Qwen3.5-27B vs Qwen3.8 Flash
Updated October 21, 2026. 0 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Qwen3.5-27B scores 22.6 and Qwen3.8 Flash 87.4 on the Vibe Coding Index, but no coding benchmark measured both, so the gap is directional, not a ranking.
Pick Qwen3.8 Flash when output tokens cost 4.6x less, or when the context window is larger, 1M against 262K tokens.
- Shared results
- 0
- Qwen3.5-27B only
- 53
- Qwen3.8 Flash only
- 7
- Like-for-like categories
- 0 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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, four public coding benchmarks
No call
22.6 against 87.4, from different benchmarks with none in common.
Directional only
Intelligence
AA Intelligence Index
No call
Only Qwen3.5-27B has a AA Intelligence Index result, 22.9.
Directional only
Long documents
Listed context window
Qwen3.8 Flash
Qwen3.8 Flash takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.8 Flash
Qwen3.5-27B $0.0014, Qwen3.8 Flash $0.0004 per turn.
List prices
At a glance
- Coding index
- Qwen3.5-27B 22.6 from 1 benchmark, Qwen3.8 Flash 87.4 from 1 benchmark.
- Widest category
- No category has a result for both models.
- Widest single gap
- No benchmark has a result for both models.
- Output price
- Qwen3.5-27B $2.16 against Qwen3.8 Flash $0.47 per million output tokens, 4.6x apart.
- Context window
- Qwen3.5-27B takes 262K tokens, Qwen3.8 Flash 1M.
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.
CodingDirectional onlyFour of these boards feed the Vibe Coding Index9 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LiveBench coding | Not measured | 87.4% | Only Qwen3.8 Flash measured |
| LMArena WebDev | 1358 | Not measured | Only Qwen3.5-27B measured |
| Terminal-Bench Hard (Artificial Analysis run) | 32.6% | Not measured | Only Qwen3.5-27B measured |
| WeirdML | 39.5% | Not measured | Only Qwen3.5-27B measured |
| ALE-Bench | 349.4 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: coding | 1427 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: software and IT | 1431 | Not measured | Only Qwen3.5-27B measured |
| LMArena WebDev: React | 1346 | Not measured | Only Qwen3.5-27B measured |
| LMArena WebDev: HTML | 1386 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 29 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 22.9 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index5 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LiveBench research | Not measured | 74.6% | Only Qwen3.8 Flash measured |
| LiveBench browser | Not measured | 48.0% | Only Qwen3.8 Flash measured |
| LiveBench long agentic | Not measured | 37.1% | Only Qwen3.8 Flash measured |
| τ²-Bench Telecom | 93.9% | Not measured | Only Qwen3.5-27B measured |
| Vending-Bench 2 | $202 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 34 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LiveBench reasoning | Not measured | 87.4% | Only Qwen3.8 Flash measured |
| GPQA Diamond (Artificial Analysis run) | 85.8% | Not measured | Only Qwen3.5-27B measured |
| Humanity's Last Exam (Artificial Analysis run) | 23.9% | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: hard prompts | 1415 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: expert | 1427 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: hard prompts in English | 1429 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: diagrams | 1249 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: homework | 1256 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 13 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LMArena Text: math | 1429 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: mathematical work | 1429 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LMArena Text: science | 1437 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: medicine and healthcare | 1425 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: legal and government | 1405 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: business and finance | 1399 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 13 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LiveBench design | Not measured | 72.8% | Only Qwen3.8 Flash measured |
| Neither model has a result on the other 8 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index30 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 Flash | Leader |
|---|---|---|---|
| LiveBench data analysis | Not measured | 74.2% | Only Qwen3.8 Flash measured |
| IFBench | 75.6% | Not measured | Only Qwen3.5-27B measured |
| Long context reasoning (AA-LCR) | 77.7% | Not measured | Only Qwen3.5-27B measured |
| DTBench | 82.4% | Not measured | Only Qwen3.5-27B measured |
| LMCA | 34.0% | Not measured | Only Qwen3.5-27B measured |
| LMArena Text | 1409 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: instruction following | 1393 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: creative writing | 1362 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision | 1241 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: English | 1425 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: non-English | 1390 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Chinese | 1478 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: German | 1392 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Japanese | 1346 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Korean | 1359 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: French | 1410 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Spanish | 1407 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Russian | 1390 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: Polish | 1375 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: multi-turn | 1410 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: longer queries | 1413 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: writing and language | 1380 | Not measured | Only Qwen3.5-27B measured |
| LMArena Text: entertainment and media | 1363 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: English | 1246 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: Chinese | 1301 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: reading text | 1246 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: humor | 1227 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: captioning | 1170 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: recognizing things | 1210 | Not measured | Only Qwen3.5-27B measured |
| LMArena Vision: creative writing | 1224 | Not measured | Only Qwen3.5-27B measured |
| Neither model has a result on the other 16 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5-27B | Qwen3.8 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
Qwen3.8 Flash costs less
Repository review
50K input + 3K output tokens
Qwen3.8 Flash costs less
Agent loop
200K input + 10K output tokens
Qwen3.8 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 | Qwen3.5-27B | Qwen3.8 Flash |
|---|---|---|
| Maker | Qwen | Qwen |
| Weights | Open weights | Open weights |
| Released | February 25, 2026 | August 26, 2026 |
| Context window | 262K | 1M |
| Input $/Mtok | $0.27 | $0.15 |
| Output $/Mtok | $2.16 | $0.47 |
| Coding index | 22.6 | 87.4 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.5-27B better than Qwen3.8 Flash for coding?
Qwen3.5-27B scores 22.6 and Qwen3.8 Flash 87.4 on the Vibe Coding Index, but no coding benchmark measured both, so the gap is directional, not a ranking. Pick Qwen3.8 Flash when output tokens cost 4.6x less, or when the context window is larger, 1M against 262K tokens.
Which is cheaper, Qwen3.5-27B or Qwen3.8 Flash?
Qwen3.5-27B costs $0.27 per million input tokens and $2.16 per million output tokens; Qwen3.8 Flash costs $0.15 and $0.47. Cost per solved task is known for neither of them.
Which has the bigger context window, Qwen3.5-27B or Qwen3.8 Flash?
Qwen3.8 Flash, with 1M tokens against 262K.
How many benchmarks is the Qwen3.5-27B vs Qwen3.8 Flash comparison based on?
0 benchmarks have a result for both models as of October 21, 2026. Qwen3.5-27B's coding index rests on 1 independent benchmark and Qwen3.8 Flash's on 1. Where only one model has a result, the page says so instead of naming a winner.