AllocateGemini 3.5 Flash vs OpenAI GPT-OSS 120B
On provider list prices, OpenAI GPT-OSS 120B costs $0.15 per million input tokens against $1.50 for Gemini 3.5 Flash: 10.0x apart. Output is $0.60 against $9 (15.0x). On Allocate both bill at list plus the 7% transaction fee.
Gemini 3.5 Flash
OpenAI GPT-OSS 120BSpecifications 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 $4,950 on Gemini 3.5 Flash at list: a gap of $4,560, or 12.7x.
Gemini 3.5 Flash reads 1M tokens per request against 128K for OpenAI GPT-OSS 120B, 7.6x the window. That decides which one can take whole documents without splitting them.
Choose Gemini 3.5 Flash for
- High-volume support and triage
- Document extraction at scale
- Vision and OCR pipelines
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, Gemini 3.5 Flash 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 $1.50/$9 for Gemini 3.5 Flash. Billed on Allocate: $0.16/$0.64 against $1.60/$9.63, list plus 7%.
Which has the bigger context window?
Gemini 3.5 Flash: 1,000,000 tokens (1M) against 131,072 (128K) for OpenAI GPT-OSS 120B.
Can I fine-tune Gemini 3.5 Flash or OpenAI GPT-OSS 120B?
OpenAI GPT-OSS 120B publishes open weights (Custom license) and can be fine-tuned on your own data. Gemini 3.5 Flash 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.