Model comparison
Step 5 Preview vs Xiaomi MiMo-V2.5-Pro
StepFun against Xiaomi, compared on context, price, and verified benchmark results.
Catalog record checked September 26, 2026Individual provider fields may changeEvidence confidence: High — see receipts below
StepFun
Step 5 Preview
Frontier
Xiaomi
Xiaomi MiMo-V2.5-Pro
Frontier · Open weights
| Specification | Step 5 Preview | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Provider | ||
| Provider | StepFun | Xiaomi |
| Tier | ||
| Tier | Frontier | Frontier |
| Context window | ||
| Context window | 1M | 1M |
| Max output | ||
| Max output | Not verifiedUnverified | Not verifiedUnverified |
| Input / 1M tokens | ||
| Input / 1M tokens | $1 | Winner: $0.435 |
| Output / 1M tokens | ||
| Output / 1M tokens | $2.70 | Winner: $0.87 |
| Weights | ||
| Weights | Closed | Open |
| Parameters | ||
| Parameters | 600B total / 27B active MoE (StepFun) | 1.02T total / 42B active (MoE) |
| Reasoning levels | ||
| Reasoning levels | Not verifiedUnverified | low, high, max |
| Modalities | ||
| Modalities | text, image | text, image |
| License | ||
| License | Not disclosedUnverified | MIT |
| API model id | ||
| API model id | step-5-preview | mimo-v2-5-pro |
| Released | ||
| Released | September 18, 2026 | April 22, 2026 |
| Artificial Analysis Intelligence Index (2026-09-26) | ||
| Artificial Analysis Intelligence Index (2026-09-26) | Winner: 43.7 | 26 |
Prices are USD per million tokens at standard rates, excluding batch and caching discounts. Bold indicates the better figure where one is objectively better. Values we could not confirm from the provider are shown as “Not verified” rather than estimated.
Benchmark receipts
Where each score comes from, and how far it can be compared across models.
- 2026-09-26Artificial Analysis
Composite index blending reasoning, knowledge, and coding evals into one 0–100 score.
Comparable with caveatOnly same-version scores are comparable. v4.3.2 was rebaselined (the top score fell from 66 on v4.1.1 to ~58), so v4.1.1 figures must not be compared with v4.3.2 figures — check measuredAt.
Pricing tiers
Step 5 Preview: $1.00/$2.70 per MTok on the StepFun platform (cache-hit input $0.05); StepFun lists it under Multimodal Reasoning Models and says output tokens include reasoning. No max-output figure is published. StepFun says open weights follow on 2026-10-15. Release date per Artificial Analysis's listing (StepFun's launch page is undated).
Xiaomi MiMo-V2.5-Pro: $0.435/$0.87 per MTok (cache hit $0.0036) after Xiaomi's 2026-05-27 V2.5 price cut — the V2.6 launch post says pricing is unchanged from V2.5. The earlier $1/$3 list and its >256K tier no longer apply. Open weights (MIT). 1.02T/42B active MoE.
Step 5 Preview
Step 5 Preview is StepFun's new frontier reasoning model — a 1M-context, vision-input API preview that lands near Kimi K3 and GLM 5.3 on the Artificial Analysis index at a lower price.
Best for
- Long-context work on a budget
- Chinese + English
- Early testing before the open-weight drop
Watch out
Preview: weights are promised for 2026-10-15 but not yet released, and its max output is unpublished and the launch benchmarks are vendor-run.
Xiaomi MiMo-V2.5-Pro
MiMo-V2.5-Pro is Xiaomi's open-weight (MIT) 1.02T MoE with native multimodal and a 1M context.
Best for
- Open-weight frontier
- Multimodal
- Long-context
Watch out
Verify weights/pricing on your endpoint.
When the cheaper one wins
Xiaomi MiMo-V2.5-Pro is cheaper on output at $0.87 per million tokens against $2.70 for Step 5 Preview — about 3.1×. Use the cheaper tier for classification, extraction, summarisation, and any task where the expensive model’s extra score does not change the accepted output. The expensive one only pays if your hardest task actually fails on the cheap tier. These are standard-tier API rates, excluding batch and cache discounts.
Run the model pickerEvidence confidence: High
How strong and complete the evidence behind this comparison is — not a prediction of which model is better.
- Pricing verified on both sides — Input and output rates are verified for both models.
- 3/5 core specs verified on both sides — Not published for at least one side: max output, reasoning levels.
- 1 shared named benchmark with differing scores — Measured on: Artificial Analysis Intelligence Index.
- Verified within the last 90 days — Newest catalog check was 2 days ago.
- Both models carry source citations — Each side has at least two catalog sources on record.
Source receipts
Each catalog figure was checked against the provider or an independent second source on the date shown.
- Step 5 Preview: StepFun platform pricing (step-5-preview $1.00/$2.70, listed under Multimodal Reasoning Models) (accessed 2026-09-26)
- Step 5 Preview: StepFun — Step 5 Preview launch page (600B/27B MoE, 1M context, vision input) (accessed 2026-09-26)
- Step 5 Preview: Artificial Analysis — Step 5 Preview (release date 2026-09-18) (accessed 2026-09-26)
- Xiaomi MiMo-V2.5-Pro: Xiaomi — MiMo V2.5 (accessed 2026-08-29)
- Xiaomi MiMo-V2.5-Pro: Xiaomi MiMo (accessed 2026-08-29)
- Xiaomi MiMo-V2.5-Pro: Xiaomi — MiMo-V2.6 (API pricing unchanged from V2.5) (accessed 2026-09-26)
Related comparisons
- Claude Fable 5.1 vs Step 5 Preview
- Claude Fable 5.1 vs Xiaomi MiMo-V2.5-Pro
- Claude Fable 5 vs Step 5 Preview
- Claude Fable 5 vs Xiaomi MiMo-V2.5-Pro
- Claude Mythos 5.1 vs Step 5 Preview
- Claude Mythos 5.1 vs Xiaomi MiMo-V2.5-Pro
Diving deeper on one model? Step 5 Preview · Xiaomi MiMo-V2.5-Pro
Common questions
Step 5 Preview vs Xiaomi MiMo-V2.5-Pro
Answered from the verified figures on this page rather than general guidance.
Is Step 5 Preview or Xiaomi MiMo-V2.5-Pro cheaper for input?
Is Step 5 Preview or Xiaomi MiMo-V2.5-Pro cheaper for output?
Which has the larger context window, Step 5 Preview or Xiaomi MiMo-V2.5-Pro?
Should I use Step 5 Preview or Xiaomi MiMo-V2.5-Pro?
Can I self-host Step 5 Preview or Xiaomi MiMo-V2.5-Pro?
Next step
Choosing between them
The verified figures that separate this pair, computed from the catalog rather than restated boilerplate.
- Input price: Xiaomi MiMo-V2.5-Pro costs $0.435 per 1M tokens versus $1 for Step 5 Preview — a 2.3x difference at the headline tier.
- Measured capability: Step 5 Preview leads Artificial Analysis Intelligence Index 43.7 to 26 (measured 2026-09-26).
- Deployment: Xiaomi MiMo-V2.5-Pro publishes weights you can self-host; the other is API-only.
Choosing a harness rather than a model — Cursor, Copilot, Claude Code, Windsurf, or Lovable? Compare agentic harnesses · Latest releases.