Claude Fable 5 vs Kimi K3
Anthropic Claude Fable 5 | Moonshot AI Kimi K3 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Moonshot AI |
| Release date | Jun 9 2026 | Jul 16 2026 |
| Access | Proprietary | Open Weight |
| Specifications | ||
Parameters | — | 2.8T |
Context window | 1M | 1M |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | 56% | — |
Agentic coding SWE-Bench ProCan the AI fix real bugs in real software? It's handed actual problems from open-source projects and has to write code that genuinely solves them. Higher is better. | 80.3% | — |
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 95.5% | — |
Agentic coding CursorBench v3.1Cursor's own test of harder, real-world coding tasks inside a code editor. Higher is better. | 72.9% | — |
Agentic coding DeepSWE 1.0Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. Higher is better. | 66.1% | 67.5%Best |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | 92% | — |
Agentic terminal coding Terminal-Bench 2.1Can the AI work in a command-line terminal — running commands and finishing technical setup tasks the way a developer would? Higher is better. | 88% | 88.3%Best |
Multi-step tool use MCP AtlasCan the AI chain together many tools and steps to complete one bigger task, rather than doing just a single thing? Higher is better. | — | 84.2% |
Professional tool use JobBenchTests the AI on professional workplace tasks that require using real work tools — the kind of multi-step jobs an office worker handles. Higher is better. | — | 52.9% |
Personal tool use Toolathlon-VerifiedTests how well the AI uses everyday personal tools and apps to get things done — a human-checked version of Toolathlon. Higher is better. | — | 73.2% |
Web browsing BrowseCompCan the AI browse the web and track down hard-to-find answers? Higher is better. | 86.9% | 91.2%Best |
Multidisciplinary reasoning Humanity's Last Exam · no toolsHumanity's Last Exam — extremely hard expert questions across many subjects, written so you can't just look up the answer. “No tools” means the AI answers on its own. Higher is better. | — | 43.5% |
Multidisciplinary reasoning Humanity's Last Exam · with toolsHumanity's Last Exam — extremely hard expert questions across many subjects. “With tools” means the AI is allowed to search the web or run code while answering. Higher is better. | 64.5%Best | 56% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 93.5% |
Agentic computer use OSWorld-VerifiedCan the AI actually operate a computer — clicking, typing, and using real apps — to finish tasks on its own? Higher is better. | 85% | — |
Agentic legal work Harvey's Legal Agent BenchmarkHarvey's test of whether an AI agent can complete real legal work — drafting and reviewing documents, working with spreadsheets and presentations, and navigating files the way a lawyer's assistant would. Higher is better. | 11.25% | — |
Tax questions TaxEval v2A set of real tax questions created by Vals AI — can the AI give accurate answers about tax rules and filings? Higher is better. | 76.94% | — |
Medical admin work MedScribeCan the AI support doctors with their administrative work, like notes and paperwork? Created by Vals AI. Higher is better. | 88.52% | — |
Knowledge work GDPval-AAMeasures how well the AI does economically valuable knowledge work, judged against human experts. Shown as a rating (like a chess Elo) — higher is better. | 1932 | — |
Knowledge work GDPval-AA v2economically valuable knowledge work (v2, re-based Elo) | 1760Best | 1668 |
Chart reasoning CharXiv ReasoningCan the AI read and reason about complex charts and figures, not just text? Higher is better. | — | 84.8% |
Multimodal reasoning MMMU-ProA tougher version of MMMU — college-level questions that mix images, diagrams, and text together. Higher is better. | — | 81.6% |
Community preference Arena Elo (Text)Real people chat with two anonymous AIs side by side and vote for the answer they prefer. Votes become a chess-style Elo rating on arena.ai — it measures which AI people actually like, not test scores. Higher is better. | 1509 | — |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | 1649 | — |
| Timeline | ||
| Release gap | Claude Fable 5 shipped 37 days before Kimi K3 | |
Which is better: Claude Fable 5 or Kimi K3?
Kimi K3 leads Claude Fable 5 on 3 of the 5 benchmarks they both report. Claude Fable 5 shipped 37 days before Kimi K3, so benchmark comparisons should account for the intervening progress.
Context windows are 1M (Claude Fable 5) vs 1M (Kimi K3). Claude Fable 5 is proprietary, while Kimi K3 is open weight.
On DeepSWE 1.0, Kimi K3 leads at 67.5% vs Claude Fable 5 at 66.1%. On Terminal-Bench 2.1, Kimi K3 leads at 88.3% vs Claude Fable 5 at 88%. On BrowseComp, Kimi K3 leads at 91.2% vs Claude Fable 5 at 86.9%. On Humanity's Last Exam · with tools, Claude Fable 5 leads at 64.5% vs Kimi K3 at 56%. On GDPval-AA v2, Claude Fable 5 leads at 1760 vs Kimi K3 at 1668.
Frequently asked questions
Claude Fable 5 was released by Anthropic on Jun 9 2026.
Kimi K3 was released by Moonshot AI on Jul 16 2026.
Kimi K3 leads on DeepSWE 1.0 — Claude Fable 5 66.1% vs Kimi K3 67.5%.
Claude Fable 5 leads on Humanity's Last Exam · with tools — Claude Fable 5 64.5% vs Kimi K3 56%.
Claude Fable 5 has a 1M context window; Kimi K3 has 1M.
Claude Fable 5 is a proprietary model released by Anthropic. Kimi K3 is an open weight model released by Moonshot AI.
Other comparisons
Claude Fable 5 vs GPT-5.6 SolKimi K3 vs GPT-5.6 SolClaude Fable 5 vs Gemini 3.5 FlashKimi K3 vs Gemini 3.5 FlashClaude Fable 5 vs Muse Spark 1.1Kimi K3 vs Muse Spark 1.1Claude Fable 5 vs Grok 4.5Kimi K3 vs Grok 4.5Claude Fable 5 vs DeepSeek-V4-ProKimi K3 vs DeepSeek-V4-ProClaude Fable 5 vs Mistral Medium 3.5Kimi K3 vs Mistral Medium 3.5