gpt-oss-20b (free) is free for input tokens while GLM 4.5 Air costs $0.13 per 1M tokens.
API cost decision in 10 seconds
GLM 4.5 Air vs gpt-oss-20b (free)
Pick gpt-oss-20b (free) when budget is the priority.
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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 (free) when budget is the priority.
On the standard 1M input plus 500K output workload, gpt-oss-20b (free) is estimated at $0 vs $0.55 for GLM 4.5 Air, saving $0.55 (100% lower).
Cost-first pickgpt-oss-20b (free)
Context-first pickBoth models
Sample savings$0.55100%
10x traffic gap$5.55
The reported context window is tied, so cost and provider fit carry more weight. At 10x that traffic, the same price gap is about $5.55. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
gpt-oss-20b (free) stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | GLM 4.5 Air | gpt-oss-20b (free) |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | gpt-oss-20b (free) | $1.07 | $0 |
| Balanced workload | 1M input + 1M output | gpt-oss-20b (free) | $0.98 | $0 |
| Output-heavy chatbot | 1M input + 5M output | gpt-oss-20b (free) | $4.38 | $0 |
gpt-oss-20b (free) is free for output tokens while GLM 4.5 Air costs $0.85 per 1M tokens.
Both models report the same context window at 131.07K tokens.
gpt-oss-20b (free) is free for the standard workload while the other model is estimated at $0.55.
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 (free) has the lower input price; gpt-oss-20b (free) has the lower output price; both models report the same context window. For the 1M input plus 500K output sample, gpt-oss-20b (free) is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.55 for GLM 4.5 Air and $0 for gpt-oss-20b (free).
Choose GLM 4.5 Air when its provider, model quality, latency, or availability is more important than the numeric price/context winner.
Choose gpt-oss-20b (free) when you care most about lower input-token price, and lower output-token price.
- On the standard 1M input plus 500K output workload, gpt-oss-20b (free) is estimated at $0 vs $0.55 for GLM 4.5 Air, saving $0.55 (100% lower).
- gpt-oss-20b (free) is free for the standard workload while the other model is estimated at $0.55.
- gpt-oss-20b (free) is free for input tokens while GLM 4.5 Air costs $0.13 per 1M tokens.
- gpt-oss-20b (free) is free for output tokens while GLM 4.5 Air costs $0.85 per 1M tokens.
- Both models report the same context window at 131.07K tokens.
| Feature | GLM 4.5 Air (Z.ai) | gpt-oss-20b (free) (OpenAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.13 | $0 |
| Completion Price per 1M tokens | $0.85 | $0 |
| Sample Workload Cost 1M input + 500K output | $0.55 | $0 |
| Context Window | 131.07K | 131.07K |
| Release Date | ||
| Popularity | #37 | #72 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | gpt-oss-20b (free) | On the standard 1M input plus 500K output workload, gpt-oss-20b (free) is estimated at $0 vs $0.55 for GLM 4.5 Air, saving $0.55 (100% lower). |
| High-volume input processing | gpt-oss-20b (free) | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | gpt-oss-20b (free) | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | Tie | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- GLM 4.5 Air (free) can replace GLM 4.5 Air when lower sample workload cost matters most: $0.
- GLM 4 32B can replace GLM 4.5 Air when lower sample workload cost matters most: $0.15.
- GLM 4.7 Flash can replace GLM 4.5 Air when lower sample workload cost matters most: $0.26.
- Llama 4 Scout offers 10M context with $0.23 sample workload cost.
- Owl Alpha offers 1.05M context with $0 sample workload cost.
- DeepSeek V4 Flash offers 1.05M context with $0.2 sample workload cost.
- Gemini 2.5 Flash Lite offers 1.05M context with $0.3 sample workload cost.
- DeepSeek V4 Flash · DeepSeek · #1
- Hy3 preview · Tencent · #2
- Claude Opus 4.7 · Anthropic · #3
- Claude Sonnet 4.6 · Anthropic · #4
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