AI Models · Open-Source vs Paid

gpt-oss-120b Open vs o3 Paid

gpt-oss-120b vs o3 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

gpt-oss-120bOpenOpenAI
$0.04 /M input
$0.17 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window131K tokens
MultimodalNo
Self-hostYes
o3PaidOpenAI
$2 /M input
$8 /M outputManaged API (no infra to run)
TypeProprietary
Context window200K tokens
MultimodalYes
Self-hostNo
Choose gpt-oss-120b if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose o3 if you want frontier capability through a managed API with zero infrastructure to run.

gpt-oss-120b vs o3 specs

Specgpt-oss-120bo3Winner
MakerOpenAIOpenAI–
TypeOpen-weightProprietarygpt-oss-120b
Context window131K tokens200K tokenso3
Input price$0.04/M · free self-host$2/Mgpt-oss-120b
Output price$0.17/M · free self-host$8/Mgpt-oss-120b
Vision / multimodalNoYeso3
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)gpt-oss-120b
LicenseApache 2.0Proprietarygpt-oss-120b

Price gap & when to choose each

47×cheaper per output token

gpt-oss-120b is ~47× cheaper than o3 on output tokens ($0.17 vs $8 per M tokens).

Choose gpt-oss-120b if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose o3 if…
  • You want frontier performance through a managed API
  • You need the longer 200K context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

Capabilitygpt-oss-120bo3
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✗✓
Tool / function calling✓✓
1M+ context window✗✗

Benchmarks: gpt-oss-120b vs o3

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

gpt-oss-120b delivers 7.7× more intelligence per dollar.
gpt-oss-120b
o3
Intelligence index
11.6
20.2
Coding index
30.4
–
Math index
93.4
88.3
GPQA
78.2%
82.7%
MMLU-Pro
80.8%
85.3%
Humanity's Last Exam
19.6%
20.1%
Long Context Reasoning
52%
74.7%
LiveCodeBench
87.8%
80.8%
SciCode
34%
–
AIME 2025
93.4%
88.3%
IFBench
69%
71.4%
τ²-Bench
65.8%
80.7%
τ-Bench Banking
12.8%
–
Terminal-Bench
26.2%
–
Terminal-Bench Hard
23.5%
37.1%
MATH-500
–
99.2%
AIME
–
90.3%
Speed
199.8 tok/s
140 tok/s
Latency
0.5s
4.49s
Intelligence per $
44.4
5.8

Benchmark data by Artificial Analysis.

How gpt-oss-120b and o3 score

🏆 Best value & openness: gpt-oss-120b (4.4 vs 3.0 / 5)
Criteriongpt-oss-120bo3
Cost-efficiency5.03.5
Context window3.54.0
Openness5.01.5
Self-hosting5.01.0
Multimodality3.55.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

gpt-oss-120b Open

OpenAI · Open-weight

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 optimize

o3 Paid

OpenAI · Proprietary

o3 is a well-rounded and powerful model across domains. It sets a new standard for math, science, coding, and visual reasoning tasks. It also excels at technical writing and instruction-following....

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
gpt-oss-120b (batch)gpt-oss-20b (batch)gpt-oss-20bgpt-oss-safeguard-20b
Other variants tracked
o3 Proo3 (batch)o3 Minio3 Mini (batch)o3 Mini High

Frequently asked questions

Is gpt-oss-120b as good as o3?

gpt-oss-120b is open-weight and competitive on many tasks, but o3 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run gpt-oss-120b locally?

Yes. gpt-oss-120b has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. o3 is API-only and cannot be self-hosted.

How much cheaper is gpt-oss-120b?

gpt-oss-120b costs $0.17/M output vs $8/M for o3 — roughly 47x cheaper via API, and free if you self-host.

gpt-oss-120b vs o3 — which should I pick in 2026?

Choose gpt-oss-120b if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose o3 if you want frontier capability through a managed API with zero infrastructure to run.

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