Claude Sonnet 4.5vsMuse Spark 1.2

Claude Sonnet 4.5
Muse Spark 1.2
Specifications
Context window
1M
Benchmarks
Nonsense detection
BullshitBench v2
79%
Coding
SWE-Bench Verified
77.2%
Agentic coding
DeepSWE 1.1
59.3%
Next.js coding
Next.js Evals
50%
Agentic terminal coding
Terminal-Bench 2.1
82.9%
Science
GPQA Diamond
83.4%
Multimodal
MMMU
68%
Overview
CompanyAnthropicMeta
Release dateSep 29 2025Aug 5 2026
AccessProprietaryProprietary

Which is better: Claude Sonnet 4.5 or Muse Spark 1.2?

Claude Sonnet 4.5 and Muse Spark 1.2 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude Sonnet 4.5 shipped 310 days before Muse Spark 1.2, 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.

Direct benchmark comparisons are unavailable — Claude Sonnet 4.5 and Muse Spark 1.2 don't publish scores on any of the same benchmarks.

Frequently asked questions

Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.

Muse Spark 1.2 was released by Meta on Aug 5 2026.

Other comparisons