Kimi K2.5 vs Qwen3.5-Flash
Qwen3.5-Flash leads Kimi K2.5 on coding, 41.1 to 38.6 on the Vibe Coding Index, and Qwen3.5-Flash costs 11.0x less per output token ($0.26 vs $2.85 per million). Updated October 23, 2026; 47 benchmarks have a result for both.
Kimi K2.5 or Qwen3.5-Flash: which to pick
Pick Qwen3.5-Flash for coding: it scores 41.1 on the Vibe Coding Index against 38.6 for Kimi K2.5, though on 2 benchmarks against 3.
Pick Kimi K2.5 for a lower cost per solved task ($0.24 against $0.40) and work measured by LMArena WebDev or LiveCodeBench (Vals AI), where it leads.
- Shared results
- 47
- Kimi K2.5 only
- 60
- Qwen3.5-Flash only
- 8
- 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
Qwen3.5-Flash
Qwen3.5-Flash scores 41.1 against 38.6.
3 and 2 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only Kimi K2.5 has a AA Intelligence Index result, 23.5.
Directional only
Reasoning
GPQA Diamond
Kimi K2.5
Kimi K2.5 leads, 84.1% against 82.8%.
Same board, both measured
Math
AIME
Kimi K2.5
Kimi K2.5 leads, 95.6% against 92.5%.
Same board, both measured
Knowledge
MMLU Pro
Kimi K2.5
Kimi K2.5 leads, 85.9% against 84.1%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Kimi K2.5 has a Design Arena: websites result, 1248.
Directional only
Long documents
Listed context window
Qwen3.5-Flash
Qwen3.5-Flash takes 1M tokens against 262K.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Qwen3.5-Flash
Kimi K2.5 $0.0020, Qwen3.5-Flash $0.0002 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Kimi K2.5
Kimi K2.5 $0.24, Qwen3.5-Flash $0.40.
Published attempt cost and pass rate
At a glance
- Coding index
- Kimi K2.5 38.6 from 3 benchmarks, Qwen3.5-Flash 41.1 from 2 benchmarks.
- Widest category
- Coding, 16.2 points apart on average over 8 shared benchmarks.
- Widest single gap
- LMArena WebDev: React: Kimi K2.5 1429 against Qwen3.5-Flash 1229, 33.3 points apart on a 0 to 100 scale.
- Output price
- Kimi K2.5 $2.85 against Qwen3.5-Flash $0.26 per million output tokens, 11.0x apart.
- Context window
- Kimi K2.5 takes 262K 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 | Kimi K2.5 | Bars | Qwen3.5-Flash | Ties |
|---|---|---|---|---|
| Coding | 8 | 0 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 5 | 0 | ||
| Math | 3 | 0 | ||
| Knowledge | 10 | 1 | ||
| General | 19 | 0 | ||
| All shared boards | 46 | 1 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index80
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| SWE-bench Verified | 70.8% | Not measured | Only Kimi K2.5 measured |
| SWE-bench Multilingual | 67.3% | Not measured | Only Kimi K2.5 measured |
| LMArena WebDev | 1437 | 1244 | Kimi K2.5 |
| AA Coding Index | 46.8 | Not measured | Only Kimi K2.5 measured |
| LiveCodeBench (Vals AI) | 83.9% | 83.3% | Kimi K2.5 |
| SWE-bench Verified (Vals AI) | 70.0% | 64.4% | Kimi K2.5 |
| Vibe Code Bench (Vals AI) | 17.5% | Not measured | Only Kimi K2.5 measured |
| Code migration (Vals AI) | 7.0% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench 2.1 (Vals AI) | 42.0% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 34.8% | Not measured | Only Kimi K2.5 measured |
| Terminal-Bench | 43.2% | Not measured | Only Kimi K2.5 measured |
| WeirdML | 45.6% | Not measured | Only Kimi K2.5 measured |
| ALE-Bench | 821.6 | 265.9 | Kimi K2.5 |
| LMArena Text: coding | 1484 | 1412 | Kimi K2.5 |
| LMArena Text: software and IT | 1471 | 1416 | Kimi K2.5 |
| LMArena WebDev: React | 1429 | 1229 | Kimi K2.5 |
| LMArena WebDev: HTML | 1427 | 1291 | Kimi K2.5 |
| LMArena WebDev: from an image | 1439 | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Codebase QnA | 13.1% | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Refactoring | 20.9% | Not measured | Only Kimi K2.5 measured |
| SWE Atlas: Test Writing | 25.8% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 22 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 23.5 | Not measured | Only Kimi K2.5 measured |
| Epoch Capabilities Index | 148.1 | 143.5 | Kimi K2.5 |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index12 boards, none shared
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Design Arena: agents building web apps | 1136 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building full-stack apps | 1114 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building mobile apps | 1147 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building Android apps | 1120 | Not measured | Only Kimi K2.5 measured |
| Design Arena: agents building Godot games | 1219 | Not measured | Only Kimi K2.5 measured |
| Finance Agent (Vals AI) | 35.8% | Not measured | Only Kimi K2.5 measured |
| Legal Research Bench (Vals AI) | 15.9% | Not measured | Only Kimi K2.5 measured |
| Excel Modeling Benchmark (Vals AI) | 28.5% | Not measured | Only Kimi K2.5 measured |
| τ²-Bench Telecom | 95.9% | Not measured | Only Kimi K2.5 measured |
| OSWorld | 63.3% | Not measured | Only Kimi K2.5 measured |
| Vending-Bench 2 | $1,198 | Not measured | Only Kimi K2.5 measured |
| MCP Atlas | 64.4% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 30 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index50
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 84.1% | 82.8% | Kimi K2.5 |
| MMMU Pro (Vals AI) | 84.3% | 81.9% | Kimi K2.5 |
| GPQA Diamond (Artificial Analysis run) | 87.9% | Not measured | Only Kimi K2.5 measured |
| Humanity's Last Exam (Artificial Analysis run) | 30.7% | Not measured | Only Kimi K2.5 measured |
| GPQA Diamond (Epoch AI run) | Not measured | 82.3% | Only Qwen3.5-Flash measured |
| ARC-AGI | 65.3% | Not measured | Only Kimi K2.5 measured |
| ARC-AGI-2 | 11.8% | Not measured | Only Kimi K2.5 measured |
| SimpleBench | 46.8% | Not measured | Only Kimi K2.5 measured |
| 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 | 1453 | 1403 | Kimi K2.5 |
| LMArena Text: expert | 1466 | 1407 | Kimi K2.5 |
| LMArena Text: hard prompts in English | 1460 | 1409 | Kimi K2.5 |
| LMArena Vision: diagrams | 1282 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: homework | 1297 | Not measured | Only Kimi K2.5 measured |
| Kagi LLM Benchmark | 78.5% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 7 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index30
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AIME | 95.6% | 92.5% | Kimi K2.5 |
| OTIS Mock AIME | Not measured | 84.4% | Only Qwen3.5-Flash measured |
| FrontierMath, tiers 1 to 3 | Not measured | 18.2% | Only Qwen3.5-Flash measured |
| LMArena Text: math | 1470 | 1407 | Kimi K2.5 |
| LMArena Text: mathematical work | 1473 | 1413 | Kimi K2.5 |
| MathArena | 17.9% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 8 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index101
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| MMLU Pro | 85.9% | 84.1% | Kimi K2.5 |
| LegalBench (Vals AI) | Not measured | 84.3% | Only Qwen3.5-Flash measured |
| CaseLaw (Vals AI) | 58.7% | 56.0% | Kimi K2.5 |
| CorpFin (Vals AI) | 68.3% | 63.6% | Kimi K2.5 |
| TaxEval (Vals AI) | 74.2% | 72.2% | Kimi K2.5 |
| MortgageTax (Vals AI) | 66.5% | 67.4% | Qwen3.5-Flash |
| MedQA (Vals AI) | 94.4% | Not measured | Only Kimi K2.5 measured |
| MedCode (Vals AI) | 39.3% | 33.0% | Kimi K2.5 |
| SimpleQA Verified | 34.3% | 20.3% | Kimi K2.5 |
| LMArena Text: science | 1459 | 1415 | Kimi K2.5 |
| LMArena Text: medicine and healthcare | 1448 | 1407 | Kimi K2.5 |
| LMArena Text: legal and government | 1441 | 1397 | Kimi K2.5 |
| LMArena Text: business and finance | 1427 | 1394 | Kimi K2.5 |
| PRBench Finance | 46.5% | Not measured | Only Kimi K2.5 measured |
| PRBench Legal | 43.8% | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 5 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index8 boards, none shared
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1248 | Not measured | Only Kimi K2.5 measured |
| Design Arena: UI components | 1234 | Not measured | Only Kimi K2.5 measured |
| Design Arena: game dev | 1206 | Not measured | Only Kimi K2.5 measured |
| Design Arena: data viz | 1219 | Not measured | Only Kimi K2.5 measured |
| Design Arena: 3D | 1206 | Not measured | Only Kimi K2.5 measured |
| Design Arena: all code categories | 1236 | Not measured | Only Kimi K2.5 measured |
| Design Arena: SVG | 1149 | Not measured | Only Kimi K2.5 measured |
| Design Arena: ASCII art | 1165 | Not measured | Only Kimi K2.5 measured |
| Neither model has a result on the other 1 board here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index190
| Benchmark | Kimi K2.5 | Qwen3.5-Flash | Leader |
|---|---|---|---|
| SAGE (Vals AI) | 49.9% | 42.5% | Kimi K2.5 |
| MedScribe (Vals AI) | 76.4% | 70.6% | Kimi K2.5 |
| IFBench | 70.2% | Not measured | Only Kimi K2.5 measured |
| Long context reasoning (AA-LCR) | 78.0% | Not measured | Only Kimi K2.5 measured |
| DTBench | Not measured | 82.9% | Only Qwen3.5-Flash measured |
| LMCA | Not measured | 29.1% | Only Qwen3.5-Flash measured |
| Fiction.LiveBench | 86.1% | Not measured | Only Kimi K2.5 measured |
| CL-bench | 19.3% | Not measured | Only Kimi K2.5 measured |
| CL-bench Life | 13.2% | Not measured | Only Kimi K2.5 measured |
| LMArena Text | 1445 | 1397 | Kimi K2.5 |
| LMArena Text: instruction following | 1431 | 1375 | Kimi K2.5 |
| LMArena Text: creative writing | 1422 | 1343 | Kimi K2.5 |
| LMArena Vision | 1269 | Not measured | Only Kimi K2.5 measured |
| LMArena Text: English | 1454 | 1404 | Kimi K2.5 |
| LMArena Text: non-English | 1433 | 1385 | Kimi K2.5 |
| LMArena Text: Chinese | 1494 | 1446 | Kimi K2.5 |
| LMArena Text: German | 1441 | 1391 | Kimi K2.5 |
| LMArena Text: Japanese | 1422 | 1369 | Kimi K2.5 |
| LMArena Text: Korean | 1411 | 1344 | Kimi K2.5 |
| LMArena Text: French | 1454 | 1413 | Kimi K2.5 |
| LMArena Text: Spanish | 1450 | 1399 | Kimi K2.5 |
| LMArena Text: Russian | 1435 | 1380 | Kimi K2.5 |
| LMArena Text: Polish | 1446 | 1376 | Kimi K2.5 |
| LMArena Text: multi-turn | 1444 | 1393 | Kimi K2.5 |
| LMArena Text: longer queries | 1444 | 1392 | Kimi K2.5 |
| LMArena Text: writing and language | 1425 | 1369 | Kimi K2.5 |
| LMArena Text: entertainment and media | 1417 | 1347 | Kimi K2.5 |
| LMArena Vision: English | 1274 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: Chinese | 1328 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: reading text | 1276 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: humor | 1284 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: captioning | 1257 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: recognizing things | 1285 | Not measured | Only Kimi K2.5 measured |
| LMArena Vision: creative writing | 1269 | Not measured | Only Kimi K2.5 measured |
| MultiChallenge | 61.4% | Not measured | Only Kimi K2.5 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 | Kimi K2.5 | 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 | MoonshotAI Kimi K2.5 | Qwen3.5-Flash |
|---|---|---|
| Maker | Moonshot AI | Qwen |
| Weights | Open weights | No public weights listed |
| Released | January 27, 2026 | February 25, 2026 |
| Context window | 262K | 1M |
| Input $/Mtok | $0.532 | $0.065 |
| Output $/Mtok | $2.85 | $0.26 |
| Coding index | 38.6 | 41.1 |
| Independent measurements behind it | 3 | 2 |
| Cost per solved task | $0.24 | $0.40 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Kimi K2.5 better than Qwen3.5-Flash for coding?
Pick Qwen3.5-Flash for coding: it scores 41.1 on the Vibe Coding Index against 38.6 for Kimi K2.5, though on 2 benchmarks against 3. Pick Kimi K2.5 for a lower cost per solved task ($0.24 against $0.40) and work measured by LMArena WebDev or LiveCodeBench (Vals AI), where it leads.
Which is cheaper, Kimi K2.5 or Qwen3.5-Flash?
Kimi K2.5 costs $0.532 per million input tokens and $2.85 per million output tokens; Qwen3.5-Flash costs $0.065 and $0.26. Per solved SWE-bench Verified task, Kimi K2.5 costs $0.24 and Qwen3.5-Flash $0.40.
Which has the bigger context window, Kimi K2.5 or Qwen3.5-Flash?
Qwen3.5-Flash, with 1M tokens against 262K.
How many benchmarks is the Kimi K2.5 vs Qwen3.5-Flash comparison based on?
47 benchmarks have a result for both models as of October 23, 2026. Kimi K2.5's coding index rests on 3 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.