Solar Pro 3 is $1.1 cheaper per 1M input tokens (88% lower; 8.33x difference).
API cost decision in 10 seconds
Solar Pro 3 vs GPT-5.1
Pick Solar Pro 3 for lower cost; pick GPT-5.1 only if the larger context window matters more.
Pricing data updated:
Prices normalized to USD per 1M tokens
Sample workload: 1M input + 500K output
Budget verdict
Pick Solar Pro 3 for lower cost; pick GPT-5.1 only if the larger context window matters more.
On the standard 1M input plus 500K output workload, Solar Pro 3 is estimated at $0.45 vs $6.25 for GPT-5.1, saving $5.8 (92.8% lower).
Cost-first pickSolar Pro 3
Context-first pickGPT-5.1
Sample savings$5.892.8%
10x traffic gap$58
GPT-5.1 has more context, but Solar Pro 3 saves $5.8 on the standard workload. At 10x that traffic, the same price gap is about $58. Use the calculator below to replace the sample workload with your own token volume.
Cost sensitivity
Workload Sensitivity
Solar Pro 3 stays cheaper across input-heavy, balanced, and output-heavy sample workloads.
| Workload shape | Token mix | Better pick | Solar Pro 3 | GPT-5.1 |
|---|---|---|---|---|
| Input-heavy / RAG | 5M input + 500K output | Solar Pro 3 | $1.05 | $11.25 |
| Balanced workload | 1M input + 1M output | Solar Pro 3 | $0.75 | $11.25 |
| Output-heavy chatbot | 1M input + 5M output | Solar Pro 3 | $3.15 | $51.25 |
Solar Pro 3 is $9.4 cheaper per 1M output tokens (94% lower; 16.7x difference).
GPT-5.1 has 272K more context (3.12x larger).
Solar Pro 3 is $5.8 cheaper on the standard workload (92.8% 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
Solar Pro 3 has the lower input price; Solar Pro 3 has the lower output price; GPT-5.1 offers the larger context window. For the 1M input plus 500K output sample, Solar Pro 3 is cheaper for the standard workload.
For a 1M input token plus 500K output token workload, the estimated API cost is $0.45 for Solar Pro 3 and $6.25 for GPT-5.1.
Choose Solar Pro 3 when you care most about lower input-token price, and lower output-token price.
Choose GPT-5.1 when you care most about larger context window.
- On the standard 1M input plus 500K output workload, Solar Pro 3 is estimated at $0.45 vs $6.25 for GPT-5.1, saving $5.8 (92.8% lower).
- Solar Pro 3 is $5.8 cheaper on the standard workload (92.8% lower).
- Solar Pro 3 is $1.1 cheaper per 1M input tokens (88% lower; 8.33x difference).
- Solar Pro 3 is $9.4 cheaper per 1M output tokens (94% lower; 16.7x difference).
- GPT-5.1 has 272K more context (3.12x larger).
| Feature | Solar Pro 3 (Upstage) | GPT-5.1 (OpenAI) |
|---|---|---|
| Input Price prompt tokens per 1M | $0.15 | $1.25 |
| Completion Price per 1M tokens | $0.6 | $10 |
| Sample Workload Cost 1M input + 500K output | $0.45 | $6.25 |
| Context Window | 128K | 400K |
| Release Date |
Use-Case Decision Matrix
| Use case | Better pick | Why |
|---|---|---|
| Budget-constrained production | Solar Pro 3 | On the standard 1M input plus 500K output workload, Solar Pro 3 is estimated at $0.45 vs $6.25 for GPT-5.1, saving $5.8 (92.8% lower). |
| High-volume input processing | Solar Pro 3 | Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill. |
| Long responses and chatbots | Solar Pro 3 | Lower output-token price matters most when assistants generate many completion tokens. |
| RAG or long-document work | GPT-5.1 | A larger context window leaves more room for retrieved passages, conversation history, or source files. |
Related Alternatives
- gpt-oss-120b (free) can replace GPT-5.1 when lower sample workload cost matters most: $0.
- gpt-oss-20b (free) can replace GPT-5.1 when lower sample workload cost matters most: $0.
- gpt-oss-20b can replace GPT-5.1 when lower sample workload cost matters most: $0.1.
- gpt-oss-120b can replace GPT-5.1 when lower sample workload cost matters most: $0.13.
- Llama 4 Scout offers 10M context with $0.23 sample workload cost.
- Grok 4.20 Multi-Agent offers 2M context with $5 sample workload cost.
- Grok 4.20 offers 2M context with $2.5 sample workload cost.
- Owl Alpha offers 1.05M context with $0 sample workload cost.
- No popular competitor is currently available.
Cheaper alternatives
Review low-cost models sorted by a standard 1M input plus 500K output workload.
Open cheapest modelsLarger context alternatives
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