GPT-OSS-20B
GPT-OSS-20B is OpenAI's open-source lightweight model with 20 billion parameters, offering 128K context and fast inference for high-volume applications.
API Pricing
Cheapest on OpenRouter — 42% below avg| Provider | Input / 1M | Output / 1M | Speed | TTFT | Updated |
|---|---|---|---|---|---|
| $0.030 | $0.140 | 208 t/s | 443ms | 4/14/2026 | |
| $0.035 | $0.150 | 208 t/s | 443ms | 4/14/2026 | |
| $0.050 | $0.200 | 208 t/s | 443ms | 4/14/2026 | |
| $0.070 | $0.300 | 208 t/s | 443ms | 4/14/2026 | |
| $0.075 | $0.300 | 208 t/s | 443ms | 4/14/2026 |
Prices updated daily. Last check: 4/14/2026
Model Details
General
- Creator
- OpenAI
- Family
- GPT-OSS
- Tier
- Lightweight
- Context Window
- 128K
- Knowledge Cutoff
- Jan 2025
- Modalities
- Text
Capabilities
- Tool Calling
- No
- Open Source
- Yes
- Subtypes
- Chat Completion
Strengths & Limitations
- Open-source model weights available for self-hosting and customization
- Fast inference speed at 222.5 tokens per second output rate
- 128K token context window supports long document processing
- Low time to first token at 389ms enables responsive applications
- January 2025 knowledge cutoff provides recent training data
- 20B parameter size balances capability with computational efficiency
- Text-focused architecture optimized for chat completion tasks
- No tool calling or function execution capabilities
- Text-only modality lacks image or multimodal input support
- Lightweight tier positioning means less capable than frontier models
- Smaller parameter count than larger models in competing families
- Self-hosting requires significant infrastructure and technical expertise
Key Features
About GPT-OSS-20B
Common Use Cases
GPT-OSS-20B is designed for organizations requiring high-volume text processing with model ownership and customization capabilities. Its lightweight architecture and fast inference make it suitable for customer service chatbots, content moderation, document summarization, and text classification tasks where response speed matters. The open-source nature enables fine-tuning for domain-specific applications, compliance requirements, or cost optimization through self-hosting. The 128K context window supports applications processing long documents, legal texts, or extended conversations while maintaining computational efficiency.
Frequently Asked Questions
How much does GPT-OSS-20B cost per million tokens?
GPT-OSS-20B pricing varies by provider and deployment method, with some providers offering hosted inference while others support self-hosting the open-source weights. Check the pricing table above for current rates across all available providers.
What is GPT-OSS-20B best used for?
GPT-OSS-20B excels at high-volume text processing applications like customer service automation, content moderation, document analysis, and text classification. Its open-source nature makes it ideal for organizations needing model customization, compliance requirements, or cost control through self-hosting.
Can I fine-tune or modify GPT-OSS-20B for my specific use case?
Yes, GPT-OSS-20B provides open-source model weights that can be fine-tuned and customized for specific domains or applications. This enables organizations to adapt the model for specialized tasks, compliance requirements, or performance optimization while maintaining full control over the deployment.