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comparison

GPT-5.4 mini 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 23× less.

cheaper for a typical workload
gpt-oss-120b
saves 96% vs GPT-5.4 mini at 1,500 in / 500 out × 200,000/mo
GPT-5.4 mini $675/mo
gpt-oss-120b $29.70/mo
GPT-5.4 mini versus gpt-oss-120b specifications and price.
metric GPT-5.4 mini gpt-oss-120b
Input / 1M $0.75 $0.039
Output / 1M $4.50 $0.18
Context 400K 131K
Cost @ typical workload $675/mo $29.70/mo
Modality text + image Text only
Price source list routed
Provider OpenAI 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 GPT-5.4 mini's $675/mo — roughly 23× 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, GPT-5.4 mini has the larger 400K-token window (~600 pages). Only GPT-5.4 mini accepts image input — decisive if your prompts include images.

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 GPT-5.4 mini 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 $675/mo for GPT-5.4 mini — about 23× 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 GPT-5.4 mini and gpt-oss-120b?

On price, GPT-5.4 mini is $0.75/$4.50 per 1M (in/out) and gpt-oss-120b is $0.039/$0.18. GPT-5.4 mini has the larger context window at 400K tokens. GPT-5.4 mini also accepts image input, while gpt-oss-120b is text-only.

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