OpenAI
GPT-5.5
A very good delivery model that has been overtaken by cheaper Terra.
API pricing
USD per million tokens · OpenAI API Standard (≤272K input tokens)- Input
- $5
- Output
- $30
- Cached input
- $0.5
- Context window
- 1.05M
Try the visual runs
Open the generated scene to test it, or compare that prompt with another model.
Helm's Deep
Fortress siege scene testing scale, lighting, architecture, and cinematic atmosphere.
Hogwarts Broom Flight Simulator
Broom-flight scene testing depth, motion cues, castle scale, and fantasy mood.
Jabberwock
Dark fantasy encounter testing creature design, forest mood, and narrative staging.
Low Poly World
Stylized island build testing composition, color, and low-poly worldbuilding.
Office Life
Workplace vignette testing everyday scene logic, objects, and believable office detail.
Petri Dish
Microscopic ecosystem testing organic forms, scientific clarity, and cellular detail.
Universe Simulator
Cosmic system testing orbital structure, glowing bodies, scale, and simulation readability.
Vice City
Neon coastal city testing vehicles, architecture, atmosphere, and dense urban layout.
Yingzao Fashi Assembly
Timber assembly scene testing structure, joinery, construction order, and material clarity.
How GPT-5.5 compares
Three relevant peers, side by side.
- GPT-5.5 This model
- Claude Opus 4.8
- GPT-5.6 Luna
- GPT-5.6 Sol
6 benchmarks · 4 models
Official benchmark profile
Published scores outside our visual tests
SWE-bench Pro
58.6%Terminal-Bench 2.1
85.6%OSWorld 2.0
47.5%Full official benchmark table12 scores and peer comparisons
| Benchmark | Area | Score | Comparison |
|---|---|---|---|
| SWE-bench Pro | Coding | 58.6% | |
| Terminal-Bench 2.1 | Agentic coding | 85.6% | |
| OSWorld 2.0 | Computer use | 47.5% | |
| OSWorld-Verified | Computer use | 78.7% | |
| BrowseComp | Tool use | 84.4% | |
| BenchCAD | Computer-aided design | 44.4% | |
| BenchCAD with Python tool | Tool use | 59.4% | |
| GPQA Diamond | Academic reasoning | 93.6% | |
| FrontierMath Tier 1-3 v2 | Math | 85.3% | |
| FrontierMath Tier 4 v2 | Math | 72.5% | |
| GDPval | Professional work | 84.9% | |
| CyberGym | Cybersecurity | 81.8% |
Sources, pricing details and methodology
Verified model facts
Model specifications
- Status
- Current
- API model ID
gpt-5.5- Context
- 1.05M
- Max output
- 128K
- License
- Not publicly verified
- Access route
- Not publicly verified
- Modalities
- Not publicly verified
- Hardware
- Not publicly verified
- OpenAI API Standard (≤272K input tokens) · USD / 1M tokens
- $5 input · $0.5 cached input · $30 output
Above 272K input tokens, input is $10 and output is $45 per 1M tokens for the full session. Regional processing adds 10%.
Benchmark sources
GPT-5.5 rows combine OpenAI’s launch benchmarks with shared GPT-5.6 comparison rows where those make the score directly comparable to newer models.
Introducing GPT-5.5Evaluation settings
- OpenAI GPT-5.5 launch score; the GPT-5.6 shared comparison table reports 59.4% on its comparison run.
- Shared GPT-5.6 comparison table.
- OpenAI GPT-5.5 launch score.
- Shared GPT-5.6 comparison table and GPT-5.5 launch result.
- Vision2Code score without Python tool from the shared GPT-5.6 table.
- Vision2Code score with Python tool from the shared GPT-5.6 table.
- OpenAI science reasoning result and shared GPT-5.6 table.
Editorial verdict
Where this model fits
GPT-5.5 still writes clean code and fits OpenAI tooling well, but the August recording treats it as a relic of the previous generation: Terra is roughly half the API price in the current catalog and is now the team’s routine daily driver.
Best for
Watch out
Why it is ranked here
Evidence
Superbash editorial model ranking
Takeaway: GPT-5.5 is currently placed in Tier B.
The September 2026 editorial roster places GPT-5.5 at rank 13.
Open source →NEW AI Model Tier List for Vibe Coding!
Takeaway: Use GPT-5.5 in plan mode rather than as a long-horizon coding default.
The source video says it is strong and clean, but overthinks and spends too much context on extended builds.
Open source →Related guides