comparison
DeepSeek V4 Flash vs gpt-oss-120b
Token pricing, context window and real monthly cost, side by side. gpt-oss-120b is the cheaper of the two for a typical workload — about 2.4× less.
| metric | DeepSeek V4 Flash | gpt-oss-120b |
|---|---|---|
| Input / 1M | $0.14 | $0.039 |
| Output / 1M | $0.28 | $0.18 |
| Context | 1.0M | 131K |
| Cost @ typical workload | $70.00/mo | $29.70/mo |
| Modality | Text only | Text only |
| Price source | first-party | routed |
| Provider | DeepSeek | OpenAI |
Snapshot . Cost uses a typical workload; tune it in the calculator. How we measure →
Which should you pick?
On a typical workload, gpt-oss-120b costs $29.70/mo against DeepSeek V4 Flash's $70.00/mo — roughly 2.4× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, DeepSeek V4 Flash has the larger 1.0M-token window (~1,573 pages).
These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures.
Frequently asked questions
Is DeepSeek V4 Flash or gpt-oss-120b cheaper?
For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), gpt-oss-120b costs $29.70/mo versus $70.00/mo for DeepSeek V4 Flash — about 2.4× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.
What's the main difference between DeepSeek V4 Flash and gpt-oss-120b?
On price, DeepSeek V4 Flash is $0.14/$0.28 per 1M (in/out) and gpt-oss-120b is $0.039/$0.18. DeepSeek V4 Flash has the larger context window at 1.0M tokens.
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- GPT-5.4 nano vs DeepSeek V4 Flash
- Gemini 2.5 Flash-Lite vs gpt-oss-120b
Related
- DeepSeek V4 Flash and gpt-oss-120b — full specs and price history.
- API cost calculator — compare on your own workload.
- All comparisons — the full head-to-head index.