Qwen3.5 Plus 2026-04-20 vs Step 3.7 Flash
Step 3.7 Flash costs 1.6x less per output token than Qwen3.5 Plus 2026-04-20 ($1.15 vs $1.80 per million). Updated October 22, 2026; 1 benchmarks have a result for both.
Qwen3.5 Plus 2026-04-20 or Step 3.7 Flash: which to pick
Only Qwen3.5 Plus 2026-04-20 has a coding score, 39.5 on the Vibe Coding Index; Step 3.7 Flash has none, so the two cannot be ranked on coding.
Pick Step 3.7 Flash for output tokens 1.6x cheaper ($1.15 vs $1.80 per million) and work measured by ALE-Bench, where it leads.
- Shared results
- 1
- Qwen3.5 Plus 2026-04-20 only
- 24
- Step 3.7 Flash only
- 17
- 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 Step 3.7 Flash has a AA Intelligence Index result, 19.5.
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 Step 3.7 Flash has a Design Arena: websites result, 1196.
Directional only
Long documents
Listed context window
Qwen3.5 Plus 2026-04-20
Qwen3.5 Plus 2026-04-20 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.7 Flash
Qwen3.5 Plus 2026-04-20 $0.0012, Step 3.7 Flash $0.0008 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, Step 3.7 Flash not benchmarked.
- Widest category
- Coding, 2.8 points apart on average over 1 shared benchmark.
- Widest single gap
- ALE-Bench: Qwen3.5 Plus 2026-04-20 608.9 against Step 3.7 Flash 694.1, 2.8 points apart on a 0 to 100 scale.
- Output price
- Qwen3.5 Plus 2026-04-20 $1.80 against Step 3.7 Flash $1.15 per million output tokens, 1.6x apart.
- Context window
- Qwen3.5 Plus 2026-04-20 takes 1M tokens, Step 3.7 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 | Qwen3.5 Plus 2026-04-20 | Bars | Step 3.7 Flash | Ties |
|---|---|---|---|---|
| Coding | 0 | 1 | ||
| All shared boards | 0 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index01
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | Leader |
|---|---|---|---|
| AA Coding Index | Not measured | 39.6 | Only Step 3.7 Flash 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 | 43.9% | Only Step 3.7 Flash measured |
| Terminal-Bench Hard (Artificial Analysis run) | Not measured | 35.6% | Only Step 3.7 Flash measured |
| ALE-Bench | 608.9 | 694.1 | Step 3.7 Flash |
| 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 | Step 3.7 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 19.5 | Only Step 3.7 Flash 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 | Step 3.7 Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | Not measured | 98.5% | Only Step 3.7 Flash measured |
| Vending-Bench 2 | $1 | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| Neither model has a result on the other 39 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | 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 | 80.9% | Only Step 3.7 Flash measured |
| Humanity's Last Exam (Artificial Analysis run) | Not measured | 21.4% | Only Step 3.7 Flash 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 |
| Neither model has a result on the other 15 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | 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 |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | 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 |
| Neither model has a result on the other 11 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | Not measured | 1196 | Only Step 3.7 Flash measured |
| Design Arena: UI components | Not measured | 1177 | Only Step 3.7 Flash measured |
| Design Arena: game dev | Not measured | 1158 | Only Step 3.7 Flash measured |
| Design Arena: data viz | Not measured | 1173 | Only Step 3.7 Flash measured |
| Design Arena: 3D | Not measured | 1129 | Only Step 3.7 Flash measured |
| Design Arena: all code categories | Not measured | 1182 | Only Step 3.7 Flash measured |
| Design Arena: SVG | Not measured | 1084 | Only Step 3.7 Flash measured |
| Design Arena: ASCII art | Not measured | 1152 | Only Step 3.7 Flash measured |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index7 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 Flash | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 30.4% | Not measured | Only Qwen3.5 Plus 2026-04-20 measured |
| IFBench | Not measured | 67.3% | Only Step 3.7 Flash measured |
| Long context reasoning (AA-LCR) | Not measured | 73.7% | Only Step 3.7 Flash 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 |
| Neither model has a result on the other 39 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-04-20 | Step 3.7 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 3.7 Flash costs less
Repository review
50K input + 3K output tokens
Step 3.7 Flash costs less
Agent loop
200K input + 10K output tokens
Step 3.7 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 Plus 2026-04-20 | StepFun Step 3.7 Flash |
|---|---|---|
| Maker | Qwen | StepFun |
| Weights | No public weights listed | Open weights |
| Released | April 27, 2026 | May 28, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $0.30 | $0.20 |
| Output $/Mtok | $1.80 | $1.15 |
| Coding index | 39.5 | Not benchmarked |
| Independent measurements behind it | 2 | 0 |
| Cost per solved task | $1.35 | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.5 Plus 2026-04-20 better than Step 3.7 Flash for coding?
Only Qwen3.5 Plus 2026-04-20 has a coding score, 39.5 on the Vibe Coding Index; Step 3.7 Flash has none, so the two cannot be ranked on coding. Pick Step 3.7 Flash for output tokens 1.6x cheaper ($1.15 vs $1.80 per million) and work measured by ALE-Bench, where it leads.
Which is cheaper, Qwen3.5 Plus 2026-04-20 or Step 3.7 Flash?
Qwen3.5 Plus 2026-04-20 costs $0.30 per million input tokens and $1.80 per million output tokens; Step 3.7 Flash costs $0.20 and $1.15. 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 Step 3.7 Flash?
Qwen3.5 Plus 2026-04-20, with 1M tokens against 262K.
How many benchmarks is the Qwen3.5 Plus 2026-04-20 vs Step 3.7 Flash 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 Step 3.7 Flash's on 0. Where only one model has a result, the page says so instead of naming a winner.