AI Models · Open-Source vs Paid

Step 3.7 Flash Open vs KWKAT-Coder-Pro V2 Paid

Step 3.7 Flash vs KAT-Coder-Pro V2 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.

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
KWKAT-Coder-Pro V2PaidKwaipilot
$0.3 /M input
$1.2 /M outputManaged API (no infra to run)
TypeProprietary
Context window262K tokens
MultimodalNo
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 KAT-Coder-Pro V2 if you want frontier capability through a managed API with zero infrastructure to run.

Step 3.7 Flash vs KAT-Coder-Pro V2 specs

SpecStep 3.7 FlashKAT-Coder-Pro V2Winner
MakerStepfunKwaipilot
TypeOpen-weightProprietaryStep 3.7 Flash
Context window262K tokens262K tokens= Tie
Input price$0.2/M · free self-host$0.3/MStep 3.7 Flash
Output price$1.15/M · free self-host$1.2/MStep 3.7 Flash
Vision / multimodalYesNoStep 3.7 Flash
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Step 3.7 Flash
LicenseOpen weightsProprietaryStep 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 prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
KWChoose KAT-Coder-Pro V2 if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityStep 3.7 FlashKAT-Coder-Pro V2
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Step 3.7 Flash vs KAT-Coder-Pro V2

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

Step 3.7 Flash
KAT-Coder-Pro V2
Intelligence index
19.5
21.7
Coding index
39.6
59.5
GPQA
80.9%
85.5%
Humanity's Last Exam
21.4%
16.1%
Long Context Reasoning
73.7%
73%
SciCode
43.9%
IFBench
67.3%
66.7%
τ²-Bench
98.5%
89.5%
τ-Bench Banking
12%
4.5%
Terminal-Bench
39.3%
70%
Terminal-Bench Hard
35.6%
49.2%
Speed
132.8 tok/s
0 tok/s
Latency
1.59s
0s
Intelligence per $
44.5
41.3

Benchmark data by Artificial Analysis.

How Step 3.7 Flash and KAT-Coder-Pro V2 score

🏆 Best value & openness: Step 3.7 Flash (4.7 vs 2.9 / 5)
CriterionStep 3.7 FlashKAT-Coder-Pro V2
Cost-efficiency4.54.5
Context window4.04.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.03.5

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...

KAT-Coder-Pro V2 Paid

Kwaipilot · Proprietary

KAT-Coder-Pro V2 is the latest high-performance model in KwaiKAT’s KAT-Coder series, designed for complex enterprise-grade software engineering and SaaS integration. It builds on the agentic coding strengths of earlier versions,...

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 KAT-Coder-Pro V2?

Step 3.7 Flash is open-weight and competitive on many tasks, but KAT-Coder-Pro V2 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. KAT-Coder-Pro V2 is API-only and cannot be self-hosted.

Step 3.7 Flash vs KAT-Coder-Pro V2 — 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 KAT-Coder-Pro V2 if you want frontier capability through a managed API with zero infrastructure to run.

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