GPT-6.1 Sol vs GPT-6 Luna: pricing and benchmarks
GPT-6 Luna is 95% cheaper on input tokens ($0.10 vs $2.00 per 1M). GPT-6 Luna is 95% cheaper on output tokens ($0.50 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $1,100 for GPT-6.1 Sol, 95% less. Epoch AI has not published a capability index score for GPT-6.1 Sol and GPT-6 Luna yet.
Prices verified October 3, 2026.
Which should you choose?
Epoch AI has not published a capability index score for GPT-6.1 Sol and GPT-6 Luna yet.
GPT-6 Luna costs $0.20 per 1M tokens (3:1 input-to-output mix) vs $4.00 for GPT-6.1 Sol, 95% less.
Pricing and specs
| GPT-6.1 Sol | GPT-6 Luna | |
|---|---|---|
| Provider | OpenAI | OpenAI |
| API model ID | gpt-6.1-sol | gpt-6-luna |
| Input / 1M tokens | $2.00 | $0.10 |
| Cached input / 1M tokens | $0.10 | $0.01 |
| Output / 1M tokens | $10.00 | $0.50 |
| Long-context rates | $4.00 in / $15.00 out above 272K prompt tokens | $0.20 in / $0.75 out on long-context requests |
| Context window | 1.05M tokens | 1.05M tokens |
| Max output | 128K tokens | 128K tokens |
| Batch discount | 50% off | 50% off |
Monthly cost for real workloads
| Workload | GPT-6.1 Sol | GPT-6 Luna | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $700.00 | $35.00 | GPT-6 Luna 95% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $1,100 | $55.00 | GPT-6 Luna 95% cheaper |
Coding agent 10,000 agent steps a month, ~40,000 input tokens each (70% read from the prompt cache) and ~2,000 output tokens. | $468.00 | $24.80 | GPT-6 Luna 95% cheaper |
Estimates use standard list prices and ignore cache-write surcharges. Different tokenizers can count the same text differently, so test with your own prompts.
GPT-6.1 Sol vs GPT-6 Luna cost calculator
- $55.00/mo$0.0011 / request
- GPT-6.1 SolOpenAI$1,100/mo$0.02 / request
Standard-tier list prices. Long-context rates apply automatically where the provider publishes a threshold. Excludes cache-write surcharges, taxes, batch and volume discounts.
GPT-6.1 Sol pricing notes
OpenAI’s update to GPT-6 Sol, with near-Astra performance for complex work at a lower cost.
- Cached input costs $0.10 per 1M tokens, half of GPT-6 Sol’s $0.20.
- Cache writes are billed at $2.50 per 1M tokens.
- Prompts over 272K input tokens use the long-context rates.
- Fast mode costs 2x the standard rate; Flex costs half.
GPT-6 Luna pricing notes
OpenAI’s most efficient GPT-6 model, for focused, high-volume tasks.
- Cache writes are billed at $0.125 per 1M tokens.
- Fast mode costs 2x the standard rate; Flex costs half.
- Regional (data residency) endpoints add a 10% uplift, and EU data residency is available only with standard processing.
Frequently asked questions
- Is GPT-6.1 Sol cheaper than GPT-6 Luna?
- GPT-6 Luna is 95% cheaper on input tokens ($0.10 vs $2.00 per 1M). GPT-6 Luna is 95% cheaper on output tokens ($0.50 vs $10.00 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $1,100 for GPT-6.1 Sol, 95% less.
- Which is more capable, GPT-6.1 Sol or GPT-6 Luna?
- Epoch AI has not published a capability index score for GPT-6.1 Sol and GPT-6 Luna yet.
- How much does GPT-6.1 Sol cost per 1M tokens?
- GPT-6.1 Sol costs $2.00 per 1M input tokens and $10.00 per 1M output tokens, and $0.10 per 1M cached input tokens on OpenAI’s standard tier.
- How much does GPT-6 Luna cost per 1M tokens?
- GPT-6 Luna costs $0.10 per 1M input tokens and $0.50 per 1M output tokens, and $0.01 per 1M cached input tokens on OpenAI’s standard tier.
- Which has the larger context window, GPT-6.1 Sol or GPT-6 Luna?
- Both offer a 1.05M-token context window.