AI Models · Open-Source vs Paid

Step 5 Preview Open vs GPT-4.1 Paid

Step 5 Preview vs GPT-4.1 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 5 PreviewOpenStepfun
$1 /M input
$2.7 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window1M tokens
MultimodalYes
Self-hostYes
GPT-4.1PaidOpenAI
$2 /M input
$8 /M outputManaged API (no infra to run)
TypeProprietary
Context window1M tokens
MultimodalYes
Self-hostNo
Choose Step 5 Preview 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 GPT-4.1 if you want frontier capability through a managed API with zero infrastructure to run.

Step 5 Preview vs GPT-4.1 specs

SpecStep 5 PreviewGPT-4.1Winner
MakerStepfunOpenAI–
TypeOpen-weightProprietaryStep 5 Preview
Context window1M tokens1M tokensStep 5 Preview
Input price$1/M · free self-host$2/MStep 5 Preview
Output price$2.7/M · free self-host$8/MStep 5 Preview
Vision / multimodalYesYes= Tie
Tool / function callingYesYes= Tie
Self-hostableYesNo (API only)Step 5 Preview
LicenseOpen weightsProprietaryStep 5 Preview

Price gap & when to choose each

3.0×cheaper per output token

Step 5 Preview is ~3.0× cheaper than GPT-4.1 on output tokens ($2.7 vs $8 per M tokens).

Choose Step 5 Preview if…
  • You want to self-host or run on your cloud
  • You need the longer 1M context window
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose GPT-4.1 if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityStep 5 PreviewGPT-4.1
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Step 5 Preview vs GPT-4.1

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

Step 5 Preview delivers 8.5× more intelligence per dollar.
Step 5 Preview
GPT-4.1
Intelligence index
43.7
12.7
Humanity's Last Exam
46.5%
4.2%
Long Context Reasoning
88.3%
68.3%
SciCode
58.9%
–
Math index
–
34.7
GPQA
–
66.6%
MMLU-Pro
–
80.6%
LiveCodeBench
–
45.7%
MATH-500
–
91.3%
AIME
–
43.7%
AIME 2025
–
34.7%
IFBench
–
43%
τ²-Bench
–
47.1%
Terminal-Bench Hard
–
13.6%
Speed
201.5 tok/s
0 tok/s
Latency
0.87s
0s
Intelligence per $
30.7
3.6

Benchmark data by Artificial Analysis.

How Step 5 Preview and GPT-4.1 score

🏆 Best value & openness: Step 5 Preview (4.9 vs 3.2 / 5)
CriterionStep 5 PreviewGPT-4.1
Cost-efficiency4.53.5
Context window5.05.0
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 5 Preview Open

Stepfun · Open-weight

Step 5 Preview is StepFun's flagship model for agentic work, built on a sparse Mixture-of-Experts architecture (27B active / 600B total parameters). It performs strongly in software engineering and professional...

GPT-4.1 Paid

OpenAI · Proprietary

GPT-4.1 is a flagship large language model optimized for advanced instruction following, real-world software engineering, and long-context reasoning. It supports a 1 million token context window and outperforms GPT-4o and...

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 3.7 FlashStep 3.5 Flash
Other variants tracked
GPT-4.1 (batch)GPT-4.1 MiniGPT-4.1 Mini (batch)GPT-4.1 NanoGPT-4.1 Nano (batch)

Frequently asked questions

Is Step 5 Preview as good as GPT-4.1?

Step 5 Preview is open-weight and competitive on many tasks, but GPT-4.1 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 5 Preview locally?

Yes. Step 5 Preview has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-4.1 is API-only and cannot be self-hosted.

How much cheaper is Step 5 Preview?

Step 5 Preview costs $2.7/M output vs $8/M for GPT-4.1 — roughly 3x cheaper via API, and free if you self-host.

Step 5 Preview vs GPT-4.1 — which should I pick in 2026?

Choose Step 5 Preview 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 GPT-4.1 if you want frontier capability through a managed API with zero infrastructure to run.

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