GPT-5.6 Luna vs DeepSeek V4.1 Flash pricing
Side-by-side LLM API pricing.DeepSeek V4.1 Flash is cheaper on input ($0.15 vs $0.20 /1M), and DeepSeek V4.1 Flash is cheaper on output ($0.60 vs $1.20 /1M). On a blended average, DeepSeek V4.1 Flash is lower — but which wins for you depends on your input/output mix, so check the example workloads below or run the calculator.
| Attribute | GPT-5.6 Luna | DeepSeek V4.1 Flash |
|---|---|---|
| Provider | OpenAI | DeepSeek |
| Tier | Budget | Budget |
| Status | GA | GA |
| Context window | 1.05M | 1M |
| Input /1M | $0.20 | $0.15 |
| Output /1M | $1.20 | $0.60 |
| Cached input /1M | $0.02 | $0.003 |
| Batch input /1M | $0.10 | — |
| Batch output /1M | $0.60 | — |
| Blended (avg in+out) | $0.70 | $0.375 |
| 1M in + 1M out | $1.40 | $0.7500 |
| 1M in (90% cached) + 100K out | $0.1580 | $0.0777 |
List prices, USD, directional. Rates are provider list prices per 1M tokens and are meant for comparison, not billing. Batch rates shown as 50% off are derived where a provider offers batch but does not publish a separate figure. Preview, promo, intro, peak/off-peak, long-context, and third-party-host prices are labeled where they apply. Token counts vary by tokenizer, so per-token price is not always a like-for-like cost. Always confirm with the provider before relying on a number. Prices as of 2026-09-29.
Which should you pick?
For a balanced job (1M input + 1M output), DeepSeek V4.1 Flash costs $0.7500 versus $1.40. If your prompts are large and reused, prompt caching changes the maths — the cache-heavy row above shows a 90%-cached input scenario. If your work can run asynchronously, both providers' batch rates cut the bill further where offered.
Full price matrices: GPT-5.6 Luna pricing → · DeepSeek V4.1 Flash pricing → · Back to the LLM pricing hub →