AI Models · Open-Source vs Paid

Step 3.7 Flash Open vs KWKAT-Coder-Pro V2.5 Paid

Step 3.7 Flash vs KAT-Coder-Pro V2.5 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 V2.5PaidKwaipilot
$0.74 /M input
$2.96 /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 V2.5 if you want frontier capability through a managed API with zero infrastructure to run.

Step 3.7 Flash vs KAT-Coder-Pro V2.5 specs

SpecStep 3.7 FlashKAT-Coder-Pro V2.5Winner
MakerStepfunKwaipilot
TypeOpen-weightProprietaryStep 3.7 Flash
Context window262K tokens262K tokens= Tie
Input price$0.2/M · free self-host$0.74/MStep 3.7 Flash
Output price$1.15/M · free self-host$2.96/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

2.6×cheaper per output token

Step 3.7 Flash is ~2.6× cheaper than KAT-Coder-Pro V2.5 on output tokens ($1.15 vs $2.96 per M tokens).

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 V2.5 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 V2.5
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 V2.5

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

Step 3.7 Flash
KAT-Coder-Pro V2.5
Intelligence index
19.5
Coding index
39.6
GPQA
80.9%
Humanity's Last Exam
21.4%
Long Context Reasoning
73.7%
SciCode
43.9%
IFBench
67.3%
τ²-Bench
98.5%
τ-Bench Banking
12%
Terminal-Bench
39.3%
Terminal-Bench Hard
35.6%
Speed
132.8 tok/s
Latency
1.59s
Intelligence per $
44.5

Benchmark data by Artificial Analysis.

How Step 3.7 Flash and KAT-Coder-Pro V2.5 score

🏆 Best value & openness: Step 3.7 Flash (4.7 vs 2.9 / 5)
CriterionStep 3.7 FlashKAT-Coder-Pro V2.5
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 V2.5 Paid

Kwaipilot · Proprietary

KAT-Coder-Pro V2.5 is a flagship-level Agentic Coding model that can directly hand over an entire issue or an entire business workflow to it, allowing it to autonomously locate and make...

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 V2.5?

Step 3.7 Flash is open-weight and competitive on many tasks, but KAT-Coder-Pro V2.5 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 V2.5 is API-only and cannot be self-hosted.

How much cheaper is Step 3.7 Flash?

Step 3.7 Flash costs $1.15/M output vs $2.96/M for KAT-Coder-Pro V2.5 — roughly 3x cheaper via API, and free if you self-host.

Step 3.7 Flash vs KAT-Coder-Pro V2.5 — 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 V2.5 if you want frontier capability through a managed API with zero infrastructure to run.

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