GPT OSS 120B
$0.725
estimated usage cost
1,000 requests × (1,000 uncached input × $0.35 + 500 output × $0.75) / 1,000,000 = $0.725
base rates; no context pricing tiers are published.
Text generation / OpenAI
GPT OSS 120B
GPT OSS 120B is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $0.35 per million input tokens. The advertised output rate is $0.75 per million output tokens.
api id: openai/gpt-oss-120b
how much does gpt oss 120b cost?
published base api rates · usd per 1m tokens
- input
- $0.35
- output
- $0.75
rates are published by the impossibl api. balance-purchase fees, taxes, tool charges, and workspace-specific pricing are separate.
specifications & capabilities
- creator
- OpenAI
- model type
- Text generation
- context window
- 128k tokens
- maximum output
- not published in the catalog
- input types
- text
- output types
- text
- tool calling
- not verified in the catalog
unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports.
estimate your usage
estimate your api cost
estimate text token usage for your workload. all amounts are in usd.
estimates use published impossibl api usage rates. configured billing adjustments, funding fees, taxes, and custom workspace rates are excluded and may change the final amount.
image and audio usage, cache creation, and additional tool charges are excluded. reasoning tokens count as billable output, even when they are not visible in the response.
compare more Text generation models
- GPT Chat Latest$5.00 input / 1m tokenscompare →
- GPT OSS 20B$0.075 input / 1m tokenscompare →
- GPT-3.5 Turbo$0.50 input / 1m tokenscompare →
- GPT-4 Turbo$10.00 input / 1m tokenscompare →
independent benchmarks
Results from Artificial Analysis. Each configuration is listed separately. These evaluations describe the tested model configuration; performance and costs can differ on Impossibl. Last checked 2026-09-11.
gpt-oss-120b (high)
| Benchmark | Score |
|---|---|
| Intelligence Index | 12.35 |
| Omniscience Index | -49.25 |
| GPQA | 78.18% |
| Humanity’s Last Exam | 19.60% |
| SciCode | 34.03% |
| CritPt | 1.14% |
| Terminal-Bench v2.1 | 26.22% |
| Terminal-Bench v4.0 | 0.00% |
| Terminal-Bench Hard | 23.48% |
| AA-LCR | 52.00% |
| Multilingual LCR | 1.11% |
| Harvey LAB | 13.89% |
| GDPval Elo | 744.74 |
| GDP.pdf All-pass | 4.00% |
| AutomationBench Partial | 0.20% |
| IFBench | 68.98% |
| Tau2 | 65.79% |
| Tau Banking | 12.78% |
| APEX-Agents | 3.10% |
| ITBench | 5.65% |
| LiveCodeBench | 87.83% |
| AIME 2025 | 93.44% |
| coding index (API) | 30.4 |
| agentic index (API) | 6.2 |
| intelligence index (API) | 12.3 |
Unmeasured scores are omitted. API values retain their source units.
view source ↗gpt-oss-120b (low)
| Benchmark | Score |
|---|---|
| Intelligence Index | 10.21 |
| Omniscience Index | -53.50 |
| GPQA | 67.17% |
| Humanity’s Last Exam | 5.89% |
| CritPt | 0.00% |
| Terminal-Bench v2.1 | 13.86% |
| Terminal-Bench Hard | 5.30% |
| AA-LCR | 46.00% |
| GDPval Elo | 364.46 |
| IFBench | 58.30% |
| Tau2 | 45.03% |
| Tau Banking | 2.89% |
| LiveCodeBench | 70.69% |
| AIME 2025 | 66.67% |
| coding index (API) | 21.2 |
| intelligence index (API) | 10.2 |
Unmeasured scores are omitted. API values retain their source units.
view source ↗frequently asked questions
What is GPT OSS 120B?
GPT OSS 120B is a text-generation model from OpenAI, available through the Impossibl API.
How much does GPT OSS 120B cost?
GPT OSS 120B costs $0.35 per million input tokens and $0.75 per million output tokens through the Impossibl API. All rates are in USD.
What is the context length of GPT OSS 120B?
GPT OSS 120B has a 128,000-token context window through the Impossibl API.
What inputs and outputs does GPT OSS 120B support?
GPT OSS 120B accepts text as input. GPT OSS 120B returns text.
How do I use GPT OSS 120B through an API?
GPT OSS 120B is available through the Impossibl API. Use openai/gpt-oss-120b as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.
When was GPT OSS 120B released?
OpenAI released GPT OSS 120B on August 5, 2025.
sources & coverage
this page describes GPT OSS 120B as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes.
model descriptions and release dates, where available, use the creator sources linked in the faq. api prices and limits use the impossibl catalog. benchmark results, where available, are credited to Artificial Analysis in the benchmarks section. report a correction →