GPT-5.4 Nano vs DeepSeek Flash: current API costs compared
DeepSeek is cheaper on every standard token category off-peak. At peak, Nano has cheaper uncached input, while DeepSeek still has cheaper cached input and output. The request winner depends on timing and token usage.
Compare current cache, output, peak, and batch pricing.
DeepSeek's legacy V4 Flash API name now routes to V4.1 Flash and uses its current prices. GPT-5.4 Nano has fixed standard token rates, while DeepSeek's rates change with UTC peak periods. This comparison uses official USD prices checked on October 7, 2026.
By TechCompare · Updated
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.Provider USD token rates. Cache storage, cache writes, and other service fees aren't included.
Side-by-side specs
| Spec | GPT-5.4 Nano | DeepSeek Flash (V4.1) |
|---|---|---|
| Uncached input per 1M tokens | $0.20 | $0.15 off-peak / $0.30 peak |
| Output per 1M tokens | $1.25 | $0.60 off-peak / $1.20 peak (better on this spec) |
| Cache-hit input per 1M tokens | $0.02 | $0.003 off-peak / $0.006 peak (better on this spec) |
| Batch discount | 50% (better on this spec) | 0% |
How they differ
GPT-5.4 Nano charges $0.20 per million uncached input tokens, $0.02 for cached input, and $1.25 for output. DeepSeek Flash charges $0.15, $0.003, and $0.60 off-peak, or $0.30, $0.006, and $1.20 at peak. Peak periods are 01:00 to 04:00 and 06:00 to 10:00 UTC, Monday through Friday, excluding Chinese public holidays. All other hours are off-peak. For 100K input and 5K output with half the input cached, Nano costs $0.01725 per request versus $0.01065 off-peak or $0.0213 at peak on DeepSeek. At 100 monthly requests, the chart shows $1.725, $1.065, and $2.13 before rounding.
Verdict
DeepSeek no longer wins every base row at every time of day. Off-peak output is about 2.08 times cheaper than Nano standard output, while peak output is only about 4% cheaper. Nano batch rates are $0.10/M input, $0.01/M cached input, and $0.625/M output. Nano batch therefore beats DeepSeek on uncached input in both periods and on output at peak, while DeepSeek retains the lower cache-read rate. Compare complete request costs at the delivery mode and time period you can actually use.
Which should you pick?
Choose GPT-5.4 Nano
OpenAI workflows or asynchronous jobs that can use Nano batch pricing. Nano standard input can also be cheaper for uncached, input-heavy requests during DeepSeek peak hours.
Choose DeepSeek Flash (V4.1)
Workloads that pass your quality checks and reuse cached prefixes, or flexible jobs that can run during DeepSeek off-peak hours. Include billed output and retries in the total.