gpt-oss-120b vs Grok 4.1 Fast
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
OpenAI · Aug 2025
OpenAI's open-weights MoE reasoning model under Apache 2.0 — near o4-mini quality, runnable on a single 80GB GPU.
xAI · Nov 2025
A 2M-token context window for $0.20 per million input tokens — the cheapest long-context frontier offering anywhere.
The verdict
These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. gpt-oss-120b is about 1.4x cheaper per blended million tokens (3:1 input:output mix). Grok 4.1 Fast also takes 2M of context versus 131K for gpt-oss-120b. And gpt-oss-120b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
Specs & pricing
| gpt-oss-120b | Grok 4.1 Fast | |
|---|---|---|
| modhub Index | — | — |
| Input price / 1M | $0.1 | $0.2 |
| Output price / 1M | $0.5 | $0.5 |
| Context window | 131K | 2M |
| Max output | 131K | — |
| Open weights | yes (Apache 2.0) | no |
| Reasoning model | yes | yes |
| Multimodal input | text | text, image |
| Knowledge cutoff | Jun 2024 | Nov 2025 |
| Released | Aug 2025 | Nov 2025 |
| Example monthly cost* | $1.75 | $2.75 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, gpt-oss-120b or Grok 4.1 Fast?
- These two models don't yet share verified results on the benchmarks we track, so judge them on specs, pricing and intended use. gpt-oss-120b is about 1.4x cheaper per blended million tokens (3:1 input:output mix). Grok 4.1 Fast also takes 2M of context versus 131K for gpt-oss-120b. And gpt-oss-120b is open-weights (Apache 2.0), so it can be self-hosted — a structural advantage if data control or vendor independence matters.
- Which is cheaper, gpt-oss-120b or Grok 4.1 Fast?
- gpt-oss-120b costs $0.1/$0.5 per million input/output tokens, while Grok 4.1 Fast costs $0.2/$0.5. For a typical workload of 10M input and 1.5M output tokens per month, that's $1.75 versus $2.75.
- Which model is better for coding, gpt-oss-120b or Grok 4.1 Fast?
- We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.