GPT-5.6 Sol vs GPT-6 Astra
Detailed pricing comparison and cost analysis.
Updated September 2026
Cost Simulator
| Feature | GPT-5.6 Sol | GPT-6 Astra |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Input Price (1M) | $4.00 | $10.00 |
| Output Price (1M) | $20.00 | $50.00 |
| Context Window | 1,000,000 | 1,050,000 |
Verdict
GPT-5.6 Sol costs $4.00 per 1M input tokens and $20.00 per 1M output tokens. GPT-6 Astra costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. GPT-5.6 Sol is 60% cheaper on input tokens than GPT-6 Astra. For output tokens, GPT-5.6 Sol is the more affordable option at $20.00/1M vs $50.00.
On context window, GPT-6 Astra supports 1,050,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.
When to choose GPT-5.6 Sol
- ✓ You need the lowest input token cost ($ 4.00/1M)
- ✓ Your workload is output-heavy — GPT-5.6 Sol generates text cheaper
- ✓ You are already integrated with OpenAI
When to choose GPT-6 Astra
- ✓ You need a larger context window (1,050,000 tokens)
- ✓ You are already integrated with OpenAI
Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.
Frequently Asked Questions
Is GPT-5.6 Sol cheaper than GPT-6 Astra? ▼
GPT-5.6 Sol is cheaper on input tokens at $4.00/1M vs $10.00/1M for GPT-6 Astra — a 60% saving.
What is the context window of GPT-5.6 Sol vs GPT-6 Astra? ▼
GPT-5.6 Sol has a 1,000,000-token context window. GPT-6 Astra has a 1,050,000-token context window. GPT-6 Astra supports the larger context, suitable for longer documents and agentic workflows.
Which model is better: GPT-5.6 Sol or GPT-6 Astra? ▼
The best choice depends on your use case. For cost efficiency on input tokens, GPT-5.6 Sol is the cheaper option. For maximum context length, GPT-6 Astra supports 1,050,000 tokens. Use the comparison table above to find the right fit for your workload.