Claude Sonnet 5.5 vs Kimi K3.1 Pro Together
Full profiles: Claude Sonnet 5.5 (Anthropic) and Kimi K3.1 Pro Together (Moonshot AI): every benchmark, price and rank.
Updated · Data from 10 sources
As of 9 Nov 2026, Claude Sonnet 5.5 is ahead of Kimi K3.1 Pro Together on quality (65.0 vs 60.5 on the BenchLeader Index). Choose Claude Sonnet 5.5 for maths (72 vs 66); choose Kimi K3.1 Pro Together for knowledge (68 vs 58).
Key facts (as of 9 Nov 2026)
- Claude Sonnet 5.5 scores 65.0 on the BenchLeader Index and Kimi K3.1 Pro Together scores 60.5 (BenchLeader, 9 Nov 2026).
- Claude Sonnet 5.5 costs $4.00 per 1M tokens blended (list price, 9 Nov 2026).
- Of the 7 benchmarks both models have, Claude Sonnet 5.5 leads 5 (BenchLeader, 9 Nov 2026).
Claude Sonnet 5.5 benchmarks max Anthropic
Kimi K3.1 Pro Together benchmarks max Moonshot AIAdd a third modelWhich to pick for…
The pick's numbers come first. Category scores on the BenchLeader scale (50 is the average model, 15 points one standard deviation). High confidence means a lead of half a standard deviation or more; under one point is called either.
| Use case | Pick | Why | Confidence |
|---|---|---|---|
| Maths | Claude Sonnet 5.5 | 72 vs 66 category score; FrontierMath Tiers 1–3 88.8% vs 78.3% | Medium |
| Reasoning | Either | 68 vs 67 category score; GPQA Diamond 95.6% vs 94.2% | Either |
| Knowledge | Kimi K3.1 Pro Together | 68 vs 58 category score; SimpleQA Verified 62.2% vs 46.5% | High |
| High volume on a budget | Neither flagship | A smaller model is usually the better fit: Cheapest good LLMs, Fastest LLMs | – |
Key differences
- Claude Sonnet 5.5 (max) leads on quality: 65.0 vs 60.5.
- Claude Sonnet 5.5 (max) is stronger in agents & tools, coding, long context, maths, reasoning.
- Kimi K3.1 Pro Together (max) is stronger in knowledge.
At a glance
| Spec | Claude Sonnet 5.5 | Kimi K3.1 Pro Together |
|---|---|---|
| Developer | Anthropic | Moonshot AI |
| Released | 28 Sep 2026 | 23 Oct 2026 |
| Context window (tokens) | 1,000,000 | – |
| Compared at | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) |
| Open weights | No | No |
| Price in / out / cached input per 1M | $2.00 / $10.00 / $0.100 | – |
Category by category
Category scores on the BenchLeader scale: 50 is the average evaluated model, 15 points is one standard deviation. A gap under one point is called level.
| Category | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) | Leader |
|---|---|---|---|
| Reasoning | 68.0 | 67.1 | level |
| Coding | 71.5 | – | not comparable |
| Agents & tools | 71.3 | – | not comparable |
| Maths | 72.0 | 65.8 | Claude Sonnet 5.5 |
| Knowledge | 58.0 | 67.6 | Kimi K3.1 Pro Together |
| Long context | 66.1 | – | not comparable |
On one chart
Each domain on the index's own scale, where 50 is an average model. Click a domain to see the benchmarks behind it. Pick up to 5 models from the list.
Not drawn, measured for fewer than two of these models: Coding, Agents & tools, Instruction following, Long context, Multimodal, Human preference.
Where sources disagree
Across the 7 benchmarks both have, Claude Sonnet 5.5 leads 5, Kimi K3.1 Pro Together leads 1 and 1 is a tie. Every overall index that rates both puts Claude Sonnet 5.5 ahead.
| Overall index | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) | Leader |
|---|---|---|---|
| BenchLeader Index | 65.0 | 60.5 | Claude Sonnet 5.5 |
Each publisher runs its own tasks, harnesses and effort settings, so their overall verdicts can differ; BenchLeader reconciles them on one scale. † measured at another effort setting of the same model (the publisher did not test the one compared here).
Price, speed and latency
List prices blended at three input tokens per output token. Per-task prices use the token counts on the methodology page. Cost, tokens and time per benchmark task are measured: Artificial Analysis’ averages over its whole Intelligence Index run.
| Measure | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) |
|---|---|---|
| Blended price per 1M tokens | $4.00 | – |
| Input / output per 1M | $2.00 / $10.00 | – / – |
| Cached input per 1M | $0.100 | – |
| Price per task: chat reply | $0.0038 | – |
| Price per task: summarize a 30-page report | $0.030 | – |
| Price per task: code edit | $0.027 | – |
| Price per task: agentic coding session | $0.160 | – |
| Price per task: structured extraction | $0.0060 | – |
| Agentic coding session, input mostly cached | $0.074 | – |
| Cost per benchmark task (AA Index) | $10.02 | – |
| Output tokens per task (AA Index) | 285k | – |
| Of which reasoning | 206k | – |
| Time per task (AA Index) | 31 min | – |
| Output speed | 152 tok/s | – |
| Time to first answer | 288.8 s | – |
| Time to a complete answer | 569.9 s | – |
Each model is compared at its best-ranked reasoning-effort setting. Claude Sonnet 5.5 (max) scores 65.0 and takes 289 s to its first answer token; Claude Sonnet 5.5 (xhigh) scores 62.7 in 27 s, Claude Sonnet 5.5 (high) scores 58.0 in 9 s. Kimi K3.1 Pro Together (max) scores 60.5. Higher effort means more thinking before the answer: better scores, longer waits and more tokens billed. How reasoning effort changes scores and cost.
Every benchmark
115 benchmarks, grouped by category; each name links to the board and its leaders. † measured at another effort setting of the same model, shown for reference and not counted as a win.
| Metric | Publisher | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) |
|---|---|---|---|
| BenchLeader Index | BenchLeader | 65.0 | 60.5 |
| Agents & tools score | BenchLeader | 71.3 | – |
| Coding score | BenchLeader | 71.5 | – |
| Knowledge score | BenchLeader | 58.0 | 67.6 |
| Long context score | BenchLeader | 66.1 | – |
| Maths score | BenchLeader | 72.0 | 65.8 |
| Reasoning score | BenchLeader | 68.0 | 67.1 |
| Blended price $/M | BenchLeader | $4.00 | – |
| Output speed | BenchLeader | 152 tok/s | – |
| Time to first answer | BenchLeader | 288.8 s | – |
| Context window | BenchLeader | 1,000,000 tokens | – |
| Reasoning | |||
| GPQA Diamond | Epoch AI Benchmarking Hub | 95.6% | 94.2% |
| Humanity's Last Exam | Scale AI / CAIS | 46.1%† | – |
| Arena Hard Prompts | Arena (LMArena) | 1498† | – |
| LiveBench 2.0 Reasoning | LiveBench | 91.6%† | – |
| LiveBench 1.0 Reasoning | LiveBench | 91.6% | – |
| Humanity's Last Exam (AA) | Artificial Analysis | 55.0% | – |
| HLE-Diamond (AA) | Artificial Analysis | 53.3% | – |
| ARC-AGI-1 | ARC Prize | 96.5% | – |
| ARC-AGI-2 | ARC Prize | 83.9%† | – |
| ARC-AGI-3 | ARC Prize | 72.4%† | – |
| CritPt | Artificial Analysis | 31.4% | – |
| CritPt v2 hard subset (AA) | Artificial Analysis | 59.0% | – |
| MysteryMechanism | Vals AI | 49.1%† | – |
| Chess Puzzles | Epoch AI Benchmarking Hub | 59.0% | 45.0% |
| Mystery Game Puzzles | Epoch AI Benchmarking Hub | 65.0% | 42.0% |
| LMCA | Epoch AI Benchmarking Hub | 68.3% | – |
| DTBench | Epoch AI Benchmarking Hub | 97.3% | – |
| Coding | |||
| SciCode | SciCode | 61.0% | – |
| FrontierCode | Cognition | 52.1%† | – |
| Arena Coding | Arena (LMArena) | 1517† | – |
| Arena WebDev | Arena (LMArena) | 1774† | – |
| LiveBench 2.0 Coding | LiveBench | 77.2%† | – |
| LiveBench 1.0 Coding | LiveBench | 91.4% | – |
| IOI | Vals AI | 83.1%† | – |
| Code Migration | Vals AI | 69.8%† | – |
Show all 115 benchmarks
| Metric | Publisher | Claude Sonnet 5.5 (max) | Kimi K3.1 Pro Together (max) |
|---|---|---|---|
| Coding | |||
| Code Migration v1.1 | Vals AI | 86.9%† | – |
| ProgramBench | Vals AI | 6.5%† | – |
| SWE-bench Multimodal | Vals AI | 58.3%† | – |
| Vibe Code Bench v1.1 | Vals AI | 92.4%† | – |
| CursorBench | Cursor | 55.5% | – |
| ALE-Bench | Epoch AI Benchmarking Hub | 1819.1† | – |
| FrontierSWE | Epoch AI Benchmarking Hub | 61.9% | – |
| Terminal-Bench 4.0 (AA) | Artificial Analysis | 63.6% | – |
| Startrise Frontend | Startrise | 75.9%† | – |
| GameBench 2 Overall | DuelLab GameBench 2 | 60.4† | – |
| GameBench 2 by reasoning setting | DuelLab GameBench 2 | 91.3† | – |
| Design Arena Website | Design Arena | 1315† | – |
| FrontierCode 1.1 (AA) | Artificial Analysis | 45.8% | – |
| FrontierCode 2.0 (AA) | Artificial Analysis | 41.7% | – |
| Agents & tools | |||
| Terminal-Bench | Terminal-Bench | 63.9% | – |
| APEX-Agents | Mercor | 75.5% | – |
| Arena Agent | Arena (LMArena) | 16 | – |
| LiveBench Long Agentic | LiveBench | 63.4%† | – |
| LiveBench Browser | LiveBench | 89.3%† | – |
| LiveBench Agentic Coding | LiveBench | 56.3% | – |
| Terminal-Bench 2.1 (Vals) | Vals AI | 83.2%† | – |
| GDPval-AA v2.1, normalised score | Artificial Analysis | 66.9% | – |
| GDPval-AA v2.1 | Artificial Analysis | 1838 | – |
| Analyst Agent (AA) | Artificial Analysis | 57.5% | – |
| CyberBench | Vals AI | 59.6%† | – |
| Finance Agent v2 | Vals AI | 58.1%† | – |
| Finance Agent v2.1 | Vals AI | 67.3%† | – |
| Harvey's Legal Agent Benchmark v1.1 | Vals AI | 10.4%† | – |
| Harvey's Legal Agent Benchmark v1 | Vals AI | 2.9%† | – |
| Legal Research Bench | Vals AI | 48.1%† | – |
| SREBench | Vals AI | 30.1%† | – |
| Tax Agent Bench | Vals AI | 42.0%† | – |
| Terminal-Bench 4.0 (Vals) | Vals AI | 64.1%† | – |
| Terminal-Bench Science | Vals AI | 47.1%† | – |
| Vending-Bench 2 | Andon Labs | 11165.3† | – |
| AutomationBench | Artificial Analysis | 71.8% | – |
| GDP.pdf (AA) | Artificial Analysis | 25.8% | – |
| Harvey LAB-AA v1.1 | Harvey | 2.8% | – |
| AA-Briefcase v1.1 | Artificial Analysis | 1813 | – |
| GDPx | GDPx by SemiAnalysis | 8.2% | – |
| Design Arena Agentic | Design Arena | 1283† | – |
| Terminal-Bench-Science 0.1 (AA) | Artificial Analysis | 53.3% | – |
| FACTS Search | 86.8%† | – | |
| Maths | |||
| FrontierMath Tiers 1–3 | Epoch AI Benchmarking Hub | 88.8% | 78.3% |
| FrontierMath Tier 4 | Epoch AI Benchmarking Hub | 80.5% | 65.8% |
| OTIS Mock AIME | Epoch AI Benchmarking Hub | 100.0% | 100.0% |
| ProofBench | Vals AI | 100.0% | – |
| LiveBench Mathematics | LiveBench | 96.1% | – |
| Arena Maths | Arena (LMArena) | 1489† | – |
| Knowledge | |||
| SimpleQA Verified | Epoch AI Benchmarking Hub | 46.5% | 62.2% |
| LiveBench 2.0 Data Analysis | LiveBench | 59.5%† | – |
| LiveBench Research | LiveBench | 88.0%† | – |
| LiveBench 1.0 Data Analysis | LiveBench | 59.5% | – |
| AA-Omniscience v1.1 | Artificial Analysis | 30.5 | – |
| BioMysteryBench | Vals AI | 81.1%† | – |
| ClaimBench | Vals AI | 100.0%† | – |
| Excel Modeling Benchmark | Vals AI | 75.7%† | – |
| Excel Modeling Benchmark v1.1 | Vals AI | 75.9%† | – |
| MedCode | Vals AI | 52.9%† | – |
| MedScribe | Vals AI | 91.1%† | – |
| Public Benefits Bench v1.1 | Vals AI | 67.2%† | – |
| GDP.pdf | Epoch AI Benchmarking Hub | 31.4% | – |
| AA-Omniscience v1.1: accuracy | Artificial Analysis | 51.5% | – |
| AA-Omniscience v1.1: non-hallucination | Artificial Analysis | 56.7% | – |
| HealthBench Professional (AA) | OpenAI | 63.0% | – |
| Instruction following | |||
| LiveBench Language | LiveBench | 78.0% | – |
| LiveBench Instruction Following | LiveBench | 56.8% | – |
| Arena Instruction Following | Arena (LMArena) | 1479† | – |
| Human preference | |||
| Arena Text | Arena (LMArena) | 1472† | – |
| Arena Creative Writing | Arena (LMArena) | 1465† | – |
| Arena Multi-turn | Arena (LMArena) | 1469† | – |
| Arena Longer Queries | Arena (LMArena) | 1489† | – |
| Multimodal | |||
| Arena Vision | Arena (LMArena) | 1284† | – |
| LiveBench Design | LiveBench | 81.3%† | – |
| SAGE | Vals AI | 88.0%† | – |
| Blueprint-Bench 2 | Epoch AI Benchmarking Hub | 39.3%† | – |
| Code2Video-AA | Artificial Analysis | 1443 | – |
| AA-3D | Artificial Analysis | 1204 | – |
| Long context | |||
| AA-LCR v1.1 | Artificial Analysis | 82.7% | – |
| MLCR | Artificial Analysis | 41.7% | – |
| Composite | |||
| Epoch Capabilities Index | Epoch AI Benchmarking Hub | 166.2† | – |
| LiveBench 2.0 | LiveBench | 77.0%† | – |
| LiveBench 1.0 | LiveBench | 75.7% | – |
| AA Intelligence Index v5.0 | Artificial Analysis | 54.5 | – |
| AA Intelligence Index v4.3.2 | Artificial Analysis | 56 | – |
| AA Progress Index v1 | Artificial Analysis | 350.5 | – |
| Vals Index | Vals AI | 70.8† | – |
| Vals Finance Index | Vals AI | 64.5%† | – |
| Vals Science Index | Vals AI | 59.1%† | – |
| Vals Router Index | Vals AI | 69.0%† | – |
Data as of 2026-11-09. Best configuration of each model; every score links to its source on the model pages.
DuelLab GameBench 2, release gb2-20261103-eaea31df94e6 (https://benchmarks.duellab.org/releases/gb2-20261103-eaea31df94e6/), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Scores mapped to BenchLeader model names; not endorsed by DuelLab.
What changed
- Claude Sonnet 5.5 (max): 2 score revisions.
- Kimi K3.1 Pro Together (max): first results.
- Claude Sonnet 5.5 (max): 1 score revision.
- Claude Sonnet 5.5 (max): 1 score revision.
- Claude Sonnet 5.5 (max): 1 score revision.
- Claude Sonnet 5.5 (max): 1 new result (MirrorCode).
- Claude Sonnet 5.5 (max): 5 new results (AA Intelligence Index v5.0, AA Progress Index v1, HLE-Diamond (AA)…); 3 score revisions; cost per task moved from $5.46/M to $10.02/M (83% up).
- Claude Sonnet 5.5 (max): 1 score revision.
- Claude Sonnet 5.5 (max): 1 new result (ARC-AGI-1); 1 score revision.
- Claude Sonnet 5.5 (max): 2 new results (LMCA, DTBench).
Related comparisons
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- Claude Sonnet 5.5 vs Claude Opus 5.5
- Claude Sonnet 5.5 vs Gemini 4 Carbon
- Kimi K3.1 Pro Together vs Claude Fable 5.2
- Kimi K3.1 Pro Together vs Claude Opus 5.5
- Kimi K3.1 Pro Together vs Gemini 4 Carbon
- Kimi K3.1 Pro Together vs GPT-6 Astra
- Claude Sonnet 5.5 vs Kimi K3
Rankings: Best LLM overall · Best LLM for coding · Best LLM for agents · Best cheap LLMs
Claude Sonnet 5.5 vs Kimi K3.1 Pro Together: questions
- Is Claude Sonnet 5.5 better than Kimi K3.1 Pro Together?
- Claude Sonnet 5.5 (max) leads on quality: 65.0 vs 60.5. The BenchLeader Index combines every independent quality benchmark; Claude Sonnet 5.5 (max) is ahead overall as of 9 Nov 2026, but check the category scores for your use.
- Do independent benchmarks agree on Claude Sonnet 5.5 vs Kimi K3.1 Pro Together?
- Across the 7 benchmarks both have, Claude Sonnet 5.5 leads 5, Kimi K3.1 Pro Together leads 1 and 1 is a tie. Every overall index that rates both puts Claude Sonnet 5.5 ahead.
- When was Kimi K3.1 Pro Together released?
- Kimi K3.1 Pro Together was released on 23 Oct 2026.