | — | — | — |
| Chartography (With Tools) | — | — | — |
| Coding | |||
| SWE-bench Verified | — | — | — |
| SWE-bench Pro | — | 58.6 | — |
| SWE-bench Multilingual | — | — | — |
| LiveCodeBench | — | — | — |
| Terminal-Bench 2.1 | — | 84.3 | — |
| Aider Polyglot | — | — | — |
| Terminal-Bench 3 | — | — | — |
| BigCodeBench | — | — | — |
| SciCode | — | 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 | — | 1,476 | — |
GPT-5.4 Pro
- Context
- 1.1M / 128K out
- Parameters
- —
- Price
- $30 / $180
- Speed
- 55 tok/s · 0.7s TTFT
- Modalities
- text, image → text
- License
- Proprietary
Premium GPT-5.4 Pro compute tier at GPT-5.5 Pro list rates for hardest professional workloads.
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.