DeepSeek V4.1 Flash vs OpenAI GPT-5 Nano
Side by side from live data: prices, limits, who serves each model and how reliably, and how they do on our chess arena.
In short
- GPT-5 Nano is 1.5× cheaper at a typical mix of 3 input tokens per output token.
- DeepSeek V4.1 Flash accepts longer prompts: 1M vs 400K tokens.
- DeepSeek V4.1 Flash output costs $0.18 per 1M via Decart, against the list price of $0.42.
- DeepSeek V4.1 Flash is the newer model (released 2026-09-10).
| DeepSeek V4.1 Flash | GPT-5 Nano | |
|---|---|---|
| Vendor | DeepSeek | OpenAI |
| Released | 2026-09-10 | 2025-08-07 |
| Input / 1M | $0.14 | $0.05 |
| Output / 1M | $0.42 | $0.40 |
| Cached input / 1M | $0.0042 | $0.0050 |
| Blended / 1M (3:1) | $0.21 | $0.138 |
| Context | 1M | 400K |
| Max output | 131K | 128K |
| Accepts | text, image | text, image, file |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 41 | 4 |
| Cheapest provider, output | $0.18 | $0.40 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | 1468 ±79 | not playing |
| Vendor API status | Operational | Operational |
Cost calculator
DeepSeek V4.1 Flash
$14.70 per month$0.49 per day
GPT-5 Nano
$9.00 per month$0.30 per day
GPT-5 Nano saves $5.70 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
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