o4 Mini vs Qwen3.5-Flash
Qwen3.5-Flash costs 16.9x less per output token than o4 Mini ($0.26 vs $4.40 per million). Updated October 22, 2026; 49 benchmarks have a result for both.
o4 Mini or Qwen3.5-Flash: which to pick
Only Qwen3.5-Flash has a coding score, 41.1 on the Vibe Coding Index; o4 Mini has none, so the two cannot be ranked on coding.
Pick o4 Mini for work measured by Epoch Capabilities Index or Chess puzzles, where it leads.
- Shared results
- 49
- o4 Mini only
- 49
- Qwen3.5-Flash only
- 6
- 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 o4 Mini has a AA Intelligence Index result, 16.7.
Directional only
Reasoning
GPQA Diamond
Qwen3.5-Flash
Qwen3.5-Flash leads, 82.8% against 74.5%.
Same board, both measured
Math
AIME
Qwen3.5-Flash
Qwen3.5-Flash leads, 92.5% against 83.7%.
Same board, both measured
Knowledge
MMLU Pro
Qwen3.5-Flash
Qwen3.5-Flash leads, 84.1% against 80.6%.
Same board, both measured
Web design
Design Arena: websites
No call
Only o4 Mini has a Design Arena: websites result, 985.
Directional only
Long documents
Listed context window
Qwen3.5-Flash
Qwen3.5-Flash takes 1M tokens against 200K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5-Flash
o4 Mini $0.0033, 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
- o4 Mini not benchmarked, Qwen3.5-Flash 41.1 from 2 benchmarks.
- Widest category
- Reasoning, 7.9 points apart on average over 8 shared benchmarks.
- Widest single gap
- FrontierMath, tiers 1 to 3: o4 Mini 36.1% against Qwen3.5-Flash 18.2%, 17.9 points apart on a 0 to 100 scale.
- Output price
- o4 Mini $4.40 against Qwen3.5-Flash $0.26 per million output tokens, 16.9x apart.
- Context window
- o4 Mini takes 200K 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 | o4 Mini | Bars | Qwen3.5-Flash | Ties |
|---|---|---|---|---|
| Coding | 0 | 3 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 1 | 7 | ||
| Math | 1 | 4 | ||
| Knowledge | 2 | 9 | ||
| General | 0 | 21 | ||
| All shared boards | 5 | 44 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index03
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Aider polyglot | 72.0% | Not measured | Only o4 Mini measured |
| SWE-bench Verified | 64.6% | Not measured | Only o4 Mini measured |
| SWE-bench Multimodal | 33.9% | Not measured | Only o4 Mini measured |
| LMArena WebDev | Not measured | 1244 | Only Qwen3.5-Flash measured |
| LiveCodeBench (Vals AI) | 82.2% | 83.3% | Qwen3.5-Flash |
| SWE-bench Verified (Vals AI) | Not measured | 64.4% | Only Qwen3.5-Flash measured |
| LiveCodeBench (Artificial Analysis run) | 85.9% | Not measured | Only o4 Mini measured |
| Terminal-Bench Hard (Artificial Analysis run) | 15.2% | Not measured | Only o4 Mini measured |
| GSO-Bench | 3.6% | Not measured | Only o4 Mini measured |
| WeirdML | 52.6% | Not measured | Only o4 Mini measured |
| ALE-Bench | Not measured | 265.9 | Only Qwen3.5-Flash measured |
| LMArena Text: coding | 1368 | 1412 | Qwen3.5-Flash |
| LMArena Text: software and IT | 1367 | 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 |
| SciCode | 10.8% | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 23 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 16.7 | Not measured | Only o4 Mini measured |
| Epoch Capabilities Index | 145.5 | 143.5 | o4 Mini |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index3 boards, none shared
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 55.6% | Not measured | Only o4 Mini measured |
| METR time horizons | 63.9% | Not measured | Only o4 Mini measured |
| Berkeley Function Calling Leaderboard (BFCL) | 53.2% | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 38 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index17
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 74.5% | 82.8% | Qwen3.5-Flash |
| MMMU Pro (Vals AI) | 79.7% | 81.9% | Qwen3.5-Flash |
| GPQA Diamond (Artificial Analysis run) | 78.4% | Not measured | Only o4 Mini measured |
| Humanity's Last Exam (Artificial Analysis run) | 16.5% | Not measured | Only o4 Mini measured |
| GPQA Diamond (Epoch AI run) | 79.6% | 82.3% | Qwen3.5-Flash |
| ARC-AGI | 58.7% | Not measured | Only o4 Mini measured |
| ARC-AGI-2 | 6.1% | Not measured | Only o4 Mini measured |
| SimpleBench | 38.7% | Not measured | Only o4 Mini measured |
| Chess puzzles | 22.0% | 14.0% | o4 Mini |
| Mystery game puzzles | 5.0% | 20.0% | Qwen3.5-Flash |
| VPCT | 57.5% | Not measured | Only o4 Mini measured |
| LMArena Text: hard prompts | 1351 | 1403 | Qwen3.5-Flash |
| LMArena Text: expert | 1343 | 1407 | Qwen3.5-Flash |
| LMArena Text: hard prompts in English | 1366 | 1409 | Qwen3.5-Flash |
| LMArena Vision: diagrams | 1197 | Not measured | Only o4 Mini measured |
| LMArena Vision: homework | 1234 | Not measured | Only o4 Mini measured |
| Kagi LLM Benchmark | 67.6% | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 5 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index14
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AIME | 83.7% | 92.5% | Qwen3.5-Flash |
| MATH 500 (Vals AI) | 94.2% | Not measured | Only o4 Mini measured |
| MGSM (Vals AI) | 93.4% | Not measured | Only o4 Mini measured |
| AA Math Index | 90.7 | Not measured | Only o4 Mini measured |
| AIME 2025 (Artificial Analysis run) | 90.7% | Not measured | Only o4 Mini measured |
| OTIS Mock AIME | 81.7% | 84.4% | Qwen3.5-Flash |
| FrontierMath, tiers 1 to 3 | 36.1% | 18.2% | o4 Mini |
| FrontierMath, tier 4 | 4.9% | Not measured | Only o4 Mini measured |
| MATH level 5 | 97.8% | Not measured | Only o4 Mini measured |
| LMArena Text: math | 1389 | 1407 | Qwen3.5-Flash |
| LMArena Text: mathematical work | 1379 | 1413 | Qwen3.5-Flash |
| Neither model has a result on the other 2 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index29
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| MMLU Pro | 80.6% | 84.1% | Qwen3.5-Flash |
| LegalBench (Vals AI) | 79.2% | 84.3% | Qwen3.5-Flash |
| CaseLaw (Vals AI) | Not measured | 56.0% | Only Qwen3.5-Flash measured |
| CorpFin (Vals AI) | 59.0% | 63.6% | Qwen3.5-Flash |
| TaxEval (Vals AI) | 74.8% | 72.2% | o4 Mini |
| MortgageTax (Vals AI) | 64.8% | 67.4% | Qwen3.5-Flash |
| MedQA (Vals AI) | 96.0% | Not measured | Only o4 Mini measured |
| MedCode (Vals AI) | 33.8% | 33.0% | o4 Mini |
| MMLU Pro (Artificial Analysis run) | 83.2% | Not measured | Only o4 Mini measured |
| SimpleQA Verified | 19.6% | 20.3% | Qwen3.5-Flash |
| GeoBench | 64.0% | Not measured | Only o4 Mini measured |
| LMArena Text: science | 1354 | 1415 | Qwen3.5-Flash |
| LMArena Text: medicine and healthcare | 1361 | 1407 | Qwen3.5-Flash |
| LMArena Text: legal and government | 1350 | 1398 | Qwen3.5-Flash |
| LMArena Text: business and finance | 1325 | 1394 | Qwen3.5-Flash |
| FACTS Benchmark Suite | 28.1% | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 2 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 985 | Not measured | Only o4 Mini measured |
| Design Arena: UI components | 983 | Not measured | Only o4 Mini measured |
| Design Arena: game dev | 1003 | Not measured | Only o4 Mini measured |
| Design Arena: data viz | 991 | Not measured | Only o4 Mini measured |
| Design Arena: 3D | 854 | Not measured | Only o4 Mini measured |
| Design Arena: all code categories | 976 | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 3 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index021
| Benchmark | o4 Mini | Qwen3.5-Flash | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 41.1% | 42.5% | Qwen3.5-Flash |
| MedScribe (Vals AI) | 69.1% | 70.6% | Qwen3.5-Flash |
| IFBench | 68.7% | Not measured | Only o4 Mini measured |
| Long context reasoning (AA-LCR) | 61.0% | Not measured | Only o4 Mini measured |
| DTBench | 77.6% | 82.9% | Qwen3.5-Flash |
| LMCA | 26.5% | 29.1% | Qwen3.5-Flash |
| Fiction.LiveBench | 77.8% | Not measured | Only o4 Mini measured |
| Creative writing (Lech Mazur) | 75.0% | Not measured | Only o4 Mini measured |
| LMArena Text | 1353 | 1397 | Qwen3.5-Flash |
| LMArena Text: instruction following | 1320 | 1374 | Qwen3.5-Flash |
| LMArena Text: creative writing | 1294 | 1343 | Qwen3.5-Flash |
| LMArena Vision | 1194 | Not measured | Only o4 Mini measured |
| LMArena Text: English | 1367 | 1404 | Qwen3.5-Flash |
| LMArena Text: non-English | 1337 | 1385 | Qwen3.5-Flash |
| LMArena Text: Chinese | 1354 | 1445 | Qwen3.5-Flash |
| LMArena Text: German | 1336 | 1390 | Qwen3.5-Flash |
| LMArena Text: Japanese | 1308 | 1369 | Qwen3.5-Flash |
| LMArena Text: Korean | 1312 | 1344 | Qwen3.5-Flash |
| LMArena Text: French | 1364 | 1413 | Qwen3.5-Flash |
| LMArena Text: Spanish | 1346 | 1400 | Qwen3.5-Flash |
| LMArena Text: Russian | 1334 | 1380 | Qwen3.5-Flash |
| LMArena Text: Polish | 1358 | 1376 | Qwen3.5-Flash |
| LMArena Text: multi-turn | 1350 | 1393 | Qwen3.5-Flash |
| LMArena Text: longer queries | 1315 | 1392 | Qwen3.5-Flash |
| LMArena Text: writing and language | 1316 | 1369 | Qwen3.5-Flash |
| LMArena Text: entertainment and media | 1308 | 1347 | Qwen3.5-Flash |
| LMArena Vision: English | 1200 | Not measured | Only o4 Mini measured |
| LMArena Vision: Chinese | 1218 | Not measured | Only o4 Mini measured |
| LMArena Vision: reading text | 1197 | Not measured | Only o4 Mini measured |
| LMArena Vision: humor | 1199 | Not measured | Only o4 Mini measured |
| LMArena Vision: captioning | 1204 | Not measured | Only o4 Mini measured |
| LMArena Vision: recognizing things | 1218 | Not measured | Only o4 Mini measured |
| LMArena Vision: creative writing | 1166 | Not measured | Only o4 Mini measured |
| Neither model has a result on the other 13 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | o4 Mini | 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
Qwen3.5-Flash costs less
Repository review
50K input + 3K output tokens
Qwen3.5-Flash costs less
Agent loop
200K input + 10K output tokens
Qwen3.5-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 | OpenAI o4 Mini | Qwen3.5-Flash |
|---|---|---|
| Maker | OpenAI | Qwen |
| Weights | No public weights listed | No public weights listed |
| Released | April 16, 2025 | February 25, 2026 |
| Context window | 200K | 1M |
| Input $/Mtok | $1.10 | $0.065 |
| Output $/Mtok | $4.40 | $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 o4 Mini better than Qwen3.5-Flash for coding?
Only Qwen3.5-Flash has a coding score, 41.1 on the Vibe Coding Index; o4 Mini has none, so the two cannot be ranked on coding. Pick o4 Mini for work measured by Epoch Capabilities Index or Chess puzzles, where it leads.
Which is cheaper, o4 Mini or Qwen3.5-Flash?
o4 Mini costs $1.10 per million input tokens and $4.40 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, o4 Mini or Qwen3.5-Flash?
Qwen3.5-Flash, with 1M tokens against 200K.
How many benchmarks is the o4 Mini vs Qwen3.5-Flash comparison based on?
49 benchmarks have a result for both models as of October 22, 2026. o4 Mini'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.