AI Models · Open-Source vs Paid

Step 3.7 Flash Open vs Mistral Medium 3.1 (batch) Paid

Step 3.7 Flash vs Mistral Medium 3.1 (batch) compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Mistral Medium 3.1 (batch) — full profile ›

Prices & specs refreshed from live data · olud.ai

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

Step 3.7 FlashOpenStepfun

$0.2 /M input
$1.15 /M outputNo per-token fees if you self-host

TypeOpen-weight

Context window262K tokens

MultimodalYes

Self-hostYes

Mistral Medium 3.1 (batch)PaidMistral AI

$0.2 /M input
$1 /M outputManaged API (no infra to run)

TypeProprietary

Context window131K tokens

MultimodalYes

Self-hostNo

Choose Step 3.7 Flash 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 Mistral Medium 3.1 (batch) if you want frontier capability through a managed API with zero infrastructure to run.

Step 3.7 Flash vs Mistral Medium 3.1 (batch) specs

Spec	Step 3.7 Flash	Mistral Medium 3.1 (batch)	Winner
Maker	Stepfun	Mistral AI	–
Type	Open-weight	Proprietary	Step 3.7 Flash
Context window	262K tokens	131K tokens	Step 3.7 Flash
Input price	$0.2/M · free self-host	$0.2/M	= Tie
Output price	$1.15/M · free self-host	$1/M	Mistral Medium 3.1 (batch)
Vision / multimodal	Yes	Yes	= Tie
Tool / function calling	Yes	Yes	= Tie
Self-hostable	Yes	No (API only)	Step 3.7 Flash
License	Open weights	Proprietary	Step 3.7 Flash

Price gap & when to choose each

Choose Step 3.7 Flash 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

Choose Mistral Medium 3.1 (batch) if…

You want frontier performance through a managed API
You want the lower output price
You value reliability & ecosystem
You don't want to manage infrastructure

Feature comparison

Capability	Step 3.7 Flash	Mistral Medium 3.1 (batch)
Open weights (downloadable)	✓	✗
Self-hostable	✓	✗
Runs fully offline	✓	✗
Vision / multimodal	✓	✓
Tool / function calling	✓	✓
1M+ context window	✗	✗

Benchmarks: Step 3.7 Flash vs Mistral Medium 3.1 (batch)

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

Step 3.7 Flash delivers 3.6× more intelligence per dollar.

Step 3.7 Flash

Mistral Medium 3.1 (batch)

Intelligence index

19.5

9.9

Coding index

39.6

20.5

GPQA

80.9%

58.8%

Humanity's Last Exam

21.4%

4.7%

Long Context Reasoning

73.7%

–

SciCode

43.9%

32.4%

IFBench

67.3%

39.8%

τ²-Bench

98.5%

40.6%

τ-Bench Banking

12%

8.2%

Terminal-Bench

39.3%

13.9%

Terminal-Bench Hard

35.6%

10.6%

Math index

–

38.3

MMLU-Pro

–

68.3%

LiveCodeBench

–

40.6%

AIME 2025

–

38.3%

Speed

132.8 tok/s

0 tok/s

Latency

1.59s

Intelligence per $

44.5

12.4

Benchmark data by Artificial Analysis.

How Step 3.7 Flash and Mistral Medium 3.1 (batch) score

🏆 Best value & openness: Step 3.7 Flash (4.7 vs 3.1 / 5)

Criterion	Step 3.7 Flash	Mistral Medium 3.1 (batch)
Cost-efficiency	4.5	4.5
Context window	4.0	3.5
Openness	5.0	1.5
Self-hosting	5.0	1.0
Multimodality	5.0	5.0

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

Step 3.7 Flash Open

Stepfun · Open-weight

Step 3.7 Flash is StepFun's latest high-efficiency multimodal Mixture-of-Experts model. It pairs a 196B-parameter language backbone with a vision encoder for native image and video understanding, activating roughly 11B parameters...

Mistral Medium 3.1 (batch) Paid

Mistral AI · Proprietary

Mistral Medium 3.1 is an updated version of Mistral Medium 3, which is a high-performance enterprise-grade language model designed to deliver frontier-level capabilities at significantly reduced operational cost. It balances...

Other models in these families

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

Other variants tracked

Step 3.5 Flash

Frequently asked questions

Is Step 3.7 Flash as good as Mistral Medium 3.1 (batch)?

Step 3.7 Flash is open-weight and competitive on many tasks, but Mistral Medium 3.1 (batch) 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 Step 3.7 Flash locally?

Yes. Step 3.7 Flash has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Mistral Medium 3.1 (batch) is API-only and cannot be self-hosted.

Step 3.7 Flash vs Mistral Medium 3.1 (batch) — which should I pick in 2026?

Choose Step 3.7 Flash 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 Mistral Medium 3.1 (batch) if you want frontier capability through a managed API with zero infrastructure to run.

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