API cost decision in 10 seconds

gpt-oss-120b (free) vs o3 Mini

Pick gpt-oss-120b (free) for lower cost; pick o3 Mini only if the larger context window matters more.

Page updated:  Data confirmed:  Prices normalized to USD per 1M tokens Sample workload: 1M input + 500K output

Budget verdict

Pick gpt-oss-120b (free) for lower cost; pick o3 Mini only if the larger context window matters more.

On the standard 1M input plus 500K output workload, gpt-oss-120b (free) is estimated at $0 vs $3.3 for o3 Mini, saving $3.3 (100% lower).

Cost-first pickgpt-oss-120b (free)
Context-first picko3 Mini
Sample savings$3.3100%
10x traffic gap$33

o3 Mini has more context, but gpt-oss-120b (free) saves $3.3 on the standard workload. At 10x that traffic, the same price gap is about $33. Use the calculator below to replace the sample workload with your own token volume.

Cost sensitivity

Workload Sensitivity

Same prices, different token mixes.

gpt-oss-120b (free) stays cheaper across input-heavy, balanced, and output-heavy sample workloads.

Workload shapeToken mixBetter pickgpt-oss-120b (free)o3 Mini
Input-heavy / RAG5M input + 500K outputgpt-oss-120b (free)$0$7.7
Balanced workload1M input + 1M outputgpt-oss-120b (free)$0$5.5
Output-heavy chatbot1M input + 5M outputgpt-oss-120b (free)$0$23.1
Cheaper input gpt-oss-120b (free) $0 vs $1.1 / 1M

gpt-oss-120b (free) is free for input tokens while o3 Mini costs $1.1 per 1M tokens.

Cheaper output gpt-oss-120b (free) $0 vs $4.4 / 1M

gpt-oss-120b (free) is free for output tokens while o3 Mini costs $4.4 per 1M tokens.

Larger context o3 Mini 131.07K vs 200K

o3 Mini has 68.93K more context (1.53x larger).

Sample workload gpt-oss-120b (free) $0 vs $3.3

gpt-oss-120b (free) is free for the standard workload while the other model is estimated at $3.3.

Estimate your workload cost

Your Workload Cost

Prices are normalized to USD per 1M tokens.
gpt-oss-120b (free) Calculating… Estimated API cost
o3 Mini Calculating… Estimated API cost
Cheaper for this workload Calculating… Difference: calculating…

This estimate uses normalized public API pricing per 1M tokens. It is a planning aid, not a billing quote. Verify provider pricing, limits, and terms before production use.

Quick Decision

Verdict

gpt-oss-120b (free) has the lower input price; gpt-oss-120b (free) has the lower output price; o3 Mini offers the larger context window. For the 1M input plus 500K output sample, gpt-oss-120b (free) is cheaper for the standard workload.

For a 1M input token plus 500K output token workload, the estimated API cost is $0 for gpt-oss-120b (free) and $3.3 for o3 Mini.

Best Fit

Choose gpt-oss-120b (free) when you care most about lower input-token price, and lower output-token price.

Choose o3 Mini when you care most about larger context window.

Decision Notes
  • On the standard 1M input plus 500K output workload, gpt-oss-120b (free) is estimated at $0 vs $3.3 for o3 Mini, saving $3.3 (100% lower).
  • gpt-oss-120b (free) is free for the standard workload while the other model is estimated at $3.3.
  • gpt-oss-120b (free) is free for input tokens while o3 Mini costs $1.1 per 1M tokens.
  • gpt-oss-120b (free) is free for output tokens while o3 Mini costs $4.4 per 1M tokens.
  • o3 Mini has 68.93K more context (1.53x larger).
Head-to-Head Specs
Featuregpt-oss-120b (free)
(OpenAI)		o3 Mini
(OpenAI)
Input Price
prompt tokens per 1M		$0$1.1
Completion Price
per 1M tokens		$0$4.4
Sample Workload Cost
1M input + 500K output		$0$3.3
Context Window131.07K200K
Release Date
Popularity#26#120

Use-Case Decision Matrix

Use caseBetter pickWhy
Budget-constrained productiongpt-oss-120b (free)On the standard 1M input plus 500K output workload, gpt-oss-120b (free) is estimated at $0 vs $3.3 for o3 Mini, saving $3.3 (100% lower).
High-volume input processinggpt-oss-120b (free)Lower prompt-token price matters most when prompts, retrieved passages, or documents dominate the bill.
Long responses and chatbotsgpt-oss-120b (free)Lower output-token price matters most when assistants generate many completion tokens.
RAG or long-document worko3 MiniA larger context window leaves more room for retrieved passages, conversation history, or source files.

Related Alternatives

Same-provider lower-cost swaps
  • gpt-oss-20b (free) can replace o3 Mini when lower sample workload cost matters most: $0.
  • gpt-oss-20b can replace o3 Mini when lower sample workload cost matters most: $0.1.
  • gpt-oss-120b can replace o3 Mini when lower sample workload cost matters most: $0.13.
  • gpt-oss-safeguard-20b can replace o3 Mini when lower sample workload cost matters most: $0.22.
Larger context near this budget
  • Llama 4 Scout offers 10M context with $0.23 sample workload cost.
  • Grok 4.20 offers 2M context with $2.5 sample workload cost.
  • Owl Alpha offers 1.05M context with $0 sample workload cost.
  • DeepSeek V4 Flash offers 1.05M context with $0.2 sample workload cost.

Cheaper alternatives

Review low-cost models sorted by a standard 1M input plus 500K output workload.

Open cheapest models

Larger context alternatives

Find models with larger context windows for RAG, long documents, and codebase review.

Open largest context models

Provider catalogs

Compare models within provider hubs before choosing a final API vendor.

Open provider hubs

OpenAI catalog

Review all tracked OpenAI models before deciding whether this matchup is the right shortlist.

Open OpenAI models
gpt-oss-120b (free)

gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimized...

o3 Mini

OpenAI o3-mini is a cost-efficient language model optimized for STEM reasoning tasks, particularly excelling in science, mathematics, and coding. This model supports the `reasoning_effort` parameter, which can be set to...