Step 5 Preview vs Inkling 2 Small
Step 5 Preview leads Inkling 2 Small on coding, 57.4 to 48.9 on the Vibe Coding Index, and Inkling 2 Small costs 2.7x less per output token ($1.00 vs $2.70 per million). Updated November 14, 2026; 42 benchmarks have a result for both.
Step 5 Preview or Inkling 2 Small: which to pick
Pick Step 5 Preview for coding: it scores 57.4 on the Vibe Coding Index against 48.9 for Inkling 2 Small.
Pick Inkling 2 Small for output tokens 2.7x cheaper ($1.00 vs $2.70 per million) and a larger context window (1.05M against 1M tokens).
- Shared results
- 42
- Step 5 Preview only
- 33
- Inkling 2 Small only
- 9
- Like-for-like categories
- 6 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 57.4 against 48.9.
4 and 3 benchmarks behind the scores
Intelligence
AA Intelligence Index
Inkling 2 Small
Inkling 2 Small leads, 30.6 against 28.5.
Same board, both measured
General
Vals Index
Inkling 2 Small
Inkling 2 Small leads, 56.1% against 54.8%.
Same board, both measured
Long documents
Listed context window
Inkling 2 Small
Inkling 2 Small takes 1.05M tokens against 1M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Inkling 2 Small
Step 5 Preview $0.0024, Inkling 2 Small $0.0008 per turn.
List prices
At a glance
- Coding index
- Step 5 Preview 57.4 from 4 benchmarks, Inkling 2 Small 48.9 from 3 benchmarks.
- Widest category
- Coding, 10.0 points apart on average over 11 shared benchmarks.
- Widest single gap
- Terminal-Bench 4 (Vals AI): Step 5 Preview 31.8% against Inkling 2 Small 12.6%, 25.6 points apart on a 0 to 100 scale.
- Output price
- Step 5 Preview $2.70 against Inkling 2 Small $1.00 per million output tokens, 2.7x apart.
- Context window
- Step 5 Preview takes 1M tokens, Inkling 2 Small 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 | Inkling 2 Small | Ties |
|---|---|---|---|---|
| Coding | 5 | 6 | ||
| Intelligence | 0 | 1 | ||
| Agentic work | 0 | 6 | 1 tie | |
| Reasoning | 4 | 3 | ||
| Knowledge | 3 | 0 | ||
| General | 11 | 2 | ||
| All shared boards | 23 | 18 | 1 tie |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index56
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| LiveBench coding | 67.6% | Not measured | Only Step 5 Preview measured |
| LMArena WebDev | 1573 | 1647 | Inkling 2 Small |
| Terminal-Bench 4 (Vals AI) | 31.8% | 12.6% | Step 5 Preview |
| Vibe Code Bench (Vals AI) | 70.4% | 81.5% | Inkling 2 Small |
| Code migration (Vals AI) | 39.0% | Not measured | Only Step 5 Preview measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Inkling 2 Small measured |
| IOI (Vals AI) | 38.1% | Not measured | Only Step 5 Preview measured |
| SWE-bench Multimodal (Vals AI) | 40.8% | 43.1% | Inkling 2 Small |
| CyberBench (Vals AI) | Not measured | 72.7% | Only Inkling 2 Small measured |
| SciCode | 58.9% | 52.3% | Step 5 Preview |
| Terminal-Bench 4.0 (Artificial Analysis run) | 33.3% | 13.1% | Step 5 Preview |
| FrontierCode 2.0 | 12.0% | 25.4% | Inkling 2 Small |
| LMArena Text: coding | 1482 | 1455 | Step 5 Preview |
| LMArena Text: software and IT | 1471 | 1443 | Step 5 Preview |
| LMArena WebDev: React | 1589 | 1660 | Inkling 2 Small |
| LMArena WebDev: HTML | 1546 | 1661 | Inkling 2 Small |
| LMArena WebDev: from an image | 1551 | Not measured | Only Step 5 Preview measured |
| SWE-Bench Pro V2 | Not measured | 97.7% | Only Inkling 2 Small measured |
| GameBench 2 | 52.6 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 33 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| AA Intelligence Index | 28.5 | 30.6 | Inkling 2 Small |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index06
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| LiveBench research | 75.5% | Not measured | Only Step 5 Preview measured |
| LiveBench browser | 24.8% | Not measured | Only Step 5 Preview measured |
| LiveBench long agentic | 19.4% | Not measured | Only Step 5 Preview measured |
| SREBench (Vals AI) | 0.4% | 1.9% | Inkling 2 Small |
| Finance Agent (Vals AI) | 50.7% | Not measured | Only Step 5 Preview measured |
| Tax Agent Bench (Vals AI) | 27.3% | 38.9% | Inkling 2 Small |
| Legal Research Bench (Vals AI) | 40.4% | 46.6% | Inkling 2 Small |
| Harvey's Legal Agent Benchmark (Vals AI) | 12.9% | 21.7% | Inkling 2 Small |
| Excel Modeling Benchmark (Vals AI) | 57.1% | Not measured | Only Step 5 Preview measured |
| BioMysteryBench (Vals AI) | 67.4% | 70.0% | Inkling 2 Small |
| Terminal-Bench-Science (Vals AI) | 2.9% | 2.9% | Tie |
| Vals Science Index | 29.6% | 32.7% | Inkling 2 Small |
| APEX-Agents | Not measured | 46.8% | Only Inkling 2 Small measured |
| MCP Atlas | Not measured | 85.4% | Only Inkling 2 Small measured |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index43
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| LiveBench reasoning | 83.8% | Not measured | Only Step 5 Preview measured |
| MysteryMechanism (Vals AI) | 18.5% | 25.2% | Inkling 2 Small |
| Humanity's Last Exam (Artificial Analysis run) | 46.5% | 44.1% | Step 5 Preview |
| HLE-Diamond (Artificial Analysis run) | 24.3% | 28.7% | Inkling 2 Small |
| CritPt v2, hard subset (Artificial Analysis run) | 32.5% | 35.0% | Inkling 2 Small |
| ARC-AGI | Not measured | 96.5% | Only Inkling 2 Small measured |
| ARC-AGI-2 | Not measured | 81.7% | Only Inkling 2 Small measured |
| LMArena Text: hard prompts | 1463 | 1421 | Step 5 Preview |
| LMArena Text: expert | 1478 | 1478 | Step 5 Preview |
| LMArena Text: hard prompts in English | 1463 | 1424 | Step 5 Preview |
| LMArena Vision: diagrams | 1295 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: homework | 1274 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 14 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| ProofBench | 42.0% | Not measured | Only Step 5 Preview measured |
| LMArena Text: math | 1462 | Not measured | Only Step 5 Preview measured |
| LMArena Text: mathematical work | 1465 | Not measured | Only Step 5 Preview measured |
| MathArena | Not measured | 42.4% | Only Inkling 2 Small measured |
| Neither model has a result on the other 10 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| AA-Omniscience | 16.4 | 16.1 | Step 5 Preview |
| LMArena Text: science | 1462 | 1409 | Step 5 Preview |
| LMArena Text: medicine and healthcare | 1441 | Not measured | Only Step 5 Preview measured |
| LMArena Text: legal and government | 1441 | Not measured | Only Step 5 Preview measured |
| LMArena Text: business and finance | 1444 | 1415 | Step 5 Preview |
| Neither model has a result on the other 16 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| LiveBench design | 70.8% | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 8 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index112
| Benchmark | Step 5 Preview | Inkling 2 Small | Leader |
|---|---|---|---|
| Vals Index | 54.8% | 56.1% | Inkling 2 Small |
| 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 |
| SAGE (Vals AI) | Not measured | 88.6% | Only Inkling 2 Small measured |
| Long context reasoning (AA-LCR) | 88.3% | 83.3% | Step 5 Preview |
| GDPval-AA | 1591 | 1630 | Inkling 2 Small |
| LMArena Text | 1443 | 1403 | Step 5 Preview |
| LMArena Text: instruction following | 1445 | 1408 | Step 5 Preview |
| LMArena Text: creative writing | 1415 | 1348 | Step 5 Preview |
| LMArena Vision | 1263 | Not measured | Only Step 5 Preview measured |
| LMArena Text: English | 1455 | 1418 | Step 5 Preview |
| LMArena Text: non-English | 1429 | 1390 | Step 5 Preview |
| LMArena Text: Chinese | 1495 | Not measured | Only Step 5 Preview measured |
| LMArena Text: German | 1454 | Not measured | Only Step 5 Preview measured |
| LMArena Text: Japanese | 1397 | Not measured | Only Step 5 Preview measured |
| LMArena Text: Korean | 1404 | Not measured | Only Step 5 Preview measured |
| LMArena Text: French | 1446 | Not measured | Only Step 5 Preview measured |
| LMArena Text: Spanish | 1442 | Not measured | Only Step 5 Preview measured |
| LMArena Text: Russian | 1433 | 1377 | Step 5 Preview |
| LMArena Text: Polish | 1405 | Not measured | Only Step 5 Preview measured |
| LMArena Text: multi-turn | 1440 | 1408 | Step 5 Preview |
| LMArena Text: longer queries | 1453 | 1403 | Step 5 Preview |
| LMArena Text: writing and language | 1429 | 1381 | Step 5 Preview |
| LMArena Text: entertainment and media | 1413 | 1359 | Step 5 Preview |
| LMArena Vision: English | 1279 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: Chinese | 1315 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: reading text | 1278 | Not measured | Only Step 5 Preview measured |
| LMArena Vision: creative writing | 1251 | Not measured | Only Step 5 Preview measured |
| Neither model has a result on the other 21 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Step 5 Preview | Inkling 2 Small | 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
Inkling 2 Small costs less
Repository review
50K input + 3K output tokens
Inkling 2 Small costs less
Agent loop
200K input + 10K output tokens
Inkling 2 Small 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 | Thinking Machines Inkling 2 Small |
|---|---|---|
| Maker | StepFun | Thinking Machines |
| Weights | Open weights | Open weights |
| Released | October 8, 2026 | November 9, 2026 |
| Context window | 1M | 1.05M |
| Input $/Mtok | $1.00 | $0.30 |
| Output $/Mtok | $2.70 | $1.00 |
| Coding index | 57.4 | 48.9 |
| Independent measurements behind it | 4 | 3 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Step 5 Preview better than Inkling 2 Small for coding?
Pick Step 5 Preview for coding: it scores 57.4 on the Vibe Coding Index against 48.9 for Inkling 2 Small. Pick Inkling 2 Small for output tokens 2.7x cheaper ($1.00 vs $2.70 per million) and a larger context window (1.05M against 1M tokens).
Which is cheaper, Step 5 Preview or Inkling 2 Small?
Step 5 Preview costs $1.00 per million input tokens and $2.70 per million output tokens; Inkling 2 Small costs $0.30 and $1.00. Cost per solved task is known for neither of them.
Which has the bigger context window, Step 5 Preview or Inkling 2 Small?
Inkling 2 Small, with 1.05M tokens against 1M.
How many benchmarks is the Step 5 Preview vs Inkling 2 Small comparison based on?
42 benchmarks have a result for both models as of November 14, 2026. Step 5 Preview's coding index rests on 4 independent benchmarks and Inkling 2 Small's on 3. Where only one model has a result, the page says so instead of naming a winner.