Phi 4 vs Qwen3.5-Flash
Phi 4 costs 1.9x less per output token than Qwen3.5-Flash ($0.14 vs $0.26 per million). Updated October 21, 2026; 30 benchmarks have a result for both.
Phi 4 or Qwen3.5-Flash: which to pick
Only Qwen3.5-Flash has a coding score, 41.1 on the Vibe Coding Index; Phi 4 has none, so the two cannot be ranked on coding.
Pick Phi 4 for output tokens 1.9x cheaper ($0.14 vs $0.26 per million).
- Shared results
- 30
- Phi 4 only
- 15
- Qwen3.5-Flash only
- 25
- 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
Only Qwen3.5-Flash has a coding score, so no call is made.
One side not measured
Intelligence
AA Intelligence Index
No call
Only Phi 4 has a AA Intelligence Index result, 5.9.
Directional only
Reasoning
GPQA Diamond
No call
Only Qwen3.5-Flash has a GPQA Diamond result, 82.8%.
Directional only
Math
AIME
No call
Only Qwen3.5-Flash has a AIME result, 92.5%.
Directional only
Knowledge
MMLU Pro
No call
Only Qwen3.5-Flash has a MMLU Pro result, 84.1%.
Directional only
Long documents
Listed context window
Qwen3.5-Flash
Qwen3.5-Flash takes 1M tokens against 16K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Phi 4
Phi 4 $0.0001, Qwen3.5-Flash $0.0002 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only Qwen3.5-Flash has the number, $0.40.
Directional only
At a glance
- Coding index
- Phi 4 not benchmarked, Qwen3.5-Flash 41.1 from 2 benchmarks.
- Widest category
- Math, 41.4 points apart on average over 3 shared benchmarks.
- Widest single gap
- OTIS Mock AIME: Phi 4 13.8% against Qwen3.5-Flash 84.4%, 70.7 points apart on a 0 to 100 scale.
- Output price
- Phi 4 $0.14 against Qwen3.5-Flash $0.26 per million output tokens, 1.9x apart.
- Context window
- Phi 4 takes 16K tokens, Qwen3.5-Flash 1M.
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 | Phi 4 | Bars | Qwen3.5-Flash | Ties |
|---|---|---|---|---|
| Coding | 0 | 2 | ||
| Intelligence | 0 | 1 | ||
| Reasoning | 0 | 4 | ||
| Math | 0 | 3 | ||
| Knowledge | 0 | 4 | ||
| General | 0 | 16 | ||
| All shared boards | 0 | 30 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index02
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| LMArena WebDev | Not measured | 1244 | Only Qwen3.5-Flash measured |
| LiveCodeBench (Vals AI) | Not measured | 83.3% | Only Qwen3.5-Flash measured |
| SWE-bench Verified (Vals AI) | Not measured | 64.4% | Only Qwen3.5-Flash measured |
| LiveCodeBench (Artificial Analysis run) | 23.1% | Not measured | Only Phi 4 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 3.8% | Not measured | Only Phi 4 measured |
| ALE-Bench | Not measured | 265.9 | Only Qwen3.5-Flash measured |
| LMArena Text: coding | 1231 | 1412 | Qwen3.5-Flash |
| LMArena Text: software and IT | 1228 | 1416 | Qwen3.5-Flash |
| LMArena WebDev: React | Not measured | 1229 | Only Qwen3.5-Flash measured |
| LMArena WebDev: HTML | Not measured | 1291 | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 28 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 5.9 | Not measured | Only Phi 4 measured |
| Epoch Capabilities Index | 130.5 | 143.5 | Qwen3.5-Flash |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 0.0% | Not measured | Only Phi 4 measured |
| BALROG | 11.6% | Not measured | Only Phi 4 measured |
| Neither model has a result on the other 37 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| GPQA Diamond | Not measured | 82.8% | Only Qwen3.5-Flash measured |
| MMMU Pro (Vals AI) | Not measured | 81.9% | Only Qwen3.5-Flash measured |
| GPQA Diamond (Artificial Analysis run) | 57.5% | Not measured | Only Phi 4 measured |
| Humanity's Last Exam (Artificial Analysis run) | 3.8% | Not measured | Only Phi 4 measured |
| GPQA Diamond (Epoch AI run) | 56.1% | 82.3% | Qwen3.5-Flash |
| Chess puzzles | Not measured | 14.0% | Only Qwen3.5-Flash measured |
| Mystery game puzzles | Not measured | 20.0% | Only Qwen3.5-Flash measured |
| LMArena Text: hard prompts | 1220 | 1403 | Qwen3.5-Flash |
| LMArena Text: expert | 1203 | 1407 | Qwen3.5-Flash |
| LMArena Text: hard prompts in English | 1230 | 1409 | Qwen3.5-Flash |
| Neither model has a result on the other 11 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index03
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AIME | Not measured | 92.5% | Only Qwen3.5-Flash measured |
| AA Math Index | 18.0 | Not measured | Only Phi 4 measured |
| AIME 2025 (Artificial Analysis run) | 18.0% | Not measured | Only Phi 4 measured |
| OTIS Mock AIME | 13.8% | 84.4% | Qwen3.5-Flash |
| FrontierMath, tiers 1 to 3 | Not measured | 18.2% | Only Qwen3.5-Flash measured |
| MATH level 5 | 64.9% | Not measured | Only Phi 4 measured |
| LMArena Text: math | 1246 | 1407 | Qwen3.5-Flash |
| LMArena Text: mathematical work | 1254 | 1413 | Qwen3.5-Flash |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index04
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| MMLU Pro | Not measured | 84.1% | Only Qwen3.5-Flash measured |
| LegalBench (Vals AI) | Not measured | 84.3% | Only Qwen3.5-Flash measured |
| CaseLaw (Vals AI) | Not measured | 56.0% | Only Qwen3.5-Flash measured |
| CorpFin (Vals AI) | Not measured | 63.6% | Only Qwen3.5-Flash measured |
| TaxEval (Vals AI) | Not measured | 72.2% | Only Qwen3.5-Flash measured |
| MortgageTax (Vals AI) | Not measured | 67.4% | Only Qwen3.5-Flash measured |
| MedCode (Vals AI) | Not measured | 33.0% | Only Qwen3.5-Flash measured |
| MMLU Pro (Artificial Analysis run) | 71.4% | Not measured | Only Phi 4 measured |
| SimpleQA Verified | Not measured | 20.3% | Only Qwen3.5-Flash measured |
| MMLU | 84.8% | Not measured | Only Phi 4 measured |
| LMArena Text: science | 1206 | 1415 | Qwen3.5-Flash |
| LMArena Text: medicine and healthcare | 1202 | 1407 | Qwen3.5-Flash |
| LMArena Text: legal and government | 1241 | 1398 | Qwen3.5-Flash |
| LMArena Text: business and finance | 1199 | 1394 | Qwen3.5-Flash |
| Neither model has a result on the other 3 boards here | |||
Web designNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Neither model has a result on 9 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index016
| Benchmark | Phi 4 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| SAGE (Vals AI) | Not measured | 42.5% | Only Qwen3.5-Flash measured |
| MedScribe (Vals AI) | Not measured | 70.6% | Only Qwen3.5-Flash measured |
| IFBench | 23.5% | Not measured | Only Phi 4 measured |
| Long context reasoning (AA-LCR) | 0.0% | Not measured | Only Phi 4 measured |
| DTBench | Not measured | 82.9% | Only Qwen3.5-Flash measured |
| LMCA | Not measured | 29.1% | Only Qwen3.5-Flash measured |
| Creative writing (Lech Mazur) | 62.6% | Not measured | Only Phi 4 measured |
| LMArena Text | 1217 | 1397 | Qwen3.5-Flash |
| LMArena Text: instruction following | 1201 | 1374 | Qwen3.5-Flash |
| LMArena Text: creative writing | 1181 | 1343 | Qwen3.5-Flash |
| LMArena Text: English | 1231 | 1404 | Qwen3.5-Flash |
| LMArena Text: non-English | 1197 | 1385 | Qwen3.5-Flash |
| LMArena Text: Chinese | 1212 | 1445 | Qwen3.5-Flash |
| LMArena Text: German | 1222 | 1390 | Qwen3.5-Flash |
| LMArena Text: Japanese | 1158 | 1369 | Qwen3.5-Flash |
| LMArena Text: Korean | 1151 | 1344 | Qwen3.5-Flash |
| LMArena Text: French | 1224 | 1413 | Qwen3.5-Flash |
| LMArena Text: Spanish | 1234 | 1400 | Qwen3.5-Flash |
| LMArena Text: Russian | 1209 | 1380 | Qwen3.5-Flash |
| LMArena Text: Polish | Not measured | 1376 | Only Qwen3.5-Flash measured |
| LMArena Text: multi-turn | 1206 | 1393 | Qwen3.5-Flash |
| LMArena Text: longer queries | 1217 | 1392 | Qwen3.5-Flash |
| LMArena Text: writing and language | 1198 | 1369 | Qwen3.5-Flash |
| LMArena Text: entertainment and media | 1162 | 1347 | Qwen3.5-Flash |
| Neither model has a result on the other 22 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Phi 4 | Qwen3.5-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
Phi 4 costs less
Repository review
50K input + 3K output tokens
Phi 4 costs less
Agent loop
200K input + 10K output tokens
Phi 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 | Microsoft Phi 4 | Qwen3.5-Flash |
|---|---|---|
| Maker | Microsoft | Qwen |
| Weights | Open weights | No public weights listed |
| Released | January 10, 2025 | February 25, 2026 |
| Context window | 16K | 1M |
| Input $/Mtok | $0.07 | $0.065 |
| Output $/Mtok | $0.14 | $0.26 |
| Coding index | Not benchmarked | 41.1 |
| Independent measurements behind it | 0 | 2 |
| Cost per solved task | Not computable | $0.40 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Phi 4 better than Qwen3.5-Flash for coding?
Only Qwen3.5-Flash has a coding score, 41.1 on the Vibe Coding Index; Phi 4 has none, so the two cannot be ranked on coding. Pick Phi 4 for output tokens 1.9x cheaper ($0.14 vs $0.26 per million).
Which is cheaper, Phi 4 or Qwen3.5-Flash?
Phi 4 costs $0.07 per million input tokens and $0.14 per million output tokens; Qwen3.5-Flash costs $0.065 and $0.26. Cost per solved task is known for Qwen3.5-Flash only.
Which has the bigger context window, Phi 4 or Qwen3.5-Flash?
Qwen3.5-Flash, with 1M tokens against 16K.
How many benchmarks is the Phi 4 vs Qwen3.5-Flash comparison based on?
30 benchmarks have a result for both models as of October 21, 2026. Phi 4's coding index rests on 0 independent benchmarks and Qwen3.5-Flash's on 2. Where only one model has a result, the page says so instead of naming a winner.