Claude Sonnet 4.5 vs Muse Spark

Claude Sonnet 4.5 and Muse Spark are both large language models tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Claude Sonnet 4.5

Claude Sonnet 4.5 is a large language model from Anthropic with particular strengths in software coding, agentic tasks where it runs in a loop and uses tools, and in using computers. The model maintains focus for more than 30 hours on complex, multi-step tasks. Pricing remains the same as Claude Sonnet 4, at $3/$15 per million tokens. It is the most aligned frontier model Anthropic has released, showing large improvements across several areas of alignment compared to previous Claude models.

Muse Spark

A natively multimodal reasoning model with support for tool-use, visual chain of thought, and multi-agent orchestration developed by Meta Superintelligence Labs.

Attribute	Claude Sonnet 4.5	Muse Spark
Pricing	Paid	Paid
Price	$3 per million input tokens, $15 per million output tokens	Free (consumer), API pricing TBD
Free trial	No	No
Open source	No	No
Has API	Yes	Yes
Self-hosted option	No	No
Platforms	Claude API (claude-sonnet-4-5), Claude.ai web interface, iOS and Android apps, Amazon Bedrock, Google Cloud Vertex AI	Meta AI app, meta.ai website, and rolling out to WhatsApp, Instagram, Facebook, Messenger, and Meta AI glasses in coming weeks
Languages	Supports input and output in multiple languages	—
Released	2025-09-29	2026-04-08
Pros	State-of-the-art on SWE-bench Verified evaluation for software coding abilities. Significant leap forward on computer use, leading at 61.4% on OSWorld benchmark. Most aligned frontier model with reduced concerning behaviors like sycophancy, deception, and power-seeking. Can maintain focus for more than 30 hours on complex multi-step tasks.	Completely free access through meta.ai and Meta AI app Improved training techniques enable comparable performance to older Llama 4 with an order of magnitude less compute Contemplating mode orchestrates multiple agents in parallel, competing with extreme reasoning modes of frontier models Strong performance on medical and scientific benchmarks, including CharXiv, HealthBench Hard, and FrontierScience
Cons	Context window limited to 200K tokens; 1M context beta was deprecated by Anthropic on April 30th 2026. Maximum output capacity of 64K tokens is lower than some competing models.	Meta acknowledged gaps in multi-step agent tasks and coding workflows, with weak performance on Terminal-Bench 2.0 No public API; private preview is only available to select enterprise partners with no confirmed broader access date Proprietary model with no weights available and no fine-tuning access, marking a departure from Meta's open-source Llama legacy

Bottom line

Claude Sonnet 4.5 and Muse Spark are closely matched on pricing model, openness, and API availability — pick by feature set and platform support in the table above.

Comparison data is sourced and verified by the AIDiveForge data pipeline. AIDiveForge is editorially independent.