Step 5 Preview vs MiMo-V2.5-Pro
Step 5 Preview leads MiMo-V2.5-Pro on coding, 61.1 to 31.6 on the Vibe Coding Index, and MiMo-V2.5-Pro costs 3.0x less per output token ($0.9152 vs $2.70 per million). Updated October 22, 2026; 40 benchmarks have a result for both.
Step 5 Preview or MiMo-V2.5-Pro: which to pick
Pick Step 5 Preview for coding: it scores 61.1 on the Vibe Coding Index against 31.6 for MiMo-V2.5-Pro.
Pick MiMo-V2.5-Pro for output tokens 3.0x cheaper ($0.9152 vs $2.70 per million) and a larger context window (1.05M against 1.05M tokens).
- Shared results
- 40
- Step 5 Preview only
- 21
- MiMo-V2.5-Pro only
- 30
- Like-for-like categories
- 7 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
Step 5 Preview
Step 5 Preview scores 61.1 against 31.6.
4 benchmarks behind each score
Intelligence
AA Intelligence Index
Step 5 Preview
Step 5 Preview leads, 43.7 against 26.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only MiMo-V2.5-Pro has a AA Agentic Index result, 21.3.
Directional only
Reasoning
GPQA Diamond
No call
Only MiMo-V2.5-Pro has a GPQA Diamond result, 82.6%.
Directional only
Knowledge
MMLU Pro
No call
Only MiMo-V2.5-Pro has a MMLU Pro result, 84.6%.
Directional only
Web design
Design Arena: websites
No call
Only MiMo-V2.5-Pro has a Design Arena: websites result, 1266.
Directional only
Long documents
Listed context window
MiMo-V2.5-Pro
MiMo-V2.5-Pro takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
MiMo-V2.5-Pro
Step 5 Preview $0.0024, MiMo-V2.5-Pro $0.0009 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only MiMo-V2.5-Pro has the number, $0.03.
Directional only
At a glance
- Coding index
- Step 5 Preview 61.1 from 4 benchmarks, MiMo-V2.5-Pro 31.6 from 4 benchmarks.
- Widest category
- Intelligence, 17.7 points apart on average over 1 shared benchmark.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Step 5 Preview 31.8% against MiMo-V2.5-Pro 0.5%, 41.7 points apart on a 0 to 100 scale.
- Output price
- Step 5 Preview $2.70 against MiMo-V2.5-Pro $0.9152 per million output tokens, 3.0x apart.
- Context window
- Step 5 Preview takes 1.05M tokens, MiMo-V2.5-Pro 1.05M.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Step 5 Preview | Bars | MiMo-V2.5-Pro | Ties |
|---|---|---|---|---|
| Coding | 7 | 2 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 4 | 0 | ||
| Reasoning | 1 | 3 | ||
| Math | 1 | 2 | ||
| Knowledge | 0 | 4 | ||
| General | 1 | 14 | ||
| All shared boards | 15 | 25 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index72
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| LiveBench coding | 85.6% | Not measured | Only Step 5 Preview measured |
| LMArena WebDev | 1567 | 1480 | Step 5 Preview |
| AA Coding Index | Not measured | 60.2 | Only MiMo-V2.5-Pro measured |
| LiveCodeBench (Vals AI) | Not measured | 81.3% | Only MiMo-V2.5-Pro measured |
| SWE-bench Verified (Vals AI) | Not measured | 74.0% | Only MiMo-V2.5-Pro measured |
| Terminal-Bench 4 (Vals AI) | 31.8% | 0.5% | Step 5 Preview |
| Vibe Code Bench (Vals AI) | 70.4% | 34.1% | Step 5 Preview |
| Code migration (Vals AI) | 39.0% | 21.6% | Step 5 Preview |
| IOI (Vals AI) | 38.1% | Not measured | Only Step 5 Preview measured |
| Terminal-Bench 2.1 (Vals AI) | Not measured | 57.3% | Only MiMo-V2.5-Pro measured |
| SWE-bench Multimodal (Vals AI) | 40.8% | Not measured | Only Step 5 Preview measured |
| SciCode | 58.9% | 50.6% | Step 5 Preview |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 43.2% | Only MiMo-V2.5-Pro measured |
| ALE-Bench | Not measured | 899.8 | Only MiMo-V2.5-Pro measured |
| LMArena Text: coding | 1485 | 1501 | MiMo-V2.5-Pro |
| LMArena Text: software and IT | 1473 | 1495 | MiMo-V2.5-Pro |
| LMArena WebDev: React | 1583 | 1469 | Step 5 Preview |
| LMArena WebDev: HTML | 1556 | 1473 | Step 5 Preview |
| LMArena WebDev: from an image | 1550 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 20 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| AA Intelligence Index | 43.7 | 26.0 | Step 5 Preview |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 21.3 | Only MiMo-V2.5-Pro measured |
| LiveBench research | 72.8% | Not measured | Only Step 5 Preview measured |
| LiveBench browser | 24.0% | Not measured | Only Step 5 Preview measured |
| LiveBench long agentic | 27.5% | Not measured | Only Step 5 Preview measured |
| SREBench (Vals AI) | 0.4% | Not measured | Only Step 5 Preview measured |
| Finance Agent (Vals AI) | 50.7% | 41.5% | Step 5 Preview |
| Tax Agent Bench (Vals AI) | 27.3% | 11.5% | Step 5 Preview |
| Legal Research Bench (Vals AI) | 40.4% | 15.9% | Step 5 Preview |
| Excel Modeling Benchmark (Vals AI) | 57.1% | 55.2% | Step 5 Preview |
| BioMysteryBench (Vals AI) | 67.4% | Not measured | Only Step 5 Preview measured |
| Terminal-Bench-Science (Vals AI) | 2.9% | Not measured | Only Step 5 Preview measured |
| Vals Science Index | 29.6% | Not measured | Only Step 5 Preview measured |
| τ²-Bench Telecom | Not measured | 94.2% | Only MiMo-V2.5-Pro measured |
| Neither model has a result on the other 28 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index13
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 82.6% | Only MiMo-V2.5-Pro measured |
| LiveBench reasoning | 83.8% | Not measured | Only Step 5 Preview measured |
| MysteryMechanism (Vals AI) | 18.5% | Not measured | Only Step 5 Preview measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 86.6% | Only MiMo-V2.5-Pro measured |
| Humanity's Last Exam (Artificial Analysis run) | 46.5% | 35.7% | Step 5 Preview |
| LMArena Text: hard prompts | 1461 | 1486 | MiMo-V2.5-Pro |
| LMArena Text: expert | 1485 | 1501 | MiMo-V2.5-Pro |
| LMArena Text: hard prompts in English | 1454 | 1494 | MiMo-V2.5-Pro |
| LMArena Vision: diagrams | 1308 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: homework | 1265 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 12 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| ProofBench | 42.0% | 22.0% | Step 5 Preview |
| LMArena Text: math | 1458 | 1481 | MiMo-V2.5-Pro |
| LMArena Text: mathematical work | 1460 | 1491 | MiMo-V2.5-Pro |
| Neither model has a result on the other 10 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 84.6% | Only MiMo-V2.5-Pro measured |
| LegalBench (Vals AI) | Not measured | 77.1% | Only MiMo-V2.5-Pro measured |
| CorpFin (Vals AI) | Not measured | 61.4% | Only MiMo-V2.5-Pro measured |
| TaxEval (Vals AI) | Not measured | 73.8% | Only MiMo-V2.5-Pro measured |
| MedCode (Vals AI) | Not measured | 32.5% | Only MiMo-V2.5-Pro measured |
| LMArena Text: science | 1454 | 1482 | MiMo-V2.5-Pro |
| LMArena Text: medicine and healthcare | 1439 | 1473 | MiMo-V2.5-Pro |
| LMArena Text: legal and government | 1437 | 1474 | MiMo-V2.5-Pro |
| LMArena Text: business and finance | 1435 | 1466 | MiMo-V2.5-Pro |
| Neither model has a result on the other 9 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index9 boards, none shared
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1266 | Only MiMo-V2.5-Pro measured |
| Design Arena: UI components | Not measured | 1246 | Only MiMo-V2.5-Pro measured |
| Design Arena: game dev | Not measured | 1261 | Only MiMo-V2.5-Pro measured |
| Design Arena: data viz | Not measured | 1257 | Only MiMo-V2.5-Pro measured |
| Design Arena: 3D | Not measured | 1243 | Only MiMo-V2.5-Pro measured |
| Design Arena: all code categories | Not measured | 1265 | Only MiMo-V2.5-Pro measured |
| Design Arena: SVG | Not measured | 1181 | Only MiMo-V2.5-Pro measured |
| Design Arena: ASCII art | Not measured | 1156 | Only MiMo-V2.5-Pro measured |
| LiveBench design | 76.9% | Not measured | Only Step 5 Preview measured |
GeneralLike-for-likePublic boards, shown as published, kept out of the index114
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| LiveBench data analysis | 63.5% | Not measured | Only Step 5 Preview measured |
| Public Benefits Bench (Vals AI) | 58.1% | Not measured | Only Step 5 Preview measured |
| MedScribe (Vals AI) | Not measured | 83.7% | Only MiMo-V2.5-Pro measured |
| IFBench | Not measured | 79.9% | Only MiMo-V2.5-Pro measured |
| Long context reasoning (AA-LCR) | 88.3% | 79.7% | Step 5 Preview |
| DTBench | Not measured | 84.5% | Only MiMo-V2.5-Pro measured |
| LMCA | Not measured | 29.5% | Only MiMo-V2.5-Pro measured |
| LMArena Text | 1440 | 1464 | MiMo-V2.5-Pro |
| LMArena Text: instruction following | 1438 | 1475 | MiMo-V2.5-Pro |
| LMArena Text: creative writing | 1409 | 1438 | MiMo-V2.5-Pro |
| LMArena Vision | 1265 | Not measured | Only Step 5 Preview measured |
| LMArena Text: English | 1447 | 1477 | MiMo-V2.5-Pro |
| LMArena Text: non-English | 1428 | 1448 | MiMo-V2.5-Pro |
| LMArena Text: Chinese | 1500 | 1507 | MiMo-V2.5-Pro |
| LMArena Text: German | Not measured | 1459 | Only MiMo-V2.5-Pro measured |
| LMArena Text: Japanese | 1383 | 1410 | MiMo-V2.5-Pro |
| LMArena Text: Korean | Not measured | 1435 | Only MiMo-V2.5-Pro measured |
| LMArena Text: French | 1438 | 1487 | MiMo-V2.5-Pro |
| LMArena Text: Spanish | 1441 | 1469 | MiMo-V2.5-Pro |
| LMArena Text: Russian | 1433 | 1449 | MiMo-V2.5-Pro |
| LMArena Text: Polish | Not measured | 1464 | Only MiMo-V2.5-Pro measured |
| LMArena Text: multi-turn | 1437 | 1476 | MiMo-V2.5-Pro |
| LMArena Text: longer queries | 1449 | 1481 | MiMo-V2.5-Pro |
| LMArena Text: writing and language | 1425 | 1451 | MiMo-V2.5-Pro |
| LMArena Text: entertainment and media | 1412 | 1438 | MiMo-V2.5-Pro |
| LMArena Vision: English | 1290 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: reading text | 1282 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 19 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Step 5 Preview | MiMo-V2.5-Pro | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
MiMo-V2.5-Pro costs less
Repository review
50K input + 3K output tokens
MiMo-V2.5-Pro costs less
Agent loop
200K input + 10K output tokens
MiMo-V2.5-Pro costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | StepFun Step 5 Preview | Xiaomi MiMo-V2.5-Pro |
|---|---|---|
| Maker | StepFun | Xiaomi |
| Weights | Open weights | Open weights |
| Released | October 8, 2026 | April 22, 2026 |
| Context window | 1.05M | 1.05M |
| Input $/Mtok | $1.00 | $0.4575 |
| Output $/Mtok | $2.70 | $0.9152 |
| Coding index | 61.1 | 31.6 |
| Independent measurements behind it | 4 | 4 |
| Cost per solved task | Not computable | $0.03 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Step 5 Preview better than MiMo-V2.5-Pro for coding?
Pick Step 5 Preview for coding: it scores 61.1 on the Vibe Coding Index against 31.6 for MiMo-V2.5-Pro. Pick MiMo-V2.5-Pro for output tokens 3.0x cheaper ($0.9152 vs $2.70 per million) and a larger context window (1.05M against 1.05M tokens).
Which is cheaper, Step 5 Preview or MiMo-V2.5-Pro?
Step 5 Preview costs $1.00 per million input tokens and $2.70 per million output tokens; MiMo-V2.5-Pro costs $0.4575 and $0.9152. Cost per solved task is known for MiMo-V2.5-Pro only.
Which has the bigger context window, Step 5 Preview or MiMo-V2.5-Pro?
MiMo-V2.5-Pro, with 1.05M tokens against 1.05M.
How many benchmarks is the Step 5 Preview vs MiMo-V2.5-Pro comparison based on?
40 benchmarks have a result for both models as of October 22, 2026. Step 5 Preview's coding index rests on 4 independent benchmarks and MiMo-V2.5-Pro's on 4. Where only one model has a result, the page says so instead of naming a winner.