Model comparison
Qwen1.5 4b Chat vs Qwen3.5-Flash
Qwen3.5-Flash is the stronger model overall, scoring 42.3 to 28.3 on the Noometry Index.
Last verified . 13 shared benchmarks.
Alibaba (Qwen)Summary
- They share 13 benchmarks with published results for both. Qwen1.5 4b Chat scores higher in 0 categories and Qwen3.5-Flash in 8 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Qwen3.5-Flash leads 58.2 to 23.9.
- Qwen1.5 4b Chat has downloadable open weights; the other is API-only.
Side by side
| Qwen1.5 4b Chat | Qwen3.5-Flash | |
|---|---|---|
| Provider | Alibaba (Qwen) | Alibaba (Qwen) |
| Noometry Index | 28.3 | 42.3 |
| Released | — | 2026-02-23 |
| Weights | Open | Proprietary |
| Context window | — | 1M |
| Max output | — | 66K |
| Input $ / M tokens | — | $0.10 |
| Output $ / M tokens | — | $0.40 |
| Results tracked | 13 | 32 |
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Category by category
Coding Qwen3.5-Flash leads
Qwen1.5 4b Chat: 28.6 (#305), Qwen3.5-Flash: 33.9 (#234)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Coding | 999 | 1412 |
| LMArena WebDev | — | 1243 |
| ALE-Bench | — | 221.8 |
Agentic & Tool Use Not comparable
Qwen1.5 4b Chat: —, Qwen3.5-Flash: —
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| Vending-Bench 2 | — | 462.69 |
Reasoning Qwen3.5-Flash leads
Qwen1.5 4b Chat: 17.7 (#277), Qwen3.5-Flash: 32.9 (#63)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Hard Prompts | 976 | 1404 |
| Chess Puzzles | — | 21% |
| Mystery Game Puzzles | — | 20% |
| DTBench | — | 82.9% |
| LMCA | — | 29.1% |
| Epoch Capabilities Index | — | 143.98 |
Math Qwen3.5-Flash leads
Qwen1.5 4b Chat: 27.9 (#233), Qwen3.5-Flash: 36.3 (#117)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Math | 1026 | 1407 |
| FrontierMath (Tiers 1-3) | — | 18.2% |
| OTIS Mock AIME 2024-2025 | — | 84.4% |
| FrontierMath (Feb 2025 set) | — | 6.2% |
| FrontierMath Tier 4 (v1) | — | 0% |
Knowledge Qwen3.5-Flash leads
Qwen1.5 4b Chat: 26.2 (#252), Qwen3.5-Flash: 43.2 (#84)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Expert | 980 | 1408 |
| GPQA Diamond | — | 82.3% |
| SimpleQA Verified | — | 20.3% |
| Vectara Hallucination Rate | — | 10.5% |
Multilingual Qwen3.5-Flash leads
Qwen1.5 4b Chat: 24.2 (#285), Qwen3.5-Flash: 50.7 (#116)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Non-English | 979 | 1385 |
| LMArena Chinese | 1024 | 1446 |
| LMArena German | 902 | 1389 |
| LMArena Russian | 952 | 1379 |
| LMArena French | — | 1412 |
| LMArena Japanese | — | 1369 |
| LMArena Korean | — | 1344 |
| LMArena Spanish | — | 1399 |
Instruction Following Qwen3.5-Flash leads
Qwen1.5 4b Chat: 49.3 (#295), Qwen3.5-Flash: 72.8 (#133)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Instruction Following | 979 | 1374 |
Long Context Qwen3.5-Flash leads
Qwen1.5 4b Chat: 30.1 (#285), Qwen3.5-Flash: 42.4 (#119)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Longer Query | 988 | 1392 |
Writing & Preference Qwen3.5-Flash leads
Qwen1.5 4b Chat: 23.9 (#304), Qwen3.5-Flash: 58.2 (#117)
| Benchmark | Qwen1.5 4b Chat | Qwen3.5-Flash |
|---|---|---|
| LMArena Text | 997 | 1397 |
| LMArena Creative Writing | 969 | 1343 |
| LMArena Multi-Turn | 977 | 1393 |
Frequently asked questions
Is Qwen1.5 4b Chat better than Qwen3.5-Flash?
Qwen3.5-Flash is the stronger model overall, scoring 42.3 to 28.3 on the Noometry Index.
Is Qwen1.5 4b Chat or Qwen3.5-Flash better for coding?
Qwen3.5-Flash scores higher on coding benchmarks: 33.9 versus 28.6 in the Noometry coding category.
How many benchmarks do Qwen1.5 4b Chat and Qwen3.5-Flash share?
13 benchmarks have published results for both models. Qwen1.5 4b Chat has 13 scored results on Noometry and Qwen3.5-Flash has 32.