GPT-5 Nano is $29.95 cheaper per 1M input tokens (99.8% lower; 600x difference).
API cost decision in 10 seconds
GPT-5 Nano vs GPT-5.5 Pro
Pick GPT-5 Nano for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.
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Data confirmed:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick GPT-5 Nano for lower cost; pick GPT-5.5 Pro only if the larger context window matters more.
On the standard 1M input plus 500K output workload, GPT-5 Nano is estimated at $0.25 vs $120 for GPT-5.5 Pro, saving $119.75 (99.8% lower).
Cost-first pickGPT-5 Nano
Context-first pickGPT-5.5 Pro
Sample savings$119.7599.8%
10x traffic gap$1197.5
GPT-5.5 Pro has more context, but GPT-5 Nano saves $119.75 on the standard workload. At 10x that traffic, the same price gap is about $1197.5. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
GPT-5 Nano stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | GPT-5 Nano | GPT-5.5 Pro |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | GPT-5 Nano | $0.45 | $240 |
| Balanced workload | 1M input + 1M output | GPT-5 Nano | $0.45 | $210 |
| Output-heavy chatbot | 1M input + 5M output | GPT-5 Nano | $2.05 | $930 |
GPT-5 Nano is $179.6 cheaper per 1M output tokens (99.8% lower; 450x difference).
GPT-5.5 Pro has 650K more context (2.62x larger).
GPT-5 Nano is $119.75 cheaper on the standard workload (99.8% 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-5 Nano has the lower input price; GPT-5 Nano has the lower output price; GPT-5.5 Pro offers the larger context window. For the 1M input plus 500K output sample, GPT-5 Nano is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.25 for GPT-5 Nano and $120 for GPT-5.5 Pro.
Choose GPT-5 Nano when you care most about lower input-token price, and lower output-token price.
Choose GPT-5.5 Pro when you care most about larger context window.
- On the standard 1M input plus 500K output workload, GPT-5 Nano is estimated at $0.25 vs $120 for GPT-5.5 Pro, saving $119.75 (99.8% lower).
- GPT-5 Nano is $119.75 cheaper on the standard workload (99.8% lower).
- GPT-5 Nano is $29.95 cheaper per 1M input tokens (99.8% lower; 600x difference).
- GPT-5 Nano is $179.6 cheaper per 1M output tokens (99.8% lower; 450x difference).
- GPT-5.5 Pro has 650K more context (2.62x larger).
| Feature | GPT-5 Nano (OpenAI) | GPT-5.5 Pro (OpenAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.05 | $30 |
| Completion Price per 1M tokens | $0.4 | $180 |
| Sample Workload Cost 1M input + 500K output | $0.25 | $120 |
| Context Window | 400K | 1.05M |
| Release Date | ||
| Popularity | #68 | #122 |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | GPT-5 Nano | On the standard 1M input plus 500K output workload, GPT-5 Nano is estimated at $0.25 vs $120 for GPT-5.5 Pro, saving $119.75 (99.8% lower). |
| High-volume input processing | GPT-5 Nano | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | GPT-5 Nano | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-5.5 Pro | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- gpt-oss-120b (free) can replace GPT-5 Nano when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace GPT-5 Nano when lower sample workload cost matters most: $0.
- gpt-oss-20b can replace GPT-5 Nano when lower sample workload cost matters most: $0.1.
- gpt-oss-120b can replace GPT-5 Nano when lower sample workload cost matters most: $0.13.
- 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.
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Open OpenAI modelsGPT-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...
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