DeepSeek V4 vs OpenAI GPT-OSS 120B
On provider list prices, OpenAI GPT-OSS 120B costs $0.15 per million input tokens against $1.74 for DeepSeek V4: 11.6x apart. Output is $0.60 against $3.48 (5.8x). On Allocate both bill at list plus the 7% transaction fee.
Specifications and provider list prices from the Allocate catalog, checked 2026-07-08. Billed price is list plus the 7% transaction fee.
What the numbers say
Take 1,000,000 requests a month at 1,200 input and 350 output tokens each. That workload costs $390 a month on OpenAI GPT-OSS 120B and $3,306 on DeepSeek V4 at list: a gap of $2,916, or 8.5x.
DeepSeek V4 reads 512K tokens per request against 128K for OpenAI GPT-OSS 120B, 3.9x the window. That decides which one can take whole documents without splitting them.
Choose DeepSeek V4 for
- Reasoning-heavy agents
- Long-document analysis
- Cost-sensitive production routes
Choose OpenAI GPT-OSS 120B for
- The lower list price ($0.15 in / $0.60 out per M tokens)
- Open weights you can fine-tune and own
Common questions
Which is cheaper, DeepSeek V4 or OpenAI GPT-OSS 120B?
OpenAI GPT-OSS 120B, on this workload shape. At list prices it is $0.15/$0.60 per million tokens in and out against $1.74/$3.48 for DeepSeek V4. Billed on Allocate: $0.16/$0.64 against $1.86/$3.72, list plus 7%.
Which has the bigger context window?
DeepSeek V4: 512,000 tokens (512K) against 131,072 (128K) for OpenAI GPT-OSS 120B.
Can I fine-tune DeepSeek V4 or OpenAI GPT-OSS 120B?
OpenAI GPT-OSS 120B publishes open weights (Custom license) and can be fine-tuned on your own data. DeepSeek V4 is a closed model served over API; its weights are not available.
Related comparisons
Run the numbers on your workload
Or don’t choose. On Allocate a route name is the contract: point yours at one model today, swap to the other tomorrow, and compare them on your live traffic with per-token metering.