Qwen3.5-Flash vs Qwen3.5 Plus 2026-04-20
Qwen3.5-Flash leads Qwen3.5 Plus 2026-04-20 on coding, 41.1 to 39.5 on the Vibe Coding Index, and Qwen3.5-Flash costs 6.9x less per output token ($0.26 vs $1.80 per million). Updated October 22, 2026; 20 benchmarks have a result for both.
Qwen3.5-Flash or Qwen3.5 Plus 2026-04-20: which to pick
Qwen3.5-Flash and Qwen3.5 Plus 2026-04-20 are level for coding, 41.1 against 39.5 on the Vibe Coding Index, so price and context decide.
Pick Qwen3.5 Plus 2026-04-20 for work measured by LiveCodeBench (Vals AI) or SWE-bench Verified (Vals AI), where it leads. Pick Qwen3.5-Flash for output tokens 6.9x cheaper ($0.26 vs $1.80 per million) and a lower cost per solved task ($0.40 against $1.35).
- Shared results
- 20
- Qwen3.5-Flash only
- 35
- Qwen3.5 Plus 2026-04-20 only
- 5
- 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
Level: 41.1 against 39.5, inside 2 points.
2 benchmarks behind each score
Reasoning
GPQA Diamond
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads, 87.4% against 82.8%.
Same board, both measured
Math
AIME
Qwen3.5-Flash
Qwen3.5-Flash leads, 92.5% against 86.0%.
Same board, both measured
Knowledge
MMLU Pro
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 leads, 87.2% against 84.1%.
Same board, both measured
Long documents
Listed context window
No call
Both take 1M tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5-Flash
Qwen3.5-Flash $0.0002, Qwen3.5 Plus 2026-04-20 $0.0012 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Qwen3.5-Flash
Qwen3.5-Flash $0.40, Qwen3.5 Plus 2026-04-20 $1.35.
Published attempt cost and pass rate
At a glance
- Coding index
- Qwen3.5-Flash 41.1 from 2 benchmarks, Qwen3.5 Plus 2026-04-20 39.5 from 2 benchmarks.
- Widest category
- Reasoning, 15.0 points apart on average over 5 shared benchmarks.
- Widest single gap
- MMMU Pro (Vals AI): Qwen3.5-Flash 81.9% against Qwen3.5 Plus 2026-04-20 22.8%, 59.1 points apart on a 0 to 100 scale.
- Output price
- Qwen3.5-Flash $0.26 against Qwen3.5 Plus 2026-04-20 $1.80 per million output tokens, 6.9x apart.
- Context window
- Both take 1M tokens.
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 | Qwen3.5-Flash | Bars | Qwen3.5 Plus 2026-04-20 | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 3 | 2 | ||
| Math | 1 | 1 | ||
| Knowledge | 1 | 5 | ||
| General | 2 | 1 | ||
| All shared boards | 7 | 13 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index03
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| LMArena WebDev | 1244 | Not measured | Only Qwen3.5-Flash measured |
| LiveCodeBench (Vals AI) | 83.3% | 85.3% | Qwen3.5 Plus 2026-04-20 |
| SWE-bench Verified (Vals AI) | 64.4% | 71.2% | Qwen3.5 Plus 2026-04-20 |
| Vibe Code Bench (Vals AI) | Not measured | 15.7% | Only Qwen3.5 Plus 2026-04-20 measured |
| ALE-Bench | 265.9 | 608.9 | Qwen3.5 Plus 2026-04-20 |
| LMArena Text: coding | 1412 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: software and IT | 1416 | Not measured | Only Qwen3.5-Flash measured |
| LMArena WebDev: React | 1229 | Not measured | Only Qwen3.5-Flash measured |
| LMArena WebDev: HTML | 1291 | Not measured | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 34 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Epoch Capabilities Index | 143.5 | 146.2 | Qwen3.5 Plus 2026-04-20 |
| Neither model has a result on the other 1 board here | |||
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Vending-Bench 2 | Not measured | $1 | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 41 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index32
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| GPQA Diamond | 82.8% | 87.4% | Qwen3.5 Plus 2026-04-20 |
| MMMU Pro (Vals AI) | 81.9% | 22.8% | Qwen3.5-Flash |
| GPQA Diamond (Epoch AI run) | 82.3% | 84.8% | Qwen3.5 Plus 2026-04-20 |
| Chess puzzles | 14.0% | 8.0% | Qwen3.5-Flash |
| Mystery game puzzles | 20.0% | 17.0% | Qwen3.5-Flash |
| LMArena Text: hard prompts | 1403 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: expert | 1407 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: hard prompts in English | 1409 | Not measured | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 15 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| AIME | 92.5% | 86.0% | Qwen3.5-Flash |
| OTIS Mock AIME | 84.4% | 86.7% | Qwen3.5 Plus 2026-04-20 |
| FrontierMath, tiers 1 to 3 | 18.2% | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: math | 1407 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: mathematical work | 1413 | Not measured | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 9 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index15
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| MMLU Pro | 84.1% | 87.2% | Qwen3.5 Plus 2026-04-20 |
| LegalBench (Vals AI) | 84.3% | 85.1% | Qwen3.5 Plus 2026-04-20 |
| CaseLaw (Vals AI) | 56.0% | 59.7% | Qwen3.5 Plus 2026-04-20 |
| CorpFin (Vals AI) | 63.6% | 65.3% | Qwen3.5 Plus 2026-04-20 |
| TaxEval (Vals AI) | 72.2% | Not measured | Only Qwen3.5-Flash measured |
| MortgageTax (Vals AI) | 67.4% | 60.8% | Qwen3.5-Flash |
| MedQA (Vals AI) | Not measured | 95.2% | Only Qwen3.5 Plus 2026-04-20 measured |
| MedCode (Vals AI) | 33.0% | Not measured | Only Qwen3.5-Flash measured |
| SimpleQA Verified | 20.3% | 25.4% | Qwen3.5 Plus 2026-04-20 |
| LMArena Text: science | 1415 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: medicine and healthcare | 1407 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: legal and government | 1398 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: business and finance | 1394 | Not measured | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 7 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| Neither model has a result on 9 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index21
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 42.5% | 30.4% | Qwen3.5-Flash |
| MedScribe (Vals AI) | 70.6% | Not measured | Only Qwen3.5-Flash measured |
| DTBench | 82.9% | 80.5% | Qwen3.5-Flash |
| LMCA | 29.1% | 36.4% | Qwen3.5 Plus 2026-04-20 |
| CL-bench | Not measured | 19.8% | Only Qwen3.5 Plus 2026-04-20 measured |
| CL-bench Life | Not measured | 12.4% | Only Qwen3.5 Plus 2026-04-20 measured |
| LMArena Text | 1397 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: instruction following | 1374 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: creative writing | 1343 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: English | 1404 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: non-English | 1385 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Chinese | 1445 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: German | 1390 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Japanese | 1369 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Korean | 1344 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: French | 1413 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Spanish | 1400 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Russian | 1380 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: Polish | 1376 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: multi-turn | 1393 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: longer queries | 1392 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: writing and language | 1369 | Not measured | Only Qwen3.5-Flash measured |
| LMArena Text: entertainment and media | 1347 | Not measured | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 25 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 | 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
Qwen3.5-Flash costs less
Repository review
50K input + 3K output tokens
Qwen3.5-Flash costs less
Agent loop
200K input + 10K output tokens
Qwen3.5-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 | Qwen3.5-Flash | Qwen3.5 Plus 2026-04-20 |
|---|---|---|
| Maker | Qwen | Qwen |
| Weights | No public weights listed | No public weights listed |
| Released | February 25, 2026 | April 27, 2026 |
| Context window | 1M | 1M |
| Input $/Mtok | $0.065 | $0.30 |
| Output $/Mtok | $0.26 | $1.80 |
| Coding index | 41.1 | 39.5 |
| Independent measurements behind it | 2 | 2 |
| Cost per solved task | $0.40 | $1.35 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.5-Flash better than Qwen3.5 Plus 2026-04-20 for coding?
Qwen3.5-Flash and Qwen3.5 Plus 2026-04-20 are level for coding, 41.1 against 39.5 on the Vibe Coding Index, so price and context decide. Pick Qwen3.5 Plus 2026-04-20 for work measured by LiveCodeBench (Vals AI) or SWE-bench Verified (Vals AI), where it leads. Pick Qwen3.5-Flash for output tokens 6.9x cheaper ($0.26 vs $1.80 per million) and a lower cost per solved task ($0.40 against $1.35).
Which is cheaper, Qwen3.5-Flash or Qwen3.5 Plus 2026-04-20?
Qwen3.5-Flash costs $0.065 per million input tokens and $0.26 per million output tokens; Qwen3.5 Plus 2026-04-20 costs $0.30 and $1.80. Per solved SWE-bench Verified task, Qwen3.5-Flash costs $0.40 and Qwen3.5 Plus 2026-04-20 $1.35.
Which has the bigger context window, Qwen3.5-Flash or Qwen3.5 Plus 2026-04-20?
Neither: both take 1M tokens.
How many benchmarks is the Qwen3.5-Flash vs Qwen3.5 Plus 2026-04-20 comparison based on?
20 benchmarks have a result for both models as of October 22, 2026. Qwen3.5-Flash's coding index rests on 2 independent benchmarks and Qwen3.5 Plus 2026-04-20's on 2. Where only one model has a result, the page says so instead of naming a winner.