Qwen3.5 Plus 2026-02-15 vs Step 3.7 Flash
Step 3.7 Flash costs 1.4x less per output token than Qwen3.5 Plus 2026-02-15 ($1.15 vs $1.56 per million). Updated October 21, 2026; 8 benchmarks have a result for both.
Qwen3.5 Plus 2026-02-15 or Step 3.7 Flash: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Qwen3.5 Plus 2026-02-15 for a larger context window (1M against 262K tokens) and work measured by Design Arena: websites or Design Arena: UI components, where it leads.
- Shared results
- 8
- Qwen3.5 Plus 2026-02-15 only
- 0
- Step 3.7 Flash only
- 10
- 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
Neither has a coding score yet.
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
Web design
Design Arena: websites
Step 3.7 Flash
Step 3.7 Flash leads, 1196 against 1187.
Same board, both measured
Long documents
Listed context window
Qwen3.5 Plus 2026-02-15
Qwen3.5 Plus 2026-02-15 takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Step 3.7 Flash
Qwen3.5 Plus 2026-02-15 $0.0010, Step 3.7 Flash $0.0008 per turn.
List prices
At a glance
- Coding index
- Qwen3.5 Plus 2026-02-15 not benchmarked, Step 3.7 Flash not benchmarked.
- Widest category
- Web design, 3.2 points apart on average over 8 shared benchmarks.
- Widest single gap
- Design Arena: ASCII art: Qwen3.5 Plus 2026-02-15 1094 against Step 3.7 Flash 1152, 7.2 points apart on a 0 to 100 scale.
- Output price
- Qwen3.5 Plus 2026-02-15 $1.56 against Step 3.7 Flash $1.15 per million output tokens, 1.4x apart.
- Context window
- Qwen3.5 Plus 2026-02-15 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 2026-02-15 | Bars | Step 3.7 Flash | Ties |
|---|---|---|---|---|
| Web design | 1 | 7 | ||
| All shared boards | 1 | 7 |
CodingDirectional onlySix of these boards feed the Vibe Coding Index4 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| AA Coding Index | Not measured | 39.6 | Only Step 3.7 Flash 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 | Not measured | 694.1 | Only Step 3.7 Flash measured |
| Neither model has a result on the other 35 boards here | |||
IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | Not measured | 19.5 | Only Step 3.7 Flash measured |
| 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 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | Not measured | 98.5% | Only Step 3.7 Flash measured |
| Neither model has a result on the other 40 boards here | |||
ReasoningDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| 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 |
| Neither model has a result on the other 20 boards here | |||
MathNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| Neither model has a result on 13 boards here | |||
KnowledgeNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| Neither model has a result on 18 boards here | |||
Web designLike-for-likePublic boards, shown as published, kept out of the index17
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1187 | 1196 | Step 3.7 Flash |
| Design Arena: UI components | 1178 | 1179 | Step 3.7 Flash |
| Design Arena: game dev | 1105 | 1158 | Step 3.7 Flash |
| Design Arena: data viz | 1135 | 1172 | Step 3.7 Flash |
| Design Arena: 3D | 1119 | 1129 | Step 3.7 Flash |
| Design Arena: all code categories | 1167 | 1182 | Step 3.7 Flash |
| Design Arena: SVG | 1108 | 1085 | Qwen3.5 Plus 2026-02-15 |
| Design Arena: ASCII art | 1094 | 1152 | Step 3.7 Flash |
| Neither model has a result on the other 1 board here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | Step 3.7 Flash | Leader |
|---|---|---|---|
| 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 |
| Neither model has a result on the other 44 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Qwen3.5 Plus 2026-02-15 | 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 2026-02-15 | StepFun Step 3.7 Flash |
|---|---|---|
| Maker | Qwen | StepFun |
| Weights | No public weights listed | Open weights |
| Released | February 16, 2026 | May 28, 2026 |
| Context window | 1M | 262K |
| Input $/Mtok | $0.26 | $0.20 |
| Output $/Mtok | $1.56 | $1.15 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 0 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Qwen3.5 Plus 2026-02-15 better than Step 3.7 Flash for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Qwen3.5 Plus 2026-02-15 for a larger context window (1M against 262K tokens) and work measured by Design Arena: websites or Design Arena: UI components, where it leads.
Which is cheaper, Qwen3.5 Plus 2026-02-15 or Step 3.7 Flash?
Qwen3.5 Plus 2026-02-15 costs $0.26 per million input tokens and $1.56 per million output tokens; Step 3.7 Flash costs $0.20 and $1.15. Cost per solved task is known for neither of them.
Which has the bigger context window, Qwen3.5 Plus 2026-02-15 or Step 3.7 Flash?
Qwen3.5 Plus 2026-02-15, with 1M tokens against 262K.
How many benchmarks is the Qwen3.5 Plus 2026-02-15 vs Step 3.7 Flash comparison based on?
8 benchmarks have a result for both models as of October 21, 2026. Qwen3.5 Plus 2026-02-15's coding index rests on 0 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.