gpt-oss-120b Open vs GPT-5 Nano Paid
gpt-oss-120b vs GPT-5 Nano compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.
Prices & specs refreshed from live data · OpenSourceAI.tech
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
gpt-oss-120b vs GPT-5 Nano specs
| Spec | gpt-oss-120b | GPT-5 Nano |
|---|---|---|
| Maker | OpenAI | OpenAI |
| Type | Open-weight | Proprietary |
| Context window | 131K tokens | 400K tokens |
| Input price | $0.04/M · free self-host | $0.05/M |
| Output price | $0.17/M · free self-host | $0.4/M |
| Vision / multimodal | No | Yes |
| Tool / function calling | Yes | Yes |
| Self-hostable | Yes | No (API only) |
| License | Apache 2.0 | Proprietary |
Feature comparison
| Capability | gpt-oss-120b | GPT-5 Nano |
|---|---|---|
| Open weights (downloadable) | ✓ | ✗ |
| Self-hostable | ✓ | ✗ |
| Runs fully offline | ✓ | ✗ |
| Vision / multimodal | ✗ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✗ | ✗ |
Benchmarks: gpt-oss-120b vs GPT-5 Nano
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How gpt-oss-120b and GPT-5 Nano score
| Criterion | gpt-oss-120b | GPT-5 Nano |
|---|---|---|
| Cost-efficiency | 5.0 | 5.0 |
| Context window | 3.5 | 4.5 |
| Openness | 5.0 | 1.5 |
| Self-hosting | 5.0 | 1.0 |
| Multimodality | 3.5 | 5.0 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
What each model is
gpt-oss-120b Open
gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimize
GPT-5 Nano Paid
GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger...
Other models in these families
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Frequently asked questions
Is gpt-oss-120b as good as GPT-5 Nano?
gpt-oss-120b is open-weight and competitive on many tasks, but GPT-5 Nano may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.
Can I run gpt-oss-120b locally?
Yes. gpt-oss-120b has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-5 Nano is API-only and cannot be self-hosted.
How much cheaper is gpt-oss-120b?
gpt-oss-120b costs $0.17/M output vs $0.4/M for GPT-5 Nano — roughly 2x cheaper via API, and free if you self-host.
gpt-oss-120b vs GPT-5 Nano — which should I pick in 2026?
Choose gpt-oss-120b if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5 Nano if you want frontier capability through a managed API with zero infrastructure to run.
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