Claude Sonnet 4.5 vs Muse Spark
Anthropic Claude Sonnet 4.5 | Meta Muse Spark | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Meta |
| Release date | Sep 29 2025 | Apr 8 2026 |
| Access | Proprietary | Proprietary |
| 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. | 79% | — |
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. | — | 55% |
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. | 77.2% | 77.4%Best |
Agentic coding DeepSWE 1.1Artificial Analysis' independent test of deep, agentic software-engineering work — the AI has to plan and carry out substantial coding tasks end to end. (Version 1.1 of the test.) Higher is better. | — | 10% |
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. | 50% | — |
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. | — | 67.3% |
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. | — | 82.2% |
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. | — | 17% |
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. | — | 49.4% |
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. | — | 50.4% |
Abstract reasoning ARC-AGI-2Puzzle-style tests of abstract reasoning and pattern-finding — the kind of thing people find easy but AIs often struggle with. Higher is better. | — | 42.5% |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 83.4% | 89.5%Best |
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. | — | 53.3% |
Chart reasoning CharXiv ReasoningCan the AI read and reason about complex charts and figures, not just text? Higher is better. | — | 88.9% |
Visual reasoning BabyVisionTests core visual reasoning — seeing and understanding images the way even young children can, which AIs often find surprisingly hard. Higher is better. | — | 39.9% |
Multimodal MMMUTests the AI on understanding images and text together across many college subjects. Higher is better. | 68% | 80.4%Best |
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. | — | 1488 |
| Timeline | ||
| Release gap | Claude Sonnet 4.5 shipped 191 days before Muse Spark | |
Which is better: Claude Sonnet 4.5 or Muse Spark?
Muse Spark leads Claude Sonnet 4.5 on 3 of the 3 benchmarks they both report (SWE-Bench Verified, GPQA Diamond, MMMU). Claude Sonnet 4.5 shipped 191 days before Muse Spark, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
On SWE-Bench Verified, Muse Spark leads at 77.4% vs Claude Sonnet 4.5 at 77.2%. On GPQA Diamond, Muse Spark leads at 89.5% vs Claude Sonnet 4.5 at 83.4%. On MMMU, Muse Spark leads at 80.4% vs Claude Sonnet 4.5 at 68%.
Frequently asked questions
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
Muse Spark was released by Meta on Apr 8 2026.
Muse Spark leads on SWE-Bench Verified — Claude Sonnet 4.5 77.2% vs Muse Spark 77.4%.
Muse Spark leads on GPQA Diamond — Claude Sonnet 4.5 83.4% vs Muse Spark 89.5%.
Other comparisons
Claude Sonnet 4.5 vs GPT-5.6 SolMuse Spark vs GPT-5.6 SolClaude Sonnet 4.5 vs Gemini OmniMuse Spark vs Gemini OmniClaude Sonnet 4.5 vs Grok 4.5Muse Spark vs Grok 4.5Claude Sonnet 4.5 vs DeepSeek-V4-ProMuse Spark vs DeepSeek-V4-ProClaude Sonnet 4.5 vs Mistral Medium 3.5Muse Spark vs Mistral Medium 3.5Claude Sonnet 4.5 vs Kimi K2.7 CodeMuse Spark vs Kimi K2.7 Code