AI Models · Open-Source vs Paid

Step 3.7 Flash Open vs Muse Spark 1.1 Paid

Step 3.7 Flash vs Muse Spark 1.1 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
Muse Spark 1.1PaidMeta
$1.25 /M input
$4.25 /M outputManaged API (no infra to run)
TypeProprietary
Context window1M 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 Muse Spark 1.1 if you want frontier capability through a managed API with zero infrastructure to run.

Step 3.7 Flash vs Muse Spark 1.1 specs

SpecStep 3.7 FlashMuse Spark 1.1Winner
MakerStepfunMeta
TypeOpen-weightProprietaryStep 3.7 Flash
Context window262K tokens1M tokensMuse Spark 1.1
Input price$0.2/M · free self-host$1.25/MStep 3.7 Flash
Output price$1.15/M · free self-host$4.25/MStep 3.7 Flash
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Step 3.7 Flash
LicenseOpen weightsProprietaryStep 3.7 Flash

Price gap & when to choose each

3.7×cheaper per output token

Step 3.7 Flash is ~3.7× cheaper than Muse Spark 1.1 on output tokens ($1.15 vs $4.25 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
Choose Muse Spark 1.1 if…
  • You want frontier performance through a managed API
  • You need the longer 1M context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityStep 3.7 FlashMuse Spark 1.1
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Step 3.7 Flash vs Muse Spark 1.1

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

Step 3.7 Flash delivers 2.6× more intelligence per dollar.
Step 3.7 Flash
Muse Spark 1.1
Intelligence index
19.5
34.3
Coding index
39.6
71.3
GPQA
80.9%
89.8%
Humanity's Last Exam
21.4%
46.2%
Long Context Reasoning
73.7%
77.7%
SciCode
43.9%
58.8%
IFBench
67.3%
τ²-Bench
98.5%
τ-Bench Banking
12%
31.8%
Terminal-Bench
39.3%
77.9%
Terminal-Bench Hard
35.6%
Speed
132.8 tok/s
0 tok/s
Latency
1.59s
0s
Intelligence per $
44.5
17.2

Benchmark data by Artificial Analysis.

How Step 3.7 Flash and Muse Spark 1.1 score

🏆 Best value & openness: Step 3.7 Flash (4.7 vs 3.3 / 5)
CriterionStep 3.7 FlashMuse Spark 1.1
Cost-efficiency4.54.0
Context window4.05.0
Openness5.01.5
Self-hosting5.01.0
Multimodality5.05.0

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...

Muse Spark 1.1 Paid

Meta · Proprietary

Muse Spark 1.1 is a multimodal reasoning model from Meta, built for agentic tasks. It accepts text, images, video, audio, and PDF documents and returns text, with a 1M-token context...

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 Muse Spark 1.1?

Step 3.7 Flash is open-weight and competitive on many tasks, but Muse Spark 1.1 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. Muse Spark 1.1 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 $4.25/M for Muse Spark 1.1 — roughly 4x cheaper via API, and free if you self-host.

Step 3.7 Flash vs Muse Spark 1.1 — 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 Muse Spark 1.1 if you want frontier capability through a managed API with zero infrastructure to run.

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