GPT-6.1 Sol vs GPT-6 Astra

Where it leads

• Lower input and output prices, $2 and $10 vs $10 and $50 per 1M tokens
• Higher Arena Text score, 1481 Elo vs 1476 Elo
• Cheaper cached input, $0.10 vs $1 per 1M tokens

Best for

• Agent loops that replay a large cached prefix
• A drop-in alternative to GPT-6 Sol at the same base cost

Watch out for

• The same 272,000-token long-context cliff applies, rebilling the full request at $4 input and $15 output
• Released a week after GPT-6 Sol at identical base pricing, so the two are easy to confuse on a rate card; the cached rate is the difference

Where it leads

• Higher Arena WebDev score, 1773 Elo vs 1751 Elo
• Higher GPQA Diamond score, 95.8% vs 95.4%
• Higher SimpleQA Verified score, 75.6% vs 73.9%

Best for

• Frontier reasoning and agentic evaluations where deep-context retrieval accuracy is the binding constraint
• Workloads that can be kept under the long-context threshold, where the effective rate stays at $10 / $50

Watch out for

• Long-context billing is a cliff, not a taper: a request over the long-context threshold is rebilled in full at $20 per million input and $75 per million output, so a prompt that crosses it costs roughly double
• GPT-6 Astra is the first publicly released model OpenAI classifies as crossing the Critical cybersecurity threshold under its own Preparedness Framework, which carries additional deployment safeguards
• Vendor-reported benchmark figures come from OpenAI’s own launch material and its own harness; they are not independently reproduced here