AI Models · Open-Source vs Open-Source

gpt-oss-120b Open vs Mistral Medium 3.5 (batch) Open

gpt-oss-120b vs Mistral Medium 3.5 (batch) compared — price per token, context window, multimodality, openness and which to choose. 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
Mistral Medium 3.5 (batch)OpenMistral AI
$0.75 /M input
$3.75 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window262K tokens
MultimodalYes
Self-hostYes
Choose gpt-oss-120b for the lower output price ($0.17/M vs $3.75/M). Choose Mistral Medium 3.5 (batch) if you need the larger 262K context window.

gpt-oss-120b vs Mistral Medium 3.5 (batch) specs

Specgpt-oss-120bMistral Medium 3.5 (batch)Winner
MakerOpenAIMistral AI–
TypeOpen-weightOpen-weight–
Context window131K tokens262K tokensMistral Medium 3.5 (batch)
Input price$0.04/M · free self-host$0.75/M · free self-hostgpt-oss-120b
Output price$0.17/M · free self-host$3.75/M · free self-hostgpt-oss-120b
Vision / multimodalNoYesMistral Medium 3.5 (batch)
Tool / function callingYesYes= Tie
Self-hostableYesYes= Tie
LicenseApache 2.0Apache 2.0–

Price gap & when to choose each

22×cheaper per output token

gpt-oss-120b is ~22× cheaper than Mistral Medium 3.5 (batch) on output tokens ($0.17 vs $3.75 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 Mistral Medium 3.5 (batch) if…
  • You want to self-host or run on your cloud
  • You need the longer 262K context window
  • You prioritize data privacy & control
  • You are building open or reproducible AI

Feature comparison

Capabilitygpt-oss-120bMistral Medium 3.5 (batch)
Open weights (downloadable)✓✓
Self-hostable✓✓
Runs fully offline✓✓
Vision / multimodal✗✓
Tool / function calling✓✓
1M+ context window✗✗

Benchmarks: gpt-oss-120b vs Mistral Medium 3.5 (batch)

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

gpt-oss-120b delivers 9.5× more intelligence per dollar.
gpt-oss-120b
Mistral Medium 3.5 (batch)
Intelligence index
11.6
14.2
Coding index
30.4
46.9
Math index
93.4
–
GPQA
78.2%
74.8%
MMLU-Pro
80.8%
–
Humanity's Last Exam
19.6%
13.8%
Long Context Reasoning
52%
69.3%
LiveCodeBench
87.8%
–
SciCode
34%
40.2%
AIME 2025
93.4%
–
IFBench
69%
68.8%
τ²-Bench
65.8%
94.2%
τ-Bench Banking
12.8%
15.1%
Terminal-Bench
26.2%
50.6%
Terminal-Bench Hard
23.5%
33.3%
Speed
195.5 tok/s
159.8 tok/s
Latency
0.52s
0.59s
Intelligence per $
44.6
4.7

Benchmark data by Artificial Analysis.

How gpt-oss-120b and Mistral Medium 3.5 (batch) score

🤝 Neck and neck on these criteria (4.4 vs 4.6 / 5).
Criteriongpt-oss-120bMistral Medium 3.5 (batch)
Cost-efficiency5.04.0
Context window3.54.0
Openness5.05.0
Self-hosting5.05.0
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

Mistral Medium 3.5 (batch) Open

Mistral AI · Open-weight

Mistral Medium 3.5 is a dense 128B instruction-following model from Mistral AI. It supports text and image inputs with text output, and is designed for agentic workflows, coding, and complex...

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
Mistral Large 4Mistral Medium 3.5Mistral Small 4Mistral Small 4 (batch)Mistral Large 3 2512Mistral Large 3 2512 (batch)Mistral Medium 3.1Mistral Medium 3.1 (batch)Mistral Medium 3Devstral 2 2512Mistral Small 3.2 24BMistral Small 3.1 24BMistral LargeMistral Large 2407Mistral Small 3SabaMinistral 3 14B 2512Mixtral 8x22B InstructMinistral 3 8B 2512Ministral 3 8B 2512 (batch)Ministral 3 3B 2512UncensoredCodestral 2508Codestral 2508 (batch)Voxtral Small 24B 2507Mistral Nemo

Frequently asked questions

gpt-oss-120b vs Mistral Medium 3.5 (batch) — which is cheaper?

gpt-oss-120b is cheaper on output ($0.17/M vs $3.75/M).

Which has the larger context window?

Mistral Medium 3.5 (batch) offers the larger context window (262K tokens).

gpt-oss-120b vs Mistral Medium 3.5 (batch) — which should I pick in 2026?

Choose gpt-oss-120b for the lower output price ($0.17/M vs $3.75/M). Choose Mistral Medium 3.5 (batch) if you need the larger 262K context window.

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