DeepSeek V4.1 Flash vs GPT-6 Luna: pricing and benchmarks
GPT-6 Luna is 67% cheaper on input tokens ($0.10 vs $0.30 per 1M). GPT-6 Luna is 58% cheaper on output tokens ($0.50 vs $1.20 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $156.00 for DeepSeek V4.1 Flash, 65% less. Epoch AI has not published a capability index score for DeepSeek V4.1 Flash and GPT-6 Luna yet.
Prices verified September 26, 2026.
Which should you choose?
Epoch AI has not published a capability index score for DeepSeek V4.1 Flash and GPT-6 Luna yet.
GPT-6 Luna costs $0.20 per 1M tokens (3:1 input-to-output mix) vs $0.525 for DeepSeek V4.1 Flash, 62% less.
Pricing and specs
| DeepSeek V4.1 Flash | GPT-6 Luna | |
|---|---|---|
| Provider | DeepSeek | OpenAI |
| API model ID | deepseek-flash | gpt-6-luna |
| Input / 1M tokens | $0.30 | $0.10 |
| Cached input / 1M tokens | $0.006 | $0.01 |
| Output / 1M tokens | $1.20 | $0.50 |
| Long-context rates | — | $0.20 in / $0.75 out on long-context requests |
| Context window | 1M tokens | 1.05M tokens |
| Max output | 384K tokens | 128K tokens |
| Batch discount | — | 50% off |
Monthly cost for real workloads
| Workload | DeepSeek V4.1 Flash | GPT-6 Luna | Difference |
|---|---|---|---|
Support chatbot 100,000 replies a month, ~1,500 input tokens (system prompt + history) and ~400 output tokens each. | $93.00 | $35.00 | GPT-6 Luna 62% cheaper |
Document Q&A (RAG) 50,000 questions a month with ~8,000 tokens of retrieved context and ~600 output tokens each. | $156.00 | $55.00 | GPT-6 Luna 65% 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. | $61.68 | $24.80 | GPT-6 Luna 60% 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.
DeepSeek V4.1 Flash vs GPT-6 Luna cost calculator
- $55.00/mo$0.0011 / request
- DeepSeek V4.1 FlashDeepSeek$156.00/mo$0.0031 / 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.
DeepSeek V4.1 Flash pricing notes
DeepSeek’s low-cost model with thinking and non-thinking modes, tool calls and vision input.
- Prices shown are peak rates. Off-peak rates are half: peak hours are 01:00–04:00 and 06:00–10:00 UTC, Monday to Friday.
- Compatible with both OpenAI-format and Anthropic-format APIs.
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 DeepSeek V4.1 Flash cheaper than GPT-6 Luna?
- GPT-6 Luna is 67% cheaper on input tokens ($0.10 vs $0.30 per 1M). GPT-6 Luna is 58% cheaper on output tokens ($0.50 vs $1.20 per 1M). On our document Q&A workload (50,000 questions a month), GPT-6 Luna costs $55.00 a month versus $156.00 for DeepSeek V4.1 Flash, 65% less.
- Which is more capable, DeepSeek V4.1 Flash or GPT-6 Luna?
- Epoch AI has not published a capability index score for DeepSeek V4.1 Flash and GPT-6 Luna yet.
- How much does DeepSeek V4.1 Flash cost per 1M tokens?
- DeepSeek V4.1 Flash costs $0.30 per 1M input tokens and $1.20 per 1M output tokens, and $0.006 per 1M cached input tokens on DeepSeek’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, DeepSeek V4.1 Flash or GPT-6 Luna?
- GPT-6 Luna has the larger context window: 1.05M tokens versus 1M for DeepSeek V4.1 Flash.