DeepSeek V3.1 Terminus vs GPT-5.6 Luna Pro: cost comparison
Prices updated 2026-10-30 · computed from live provider data
Short answer: DeepSeek V3.1 Terminus is cheaper on a
3:1 input/output blend — $0.453 per million tokens versus
$0.608, a 26% difference.
GPT-5.6 Luna Pro offers the larger context window at 1,050,000 tokens, against 163,840 for DeepSeek V3.1 Terminus.
Head to head
| DeepSeek V3.1 Terminus | GPT-5.6 Luna Pro | |
|---|---|---|
| Input, per 1M tokens | $0.270 | $0.270 |
| Output, per 1M tokens | $1.00 | $1.62 |
| Blended 3:1, per 1M | $0.453 | $0.608 |
| Context window | 163,840 | 1,050,000 |
| Vendor | deepseek | kyma |
Monthly cost at real volumes
| Workload (input / output) | DeepSeek V3.1 Terminus | GPT-5.6 Luna Pro |
|---|---|---|
| 1M in / 250K out | $0.520 | $0.676 |
| 10M in / 2.5M out | $5.20 | $6.76 |
| 100M in / 25M out | $52.00 | $67.56 |
Which should you pick?
Pick GPT-5.6 Luna Pro when you need the longer context window (1,050,000 vs 163,840 tokens). Pick DeepSeek V3.1 Terminus when price per token dominates your workload — high-volume classification, extraction, or batch summarisation.