AI Models · Open-Source vs Paid

Step 5 Preview Open vs XIMiMo-V2.6-Pro-UltraSpeed Paid

Step 5 Preview vs MiMo-V2.6-Pro-UltraSpeed 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
XIMiMo-V2.6-Pro-UltraSpeedPaidXiaomi
$4.35 /M input
$8.7 /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 MiMo-V2.6-Pro-UltraSpeed if you want frontier capability through a managed API with zero infrastructure to run.

Step 5 Preview vs MiMo-V2.6-Pro-UltraSpeed specs

SpecStep 5 PreviewMiMo-V2.6-Pro-UltraSpeedWinner
MakerStepfunXiaomi–
TypeOpen-weightProprietaryStep 5 Preview
Context window1M tokens1M tokens= Tie
Input price$1/M · free self-host$4.35/MStep 5 Preview
Output price$2.7/M · free self-host$8.7/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

3.2×cheaper per output token

Step 5 Preview is ~3.2× cheaper than MiMo-V2.6-Pro-UltraSpeed on output tokens ($2.7 vs $8.7 per M tokens).

Choose Step 5 Preview 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
XIChoose MiMo-V2.6-Pro-UltraSpeed if…
  • You want frontier performance through a managed API
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityStep 5 PreviewMiMo-V2.6-Pro-UltraSpeed
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✓✓
Tool / function calling✓✓
1M+ context window✓✓

Benchmarks: Step 5 Preview vs MiMo-V2.6-Pro-UltraSpeed

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

Step 5 Preview
MiMo-V2.6-Pro-UltraSpeed
Intelligence index
43.7
–
Humanity's Last Exam
46.5%
–
Long Context Reasoning
88.3%
–
SciCode
58.9%
–
Speed
93.9 tok/s
–
Latency
1.37s
–
Intelligence per $
30.7
–

Benchmark data by Artificial Analysis.

How Step 5 Preview and MiMo-V2.6-Pro-UltraSpeed score

🏆 Best value & openness: Step 5 Preview (4.9 vs 3.2 / 5)
CriterionStep 5 PreviewMiMo-V2.6-Pro-UltraSpeed
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...

MiMo-V2.6-Pro-UltraSpeed Paid

Xiaomi · Proprietary

MiMo-V2.6-Pro-UltraSpeed is the fast speed edition of Xiaomi's flagship foundation model, MiMo-V2.6-Pro. Built from the same 1T MiMo-V2.6-Pro checkpoint, it matches the original model in quality while delivering roughly 10x...

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

Frequently asked questions

Is Step 5 Preview as good as MiMo-V2.6-Pro-UltraSpeed?

Step 5 Preview is open-weight and competitive on many tasks, but MiMo-V2.6-Pro-UltraSpeed 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. MiMo-V2.6-Pro-UltraSpeed is API-only and cannot be self-hosted.

How much cheaper is Step 5 Preview?

Step 5 Preview costs $2.7/M output vs $8.7/M for MiMo-V2.6-Pro-UltraSpeed — roughly 3x cheaper via API, and free if you self-host.

Step 5 Preview vs MiMo-V2.6-Pro-UltraSpeed — 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 MiMo-V2.6-Pro-UltraSpeed if you want frontier capability through a managed API with zero infrastructure to run.

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