Qwen3.5 Plus 2026-04-20 vs Solar Pro 4
Solar Pro 4 costs 3.0x less per output token than Qwen3.5 Plus 2026-04-20 ($0.60 vs $1.80 per million). Updated October 22, 2026; 1 benchmarks have a result for both.
Qwen3.5 Plus 2026-04-20 or Solar Pro 4: which to pick
Only Qwen3.5 Plus 2026-04-20 has a coding score, 39.5 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding.
Pick Solar Pro 4 for output tokens 3.0x cheaper ($0.60 vs $1.80 per million).
- Shared results
- 1
- Qwen3.5 Plus 2026-04-20 only
- 24
- Solar Pro 4 only
- 44
- Like-for-like categories
- 1 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 Qwen3.5 Plus 2026-04-20 has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Solar Pro 4 has a AA Intelligence Index result, 28.2.
Directional only
Reasoning
GPQA Diamond
No call
Only Qwen3.5 Plus 2026-04-20 has a GPQA Diamond result, 87.4%.
Directional only
Math
AIME
No call
Only Qwen3.5 Plus 2026-04-20 has a AIME result, 86.0%.
Directional only
Knowledge
MMLU Pro
No call
Only Qwen3.5 Plus 2026-04-20 has a MMLU Pro result, 87.2%.
Directional only
Web design
Design Arena: websites
No call
Only Solar Pro 4 has a Design Arena: websites result, 1176.
Directional only
Long documents
Listed context window
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 takes 1M tokens against 524K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Solar Pro 4
Qwen3.5 Plus 2026-04-20 $0.0012, Solar Pro 4 $0.0004 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Qwen3.5 Plus 2026-04-20 has the number, $1.35.
Directional only
At a glance
- Coding index
- Qwen3.5 Plus 2026-04-20 39.5 from 2 benchmarks, Solar Pro 4 not benchmarked.
- Widest category
- Coding, 14.3 points apart on average over 1 shared benchmark.
- Widest single gap
- ALE-Bench: Qwen3.5 Plus 2026-04-20 608.9 against Solar Pro 4 179.3, 14.3 points apart on a 0 to 100 scale.
- Output price
- Qwen3.5 Plus 2026-04-20 $1.80 against Solar Pro 4 $0.60 per million output tokens, 3.0x apart.
- Context window
- Qwen3.5 Plus 2026-04-20 takes 1M tokens, Solar Pro 4 524K.
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 Plus 2026-04-20 | Bars | Solar Pro 4 | Ties |
|---|---|---|---|---|
| Coding | 1 | 0 | ||
| All shared boards | 1 | 0 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index10
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1371 | Only Solar Pro 4 measured |
| AA Coding Index | Not measured | 52.7 | Only Solar Pro 4 measured |
| LiveCodeBench (Vals AI) | 85.3% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| SWE-bench Verified (Vals AI) | 71.2% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Vibe Code Bench (Vals AI) | 15.7% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| SciCode | Not measured | 48.0% | Only Solar Pro 4 measured |
| ALE-Bench | 608.9 | 179.3 | Qwen3.5 Plus 2026-04-20 |
| LMArena Text: coding | Not measured | 1438 | Only Solar Pro 4 measured |
| LMArena Text: software and IT | Not measured | 1431 | Only Solar Pro 4 measured |
| LMArena WebDev: React | Not measured | 1363 | Only Solar Pro 4 measured |
| LMArena WebDev: HTML | Not measured | 1371 | Only Solar Pro 4 measured |
| Neither model has a result on the other 32 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 28.2 | Only Solar Pro 4 measured |
| Epoch Capabilities Index | 146.2 | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | Not measured | 1105 | Only Solar Pro 4 measured |
| Vending-Bench 2 | $1 | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index10 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| GPQA Diamond | 87.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| MMMU Pro (Vals AI) | 22.8% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| GPQA Diamond (Artificial Analysis run) | Not measured | 89.1% | Only Solar Pro 4 measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 29.8% | Only Solar Pro 4 measured |
| GPQA Diamond (Epoch AI run) | 84.8% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Chess puzzles | 8.0% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Mystery game puzzles | 17.0% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LMArena Text: hard prompts | Not measured | 1400 | Only Solar Pro 4 measured |
| LMArena Text: expert | Not measured | 1428 | Only Solar Pro 4 measured |
| LMArena Text: hard prompts in English | Not measured | 1427 | Only Solar Pro 4 measured |
| Neither model has a result on the other 13 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index4 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| AIME | 86.0% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| OTIS Mock AIME | 86.7% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LMArena Text: math | Not measured | 1421 | Only Solar Pro 4 measured |
| LMArena Text: mathematical work | Not measured | 1427 | Only Solar Pro 4 measured |
| Neither model has a result on the other 10 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index11 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| MMLU Pro | 87.2% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LegalBench (Vals AI) | 85.1% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| CaseLaw (Vals AI) | 59.7% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| CorpFin (Vals AI) | 65.3% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| MortgageTax (Vals AI) | 60.8% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| MedQA (Vals AI) | 95.2% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| SimpleQA Verified | 25.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LMArena Text: science | Not measured | 1404 | Only Solar Pro 4 measured |
| LMArena Text: medicine and healthcare | Not measured | 1374 | Only Solar Pro 4 measured |
| LMArena Text: legal and government | Not measured | 1383 | Only Solar Pro 4 measured |
| LMArena Text: business and finance | Not measured | 1381 | Only Solar Pro 4 measured |
| Neither model has a result on the other 9 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1176 | Only Solar Pro 4 measured |
| Design Arena: UI components | Not measured | 1147 | Only Solar Pro 4 measured |
| Design Arena: game dev | Not measured | 1169 | Only Solar Pro 4 measured |
| Design Arena: data viz | Not measured | 1178 | Only Solar Pro 4 measured |
| Design Arena: 3D | Not measured | 1178 | Only Solar Pro 4 measured |
| Design Arena: all code categories | Not measured | 1182 | Only Solar Pro 4 measured |
| Neither model has a result on the other 3 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index23 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Solar Pro 4 | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 30.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Long context reasoning (AA-LCR) | Not measured | 70.7% | Only Solar Pro 4 measured |
| DTBench | 80.5% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LMCA | 36.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| CL-bench | 19.8% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| CL-bench Life | 12.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| LMArena Text | Not measured | 1388 | Only Solar Pro 4 measured |
| LMArena Text: instruction following | Not measured | 1375 | Only Solar Pro 4 measured |
| LMArena Text: creative writing | Not measured | 1317 | Only Solar Pro 4 measured |
| LMArena Text: English | Not measured | 1414 | Only Solar Pro 4 measured |
| LMArena Text: non-English | Not measured | 1363 | Only Solar Pro 4 measured |
| LMArena Text: Chinese | Not measured | 1422 | Only Solar Pro 4 measured |
| LMArena Text: German | Not measured | 1358 | Only Solar Pro 4 measured |
| LMArena Text: Japanese | Not measured | 1320 | Only Solar Pro 4 measured |
| LMArena Text: Korean | Not measured | 1383 | Only Solar Pro 4 measured |
| LMArena Text: French | Not measured | 1400 | Only Solar Pro 4 measured |
| LMArena Text: Spanish | Not measured | 1409 | Only Solar Pro 4 measured |
| LMArena Text: Russian | Not measured | 1357 | Only Solar Pro 4 measured |
| LMArena Text: Polish | Not measured | 1304 | Only Solar Pro 4 measured |
| LMArena Text: multi-turn | Not measured | 1385 | Only Solar Pro 4 measured |
| LMArena Text: longer queries | Not measured | 1382 | Only Solar Pro 4 measured |
| LMArena Text: writing and language | Not measured | 1344 | Only Solar Pro 4 measured |
| LMArena Text: entertainment and media | Not measured | 1332 | Only Solar Pro 4 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 Plus 2026-04-20 | Solar Pro 4 | 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
Solar Pro 4 costs less
Repository review
50K input + 3K output tokens
Solar Pro 4 costs less
Agent loop
200K input + 10K output tokens
Solar Pro 4 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 Plus 2026-04-20 | Upstage Solar Pro 4 |
|---|---|---|
| Maker | Qwen | Upstage |
| Weights | No public weights listed | No public weights listed |
| Released | April 27, 2026 | August 10, 2026 |
| Context window | 1M | 524K |
| Input $/Mtok | $0.30 | $0.15 |
| Output $/Mtok | $1.80 | $0.60 |
| Coding index | 39.5 | Not benchmarked |
| Independent measurements behind it | 2 | 1 |
| Cost per solved task | $1.35 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.5 Plus 2026-04-20 better than Solar Pro 4 for coding?
Only Qwen3.5 Plus 2026-04-20 has a coding score, 39.5 on the Vibe Coding Index; Solar Pro 4 has none, so the two cannot be ranked on coding. Pick Solar Pro 4 for output tokens 3.0x cheaper ($0.60 vs $1.80 per million).
Which is cheaper, Qwen3.5 Plus 2026-04-20 or Solar Pro 4?
Qwen3.5 Plus 2026-04-20 costs $0.30 per million input tokens and $1.80 per million output tokens; Solar Pro 4 costs $0.15 and $0.60. Cost per solved task is known for Qwen3.5 Plus 2026-04-20 only.
Which has the bigger context window, Qwen3.5 Plus 2026-04-20 or Solar Pro 4?
Qwen3.5 Plus 2026-04-20, with 1M tokens against 524K.
How many benchmarks is the Qwen3.5 Plus 2026-04-20 vs Solar Pro 4 comparison based on?
1 benchmarks have a result for both models as of October 22, 2026. Qwen3.5 Plus 2026-04-20's coding index rests on 2 independent benchmarks and Solar Pro 4's on 1. Where only one model has a result, the page says so instead of naming a winner.