gpt-oss-20b is $1.22 cheaper per 1M input tokens (97.6% lower; 41.7x difference).
API cost decision in 10 seconds
gpt-oss-20b vs GPT-5 Chat
Pick gpt-oss-20b when budget and context both matter.
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Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick gpt-oss-20b when budget and context both matter.
On the standard 1M input plus 500K output workload, gpt-oss-20b is estimated at $0.1 vs $6.25 for GPT-5 Chat, saving $6.15 (98.4% lower).
Cost-first pickgpt-oss-20b
Context-first pickgpt-oss-20b
Sample savings$6.1598.4%
10x traffic gap$61.5
gpt-oss-20b is cheaper on the standard workload and also has the larger context window. At 10x that traffic, the same price gap is about $61.5. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
gpt-oss-20b stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | gpt-oss-20b | GPT-5 Chat |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | gpt-oss-20b | $0.22 | $11.25 |
| Balanced workload | 1M input + 1M output | gpt-oss-20b | $0.17 | $11.25 |
| Output-heavy chatbot | 1M input + 5M output | gpt-oss-20b | $0.73 | $51.25 |
gpt-oss-20b is $9.86 cheaper per 1M output tokens (98.6% lower; 71.4x difference).
gpt-oss-20b has 3.07K more context (1.02x larger).
gpt-oss-20b is $6.15 cheaper on the standard workload (98.4% lower).
Estimate your workload cost
Your Workload Cost
This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.
Quick Decision
gpt-oss-20b has the lower input price; gpt-oss-20b has the lower output price; gpt-oss-20b offers the larger context window. For the 1M input plus 500K output sample, gpt-oss-20b is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.1 for gpt-oss-20b and $6.25 for GPT-5 Chat.
Choose gpt-oss-20b when you care most about lower input-token price, lower output-token price, and larger context window.
Choose GPT-5 Chat when its provider, model quality, latency, or availability is more important than the numeric price/context winner.
- On the standard 1M input plus 500K output workload, gpt-oss-20b is estimated at $0.1 vs $6.25 for GPT-5 Chat, saving $6.15 (98.4% lower).
- gpt-oss-20b is $6.15 cheaper on the standard workload (98.4% lower).
- gpt-oss-20b is $1.22 cheaper per 1M input tokens (97.6% lower; 41.7x difference).
- gpt-oss-20b is $9.86 cheaper per 1M output tokens (98.6% lower; 71.4x difference).
- gpt-oss-20b has 3.07K more context (1.02x larger).
| Feature | gpt-oss-20b (OpenAI) | GPT-5 Chat (OpenAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.03 | $1.25 |
| Completion Price per 1M tokens | $0.14 | $10 |
| Sample Workload Cost 1M input + 500K output | $0.1 | $6.25 |
| Context Window | 131.07K | 128K |
| Release Date | ||
| Popularity | #67 | #111 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | gpt-oss-20b | On the standard 1M input plus 500K output workload, gpt-oss-20b is estimated at $0.1 vs $6.25 for GPT-5 Chat, saving $6.15 (98.4% lower). |
| High-volume input processing | gpt-oss-20b | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | gpt-oss-20b | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | gpt-oss-20b | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- gpt-oss-120b (free) can replace gpt-oss-20b when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace gpt-oss-20b when lower sample workload cost matters most: $0.
- gpt-oss-120b can replace GPT-5 Chat when lower sample workload cost matters most: $0.13.
- gpt-oss-safeguard-20b can replace GPT-5 Chat when lower sample workload cost matters most: $0.22.
- Llama 4 Scout offers 10M context with $0.23 sample workload cost.
- Grok 4.20 offers 2M context with $2.5 sample workload cost.
- Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
- Owl Alpha offers 1.05M context with $0 sample workload cost.
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Open OpenAI modelsgpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...
GPT-5 Chat is designed for advanced, natural, multimodal, and context-aware conversations for enterprise applications.