Step 3.5 Flash vs Inkling 2 Small
Step 3.5 Flash costs 3.3x less per output token than Inkling 2 Small ($0.30 vs $1.00 per million). Updated November 14, 2026; 20 benchmarks have a result for both.
Step 3.5 Flash or Inkling 2 Small: which to pick
Only Inkling 2 Small has a coding score, 48.9 on the Vibe Coding Index; Step 3.5 Flash has none, so the two cannot be ranked on coding.
Pick Step 3.5 Flash for output tokens 3.3x cheaper ($0.30 vs $1.00 per million) and work measured by LMArena Text: science or LMArena Text: creative writing, where it leads.
- Shared results
- 20
- Step 3.5 Flash only
- 15
- Inkling 2 Small only
- 31
- Like-for-like categories
- 5 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
No call
Only Inkling 2 Small has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Inkling 2 Small has a AA Intelligence Index result, 30.6.
Directional only
General
Vals Index
No call
Only Inkling 2 Small has a Vals Index result, 56.1%.
Directional only
Long documents
Listed context window
Inkling 2 Small
Inkling 2 Small takes 1.05M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.5 Flash
Step 3.5 Flash $0.0003, Inkling 2 Small $0.0008 per turn.
List prices
At a glance
- Coding index
- Step 3.5 Flash not benchmarked, Inkling 2 Small 48.9 from 3 benchmarks.
- Widest category
- Math, 23.8 points apart on average over 1 shared benchmark.
- Widest single gap
- MathArena: Step 3.5 Flash 18.7% against Inkling 2 Small 42.4%, 23.8 points apart on a 0 to 100 scale.
- Output price
- Step 3.5 Flash $0.30 against Inkling 2 Small $1.00 per million output tokens, 3.3x apart.
- Context window
- Step 3.5 Flash takes 262K 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 3.5 Flash | Bars | Inkling 2 Small | Ties |
|---|---|---|---|---|
| Coding | 0 | 2 | ||
| Reasoning | 0 | 4 | ||
| Math | 0 | 1 | ||
| Knowledge | 1 | 1 | ||
| General | 2 | 9 | ||
| All shared boards | 3 | 17 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index02
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1647 | Only Inkling 2 Small measured |
| Terminal-Bench 4 (Vals AI) | Not measured | 12.6% | Only Inkling 2 Small measured |
| Vibe Code Bench (Vals AI) | Not measured | 81.5% | Only Inkling 2 Small measured |
| ProgramBench (Vals AI) | Not measured | 0.5% | Only Inkling 2 Small measured |
| SWE-bench Multimodal (Vals AI) | Not measured | 43.1% | Only Inkling 2 Small measured |
| CyberBench (Vals AI) | Not measured | 72.7% | Only Inkling 2 Small measured |
| SciCode | Not measured | 52.3% | Only Inkling 2 Small measured |
| Terminal-Bench Hard (Artificial Analysis run) | 32.6% | Not measured | Only Step 3.5 Flash measured |
| Terminal-Bench 4.0 (Artificial Analysis run) | Not measured | 13.1% | Only Inkling 2 Small measured |
| FrontierCode 2.0 | Not measured | 25.4% | Only Inkling 2 Small measured |
| LMArena Text: coding | 1435 | 1455 | Inkling 2 Small |
| LMArena Text: software and IT | 1434 | 1443 | Inkling 2 Small |
| LMArena WebDev: React | Not measured | 1660 | Only Inkling 2 Small measured |
| LMArena WebDev: HTML | Not measured | 1661 | Only Inkling 2 Small measured |
| SWE-Bench Pro V2 | Not measured | 97.7% | Only Inkling 2 Small measured |
| Neither model has a result on the other 37 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 30.6 | Only Inkling 2 Small measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| SREBench (Vals AI) | Not measured | 1.9% | Only Inkling 2 Small measured |
| Tax Agent Bench (Vals AI) | Not measured | 38.9% | Only Inkling 2 Small measured |
| Legal Research Bench (Vals AI) | Not measured | 46.6% | Only Inkling 2 Small measured |
| Harvey's Legal Agent Benchmark (Vals AI) | Not measured | 21.7% | Only Inkling 2 Small measured |
| BioMysteryBench (Vals AI) | Not measured | 70.0% | Only Inkling 2 Small measured |
| Terminal-Bench-Science (Vals AI) | Not measured | 2.9% | Only Inkling 2 Small measured |
| Vals Science Index | Not measured | 32.7% | Only Inkling 2 Small measured |
| τ²-Bench Telecom | 94.4% | Not measured | Only Step 3.5 Flash measured |
| 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 34 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| MysteryMechanism (Vals AI) | Not measured | 25.2% | Only Inkling 2 Small measured |
| GPQA Diamond (Artificial Analysis run) | 83.1% | Not measured | Only Step 3.5 Flash measured |
| Humanity's Last Exam (Artificial Analysis run) | 24.5% | 44.1% | Inkling 2 Small |
| HLE-Diamond (Artificial Analysis run) | Not measured | 28.7% | Only Inkling 2 Small measured |
| CritPt v2, hard subset (Artificial Analysis run) | Not measured | 35.0% | Only Inkling 2 Small measured |
| 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 | 1410 | 1421 | Inkling 2 Small |
| LMArena Text: expert | 1421 | 1478 | Inkling 2 Small |
| LMArena Text: hard prompts in English | 1420 | 1424 | Inkling 2 Small |
| Neither model has a result on the other 16 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| LMArena Text: math | 1406 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: mathematical work | 1419 | Not measured | Only Step 3.5 Flash measured |
| MathArena | 18.7% | 42.4% | Inkling 2 Small |
| Neither model has a result on the other 11 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| AA-Omniscience | Not measured | 16.1 | Only Inkling 2 Small measured |
| LMArena Text: science | 1414 | 1409 | Step 3.5 Flash |
| LMArena Text: medicine and healthcare | 1408 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: legal and government | 1407 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: business and finance | 1394 | 1415 | Inkling 2 Small |
| Neither model has a result on the other 16 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| Neither model has a result on 9 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index29
| Benchmark | Step 3.5 Flash | Inkling 2 Small | Leader |
|---|---|---|---|
| Vals Index | Not measured | 56.1% | Only Inkling 2 Small measured |
| SAGE (Vals AI) | Not measured | 88.6% | Only Inkling 2 Small measured |
| IFBench | 66.5% | Not measured | Only Step 3.5 Flash measured |
| Long context reasoning (AA-LCR) | 63.0% | 83.3% | Inkling 2 Small |
| GDPval-AA | Not measured | 1630 | Only Inkling 2 Small measured |
| LMArena Text | 1402 | 1403 | Inkling 2 Small |
| LMArena Text: instruction following | 1385 | 1408 | Inkling 2 Small |
| LMArena Text: creative writing | 1357 | 1348 | Step 3.5 Flash |
| LMArena Text: English | 1417 | 1418 | Inkling 2 Small |
| LMArena Text: non-English | 1385 | 1390 | Inkling 2 Small |
| LMArena Text: Chinese | 1446 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: German | 1403 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Japanese | 1353 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Korean | 1350 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: French | 1421 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Spanish | 1418 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: Russian | 1385 | 1377 | Step 3.5 Flash |
| LMArena Text: Polish | 1388 | Not measured | Only Step 3.5 Flash measured |
| LMArena Text: multi-turn | 1404 | 1408 | Inkling 2 Small |
| LMArena Text: longer queries | 1402 | 1403 | Inkling 2 Small |
| LMArena Text: writing and language | 1371 | 1381 | Inkling 2 Small |
| LMArena Text: entertainment and media | 1359 | 1359 | Inkling 2 Small |
| Neither model has a result on the other 27 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Step 3.5 Flash | 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
Step 3.5 Flash costs less
Repository review
50K input + 3K output tokens
Step 3.5 Flash costs less
Agent loop
200K input + 10K output tokens
Step 3.5 Flash 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 3.5 Flash | Thinking Machines Inkling 2 Small |
|---|---|---|
| Maker | StepFun | Thinking Machines |
| Weights | Open weights | Open weights |
| Released | January 29, 2026 | November 9, 2026 |
| Context window | 262K | 1.05M |
| Input $/Mtok | $0.10 | $0.30 |
| Output $/Mtok | $0.30 | $1.00 |
| Coding index | Not benchmarked | 48.9 |
| Independent measurements behind it | 0 | 3 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Step 3.5 Flash better than Inkling 2 Small for coding?
Only Inkling 2 Small has a coding score, 48.9 on the Vibe Coding Index; Step 3.5 Flash has none, so the two cannot be ranked on coding. Pick Step 3.5 Flash for output tokens 3.3x cheaper ($0.30 vs $1.00 per million) and work measured by LMArena Text: science or LMArena Text: creative writing, where it leads.
Which is cheaper, Step 3.5 Flash or Inkling 2 Small?
Step 3.5 Flash costs $0.10 per million input tokens and $0.30 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 3.5 Flash or Inkling 2 Small?
Inkling 2 Small, with 1.05M tokens against 262K.
How many benchmarks is the Step 3.5 Flash vs Inkling 2 Small comparison based on?
20 benchmarks have a result for both models as of November 14, 2026. Step 3.5 Flash's coding index rests on 0 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.