Kimi K2 Thinking vs Qwen3.5-Flash
Updated October 21, 2026. 11 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.
Decision reading
Pick Kimi K2 Thinking for coding: it scores 63.4 on the Vibe Coding Index against 6.2 for Qwen3.5-Flash.
Pick Qwen3.5-Flash when output tokens cost 9.6x less, or when a solved task costs $0.40 against $0.61.
- Shared results
- 11
- Kimi K2 Thinking only
- 19
- Qwen3.5-Flash only
- 44
- Like-for-like categories
- 5 of 9
Shared results can support a head-to-head reading. Results only one model has describe coverage, not superiority.
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, four public coding benchmarks
Kimi K2 Thinking
Kimi K2 Thinking scores 63.4 against 6.2.
One benchmark behind each score
Intelligence
AA Intelligence Index
No call
Only Kimi K2 Thinking has a AA Intelligence Index result, 22.0.
Directional only
Reasoning
GPQA Diamond
Qwen3.5-Flash
Qwen3.5-Flash leads, 82.8% against 78.5%.
Same board, both measured
Math
AIME
Qwen3.5-Flash
Qwen3.5-Flash leads, 92.5% against 85.4%.
Same board, both measured
Knowledge
MMLU Pro
Qwen3.5-Flash
Qwen3.5-Flash leads, 84.1% against 81.1%.
Same board, both measured
Web design
Design Arena: websites
No call
Only Kimi K2 Thinking has a Design Arena: websites result, 1113.
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 Thinking $0.0019, Qwen3.5-Flash $0.0002 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
Qwen3.5-Flash
Kimi K2 Thinking $0.61, Qwen3.5-Flash $0.40.
Published attempt cost and pass rate
At a glance
- Coding index
- Kimi K2 Thinking 63.4 from 1 benchmark, Qwen3.5-Flash 6.2 from 1 benchmark.
- Widest category
- Coding, 11.8 points apart on average over 3 shared benchmarks.
- Widest single gap
- LiveCodeBench (Vals AI): Kimi K2 Thinking 63.1% against Qwen3.5-Flash 83.3%, 20.1 points apart on a 0 to 100 scale.
- Output price
- Kimi K2 Thinking $2.50 against Qwen3.5-Flash $0.26 per million output tokens, 9.6x apart.
- Context window
- Kimi K2 Thinking 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 Thinking | Bars | Qwen3.5-Flash | Ties |
|---|---|---|---|---|
| Coding | 1 | 2 | ||
| Intelligence | 1 | 0 | ||
| Reasoning | 0 | 1 | ||
| Math | 0 | 1 | ||
| Knowledge | 1 | 4 | ||
| All shared boards | 3 | 8 |
CodingLike-for-likeFour of these boards feed the Vibe Coding Index12
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| SWE-bench Verified | 63.4% | Not measured | Only Kimi K2 Thinking measured |
| LMArena WebDev | Not measured | 1244 | Only Qwen3.5-Flash measured |
| LiveCodeBench (Vals AI) | 63.1% | 83.3% | Qwen3.5-Flash |
| SWE-bench Verified (Vals AI) | 60.2% | 64.4% | Qwen3.5-Flash |
| LiveCodeBench (Artificial Analysis run) | 85.3% | Not measured | Only Kimi K2 Thinking measured |
| Terminal-Bench Hard (Artificial Analysis run) | 31.1% | Not measured | Only Kimi K2 Thinking measured |
| Terminal-Bench | 35.7% | Not measured | Only Kimi K2 Thinking measured |
| WeirdML | 42.8% | Not measured | Only Kimi K2 Thinking measured |
| ALE-Bench | 597.5 | 265.9 | Kimi K2 Thinking |
| LMArena Text: coding | Not measured | 1412 | Only Qwen3.5-Flash measured |
| LMArena Text: software and IT | Not measured | 1416 | Only Qwen3.5-Flash measured |
| 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 25 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AA Intelligence Index | 22.0 | Not measured | Only Kimi K2 Thinking measured |
| Epoch Capabilities Index | 145.8 | 143.5 | Kimi K2 Thinking |
Agentic workDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| τ²-Bench Telecom | 93.0% | Not measured | Only Kimi K2 Thinking measured |
| METR time horizons | 59.2% | Not measured | Only Kimi K2 Thinking measured |
| Neither model has a result on the other 37 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| GPQA Diamond | 78.5% | 82.8% | Qwen3.5-Flash |
| MMMU Pro (Vals AI) | Not measured | 81.9% | Only Qwen3.5-Flash measured |
| GPQA Diamond (Artificial Analysis run) | 83.8% | Not measured | Only Kimi K2 Thinking measured |
| Humanity's Last Exam (Artificial Analysis run) | 23.8% | Not measured | Only Kimi K2 Thinking measured |
| GPQA Diamond (Epoch AI run) | Not measured | 82.3% | Only Qwen3.5-Flash 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 | Not measured | 1403 | Only Qwen3.5-Flash measured |
| LMArena Text: expert | Not measured | 1407 | Only Qwen3.5-Flash measured |
| LMArena Text: hard prompts in English | Not measured | 1409 | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 11 boards here | |||
MathLike-for-likePublic boards, shown as published, kept out of the index01
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| AIME | 85.4% | 92.5% | Qwen3.5-Flash |
| MGSM (Vals AI) | 90.2% | Not measured | Only Kimi K2 Thinking measured |
| AA Math Index | 94.7 | Not measured | Only Kimi K2 Thinking measured |
| AIME 2025 (Artificial Analysis run) | 94.7% | Not measured | Only Kimi K2 Thinking measured |
| 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 | Not measured | 1407 | Only Qwen3.5-Flash measured |
| LMArena Text: mathematical work | Not measured | 1413 | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 5 boards here | |||
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index14
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| MMLU Pro | 81.1% | 84.1% | Qwen3.5-Flash |
| LegalBench (Vals AI) | 80.2% | 84.3% | Qwen3.5-Flash |
| CaseLaw (Vals AI) | 65.7% | 56.0% | Kimi K2 Thinking |
| CorpFin (Vals AI) | 60.6% | 63.6% | Qwen3.5-Flash |
| TaxEval (Vals AI) | 71.7% | 72.2% | Qwen3.5-Flash |
| MortgageTax (Vals AI) | Not measured | 67.4% | Only Qwen3.5-Flash measured |
| MedQA (Vals AI) | 92.6% | Not measured | Only Kimi K2 Thinking measured |
| MedCode (Vals AI) | Not measured | 33.0% | Only Qwen3.5-Flash measured |
| MMLU Pro (Artificial Analysis run) | 84.8% | Not measured | Only Kimi K2 Thinking measured |
| SimpleQA Verified | Not measured | 20.3% | Only Qwen3.5-Flash measured |
| LMArena Text: science | Not measured | 1415 | Only Qwen3.5-Flash measured |
| LMArena Text: medicine and healthcare | Not measured | 1407 | Only Qwen3.5-Flash measured |
| LMArena Text: legal and government | Not measured | 1398 | Only Qwen3.5-Flash measured |
| LMArena Text: business and finance | Not measured | 1394 | Only Qwen3.5-Flash measured |
| Neither model has a result on the other 3 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Kimi K2 Thinking | Qwen3.5-Flash | Leader |
|---|---|---|---|
| Design Arena: websites | 1113 | Not measured | Only Kimi K2 Thinking measured |
| Neither model has a result on the other 8 boards here | |||
GeneralDirectional onlyPublic boards, shown as published, kept out of the index24 boards, none shared
| Benchmark | Kimi K2 Thinking | 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 | 68.1% | Not measured | Only Kimi K2 Thinking measured |
| Long context reasoning (AA-LCR) | 72.0% | Not measured | Only Kimi K2 Thinking measured |
| DTBench | Not measured | 82.9% | Only Qwen3.5-Flash measured |
| LMCA | Not measured | 29.1% | Only Qwen3.5-Flash measured |
| CL-bench | 17.6% | Not measured | Only Kimi K2 Thinking measured |
| LMArena Text | Not measured | 1397 | Only Qwen3.5-Flash measured |
| LMArena Text: instruction following | Not measured | 1374 | Only Qwen3.5-Flash measured |
| LMArena Text: creative writing | Not measured | 1343 | Only Qwen3.5-Flash measured |
| LMArena Text: English | Not measured | 1404 | Only Qwen3.5-Flash measured |
| LMArena Text: non-English | Not measured | 1385 | Only Qwen3.5-Flash measured |
| LMArena Text: Chinese | Not measured | 1445 | Only Qwen3.5-Flash measured |
| LMArena Text: German | Not measured | 1390 | Only Qwen3.5-Flash measured |
| LMArena Text: Japanese | Not measured | 1369 | Only Qwen3.5-Flash measured |
| LMArena Text: Korean | Not measured | 1344 | Only Qwen3.5-Flash measured |
| LMArena Text: French | Not measured | 1413 | Only Qwen3.5-Flash measured |
| LMArena Text: Spanish | Not measured | 1400 | Only Qwen3.5-Flash measured |
| LMArena Text: Russian | Not measured | 1380 | Only Qwen3.5-Flash measured |
| LMArena Text: Polish | Not measured | 1376 | Only Qwen3.5-Flash measured |
| LMArena Text: multi-turn | Not measured | 1393 | Only Qwen3.5-Flash measured |
| LMArena Text: longer queries | Not measured | 1392 | Only Qwen3.5-Flash measured |
| LMArena Text: writing and language | Not measured | 1369 | Only Qwen3.5-Flash measured |
| LMArena Text: entertainment and media | Not measured | 1347 | Only Qwen3.5-Flash measured |
| 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 | Kimi K2 Thinking | 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 Thinking | Qwen3.5-Flash |
|---|---|---|
| Maker | Moonshot AI | Qwen |
| Weights | Open weights | No public weights listed |
| Released | November 6, 2025 | February 25, 2026 |
| Context window | 262K | 1M |
| Input $/Mtok | $0.60 | $0.065 |
| Output $/Mtok | $2.50 | $0.26 |
| Coding index | 63.4 | 6.2 |
| Independent measurements behind it | 1 | 1 |
| Cost per solved task | $0.61 | $0.40 |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Kimi K2 Thinking better than Qwen3.5-Flash for coding?
Pick Kimi K2 Thinking for coding: it scores 63.4 on the Vibe Coding Index against 6.2 for Qwen3.5-Flash. Pick Qwen3.5-Flash when output tokens cost 9.6x less, or when a solved task costs $0.40 against $0.61.
Which is cheaper, Kimi K2 Thinking or Qwen3.5-Flash?
Kimi K2 Thinking costs $0.60 per million input tokens and $2.50 per million output tokens; Qwen3.5-Flash costs $0.065 and $0.26. Per solved SWE-bench Verified task, Kimi K2 Thinking costs $0.61 and Qwen3.5-Flash $0.40.
Which has the bigger context window, Kimi K2 Thinking or Qwen3.5-Flash?
Qwen3.5-Flash, with 1M tokens against 262K.
How many benchmarks is the Kimi K2 Thinking vs Qwen3.5-Flash comparison based on?
11 benchmarks have a result for both models as of October 21, 2026. Kimi K2 Thinking's coding index rests on 1 independent benchmark and Qwen3.5-Flash's on 1. Where only one model has a result, the page says so instead of naming a winner.