gpt-oss-120b vs OpenAI o4-mini

Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.

gpt-oss-120b

OpenAI · Aug 2025

OpenAI's open-weights MoE reasoning model under Apache 2.0 — near o4-mini quality, runnable on a single 80GB GPU.

OpenAI o4-mini

OpenAI · Apr 2025

80.9

A compact reasoning model that punched far above its price on math — 92.7% on AIME 2025 at $1.10 per million input tokens.

The verdict

OpenAI o4-mini wins 2 of the 2 benchmarks these models share, against 0 for gpt-oss-120b. On price the gap is dramatic: gpt-oss-120b works out roughly 9.6x cheaper per blended million tokens. OpenAI o4-mini also takes 200K 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.

Benchmark head-to-head 02

GPQA Diamond
80.1%81.4%
gpt-oss-120bOpenAI o4-mini
AIME 2025
~92.5%92.7%
gpt-oss-120bOpenAI o4-mini

Specs & pricing

gpt-oss-120bOpenAI o4-mini
modhub Index80.9
Input price / 1M$0.1$1.1
Output price / 1M$0.5$4.4
Context window131K200K
Max output131K100K
Open weightsyes (Apache 2.0)no
Reasoning modelyesyes
Multimodal inputtexttext, image
Knowledge cutoffJun 2024May 2024
ReleasedAug 2025Apr 2025
Example monthly cost*$1.75$17.60

* 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 OpenAI o4-mini?
OpenAI o4-mini wins 2 of the 2 benchmarks these models share, against 0 for gpt-oss-120b. On price the gap is dramatic: gpt-oss-120b works out roughly 9.6x cheaper per blended million tokens. OpenAI o4-mini also takes 200K 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 OpenAI o4-mini?
gpt-oss-120b costs $0.1/$0.5 per million input/output tokens, while OpenAI o4-mini costs $1.1/$4.4. For a typical workload of 10M input and 1.5M output tokens per month, that's $1.75 versus $17.60.
Which model is better for coding, gpt-oss-120b or OpenAI o4-mini?
We don't yet track SWE-bench Verified results for both models; check their individual pages for coding-related scores.

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