Qwen3.8 27B vs Step 3.5 Flash
Qwen3.8 27B leads Step 3.5 Flash on the Artificial Analysis Intelligence Index, 33.7 to 17.0, and Step 3.5 Flash costs 8.5x less per output token ($0.30 vs $2.55 per million). Updated October 21, 2026; 32 benchmarks have a result for both.
Qwen3.8 27B or Step 3.5 Flash: which to pick
Only Qwen3.8 27B has a coding score, 74.2 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 8.5x cheaper ($0.30 vs $2.55 per million).
- Shared results
- 32
- Qwen3.8 27B only
- 53
- Step 3.5 Flash only
- 3
- 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
No call
Only Qwen3.8 27B has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
Qwen3.8 27B
Qwen3.8 27B leads, 33.7 against 17.0.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Qwen3.8 27B has a AA Agentic Index result, 45.8.
Directional only
Reasoning
GPQA Diamond
No call
Only Qwen3.8 27B has a GPQA Diamond result, 88.9%.
Directional only
Knowledge
MMLU Pro
No call
Only Qwen3.8 27B has a MMLU Pro result, 84.3%.
Directional only
Long documents
Listed context window
Qwen3.8 27B
Qwen3.8 27B takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.5 Flash
Qwen3.8 27B $0.0017, Step 3.5 Flash $0.0003 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Qwen3.8 27B has the number, $1.26.
Directional only
At a glance
- Coding index
- Qwen3.8 27B 74.2 from 4 benchmarks, Step 3.5 Flash not benchmarked.
- Widest category
- Intelligence, 16.7 points apart on average over 1 shared benchmark.
- Widest single gap
- Long context reasoning (AA-LCR): Qwen3.8 27B 82.0% against Step 3.5 Flash 63.0%, 19.0 points apart on a 0 to 100 scale.
- Output price
- Qwen3.8 27B $2.55 against Step 3.5 Flash $0.30 per million output tokens, 8.5x apart.
- Context window
- Qwen3.8 27B takes 1M tokens, Step 3.5 Flash 262K.
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 | Qwen3.8 27B | Bars | Step 3.5 Flash | Ties |
|---|---|---|---|---|
| Coding | 2 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 5 | 0 | ||
| Math | 2 | 0 | ||
| Knowledge | 4 | 0 | ||
| General | 18 | 0 | ||
| All shared boards | 32 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index20
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LiveBench coding | 86.8% | Not measured | Only Qwen3.8 27B measured |
| LMArena WebDev | 1593 | Not measured | Only Qwen3.8 27B measured |
| AA Coding Index | 68.1 | Not measured | Only Qwen3.8 27B measured |
| LiveCodeBench (Vals AI) | 84.0% | Not measured | Only Qwen3.8 27B measured |
| SWE-bench Verified (Vals AI) | 86.0% | Not measured | Only Qwen3.8 27B measured |
| Vibe Code Bench (Vals AI) | 64.8% | Not measured | Only Qwen3.8 27B measured |
| Code migration (Vals AI) | 14.2% | Not measured | Only Qwen3.8 27B measured |
| ProgramBench (Vals AI) | 0.0% | Not measured | Only Qwen3.8 27B measured |
| IOI (Vals AI) | 39.1% | Not measured | Only Qwen3.8 27B measured |
| Terminal-Bench 2.1 (Vals AI) | 58.4% | Not measured | Only Qwen3.8 27B measured |
| SkillsBench (Vals AI) | 38.1% | Not measured | Only Qwen3.8 27B measured |
| CyberBench (Vals AI) | 67.8% | Not measured | Only Qwen3.8 27B measured |
| SciCode | 46.6% | Not measured | Only Qwen3.8 27B measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 32.6% | Only Step 3.5 Flash measured |
| LMArena Text: coding | 1483 | 1436 | Qwen3.8 27B |
| LMArena Text: software and IT | 1478 | 1434 | Qwen3.8 27B |
| LMArena WebDev: React | 1602 | Not measured | Only Qwen3.8 27B measured |
| LMArena WebDev: HTML | 1570 | Not measured | Only Qwen3.8 27B measured |
| LMArena WebDev: from an image | 1577 | Not measured | Only Qwen3.8 27B 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 | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 33.7 | 17.0 | Qwen3.8 27B |
| Epoch Capabilities Index | 151.7 | Not measured | Only Qwen3.8 27B measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| AA Agentic Index | 45.8 | Not measured | Only Qwen3.8 27B measured |
| LiveBench research | 59.4% | Not measured | Only Qwen3.8 27B measured |
| LiveBench browser | 32.0% | Not measured | Only Qwen3.8 27B measured |
| LiveBench long agentic | 27.9% | Not measured | Only Qwen3.8 27B measured |
| Finance Agent (Vals AI) | 48.5% | Not measured | Only Qwen3.8 27B measured |
| Tax Agent Bench (Vals AI) | 30.9% | Not measured | Only Qwen3.8 27B measured |
| Legal Research Bench (Vals AI) | 36.1% | Not measured | Only Qwen3.8 27B measured |
| Excel Modeling Benchmark (Vals AI) | 59.7% | Not measured | Only Qwen3.8 27B measured |
| Terminal-Bench-Science (Vals AI) | 0.0% | Not measured | Only Qwen3.8 27B measured |
| τ²-Bench Telecom | Not measured | 94.4% | Only Step 3.5 Flash measured |
| APEX-Agents | 47.5% | Not measured | Only Qwen3.8 27B measured |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 88.9% | Not measured | Only Qwen3.8 27B measured |
| LiveBench reasoning | 80.0% | Not measured | Only Qwen3.8 27B measured |
| MMMU Pro (Vals AI) | 83.9% | Not measured | Only Qwen3.8 27B measured |
| GPQA Diamond (Artificial Analysis run) | 90.5% | 83.1% | Qwen3.8 27B |
| Humanity's Last Exam (Artificial Analysis run) | 33.9% | 24.5% | Qwen3.8 27B |
| ARC-AGI | 87.5% | Not measured | Only Qwen3.8 27B measured |
| ARC-AGI-2 | 42.4% | Not measured | Only Qwen3.8 27B measured |
| LMArena Text: hard prompts | 1459 | 1411 | Qwen3.8 27B |
| LMArena Text: expert | 1479 | 1421 | Qwen3.8 27B |
| LMArena Text: hard prompts in English | 1461 | 1421 | Qwen3.8 27B |
| LMArena Vision: diagrams | 1285 | Not measured | Only Qwen3.8 27B measured |
| LMArena Vision: homework | 1295 | Not measured | Only Qwen3.8 27B measured |
| Neither model has a result on the other 10 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index20
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| ProofBench | 16.0% | Not measured | Only Qwen3.8 27B measured |
| LMArena Text: math | 1455 | 1408 | Qwen3.8 27B |
| LMArena Text: mathematical work | 1458 | 1421 | Qwen3.8 27B |
| Neither model has a result on the other 10 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index40
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| MMLU Pro | 84.3% | Not measured | Only Qwen3.8 27B measured |
| LegalBench (Vals AI) | 82.4% | Not measured | Only Qwen3.8 27B measured |
| TaxEval (Vals AI) | 70.8% | Not measured | Only Qwen3.8 27B measured |
| MortgageTax (Vals AI) | 64.9% | Not measured | Only Qwen3.8 27B measured |
| MedCode (Vals AI) | 28.7% | Not measured | Only Qwen3.8 27B measured |
| LMArena Text: science | 1467 | 1415 | Qwen3.8 27B |
| LMArena Text: medicine and healthcare | 1437 | 1408 | Qwen3.8 27B |
| LMArena Text: legal and government | 1447 | 1408 | Qwen3.8 27B |
| LMArena Text: business and finance | 1438 | 1394 | Qwen3.8 27B |
| Neither model has a result on the other 9 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LiveBench design | 75.9% | Not measured | Only Qwen3.8 27B measured |
| Neither model has a result on the other 8 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index180
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | Leader |
|---|---|---|---|
| LiveBench data analysis | 76.6% | Not measured | Only Qwen3.8 27B measured |
| SAGE (Vals AI) | 52.4% | Not measured | Only Qwen3.8 27B measured |
| MedScribe (Vals AI) | 83.8% | Not measured | Only Qwen3.8 27B measured |
| IFBench | Not measured | 66.5% | Only Step 3.5 Flash measured |
| Long context reasoning (AA-LCR) | 82.0% | 63.0% | Qwen3.8 27B |
| DTBench | 88.0% | Not measured | Only Qwen3.8 27B measured |
| LMCA | 41.4% | Not measured | Only Qwen3.8 27B measured |
| Surface Evolver Bench | 45.0% | Not measured | Only Qwen3.8 27B measured |
| LMArena Text | 1440 | 1403 | Qwen3.8 27B |
| LMArena Text: instruction following | 1436 | 1385 | Qwen3.8 27B |
| LMArena Text: creative writing | 1383 | 1357 | Qwen3.8 27B |
| LMArena Vision | 1269 | Not measured | Only Qwen3.8 27B measured |
| LMArena Text: English | 1448 | 1417 | Qwen3.8 27B |
| LMArena Text: non-English | 1428 | 1385 | Qwen3.8 27B |
| LMArena Text: Chinese | 1501 | 1446 | Qwen3.8 27B |
| LMArena Text: German | 1443 | 1405 | Qwen3.8 27B |
| LMArena Text: Japanese | 1387 | 1353 | Qwen3.8 27B |
| LMArena Text: Korean | 1384 | 1351 | Qwen3.8 27B |
| LMArena Text: French | 1465 | 1421 | Qwen3.8 27B |
| LMArena Text: Spanish | 1449 | 1419 | Qwen3.8 27B |
| LMArena Text: Russian | 1415 | 1385 | Qwen3.8 27B |
| LMArena Text: Polish | 1439 | 1389 | Qwen3.8 27B |
| LMArena Text: multi-turn | 1440 | 1404 | Qwen3.8 27B |
| LMArena Text: longer queries | 1448 | 1402 | Qwen3.8 27B |
| LMArena Text: writing and language | 1405 | 1372 | Qwen3.8 27B |
| LMArena Text: entertainment and media | 1393 | 1360 | Qwen3.8 27B |
| LMArena Vision: English | 1267 | Not measured | Only Qwen3.8 27B measured |
| LMArena Vision: Chinese | 1326 | Not measured | Only Qwen3.8 27B measured |
| LMArena Vision: reading text | 1281 | Not measured | Only Qwen3.8 27B measured |
| LMArena Vision: humor | 1235 | Not measured | Only Qwen3.8 27B measured |
| LMArena Vision: creative writing | 1237 | Not measured | Only Qwen3.8 27B measured |
| Neither model has a result on the other 15 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.8 27B | Step 3.5 Flash | 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 | Qwen3.8 27B | StepFun Step 3.5 Flash |
|---|---|---|
| Maker | Qwen | StepFun |
| Weights | Open weights | Open weights |
| Released | August 14, 2026 | January 29, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $0.425 | $0.10 |
| Output $/Mtok | $2.55 | $0.30 |
| Coding index | 74.2 | Not benchmarked |
| Independent measurements behind it | 4 | 0 |
| Cost per solved task | $1.26 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.8 27B better than Step 3.5 Flash for coding?
Only Qwen3.8 27B has a coding score, 74.2 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 8.5x cheaper ($0.30 vs $2.55 per million).
Which is cheaper, Qwen3.8 27B or Step 3.5 Flash?
Qwen3.8 27B costs $0.425 per million input tokens and $2.55 per million output tokens; Step 3.5 Flash costs $0.10 and $0.30. Cost per solved task is known for Qwen3.8 27B only.
Which has the bigger context window, Qwen3.8 27B or Step 3.5 Flash?
Qwen3.8 27B, with 1M tokens against 262K.
How many benchmarks is the Qwen3.8 27B vs Step 3.5 Flash comparison based on?
32 benchmarks have a result for both models as of October 21, 2026. Qwen3.8 27B's coding index rests on 4 independent benchmarks and Step 3.5 Flash's on 0. Where only one model has a result, the page says so instead of naming a winner.