Claude Opus 5vsMuse Spark 1.2

Claude Opus 5
Muse Spark 1.2
Specifications
Context window
1M
1M
Benchmarks
Nonsense detection
BullshitBench v2
73%
Prompt injection robustness
Gray Swan IPI · k = 1
0.2%
Prompt injection robustness
Gray Swan IPI · k = 10
1.6%
Prompt injection robustness
Gray Swan IPI · k = 15
2%
Agentic coding
CursorBench v3.2
70%
Agentic coding
DeepSWE 1.1
68.8%Best
59.3%
Agentic coding
FrontierCode v1.1 (Main)
53.4%
Supabase coding
Supabase Evals · with skills
94.7%
Supabase coding
Supabase Evals · no skills
94.7%
Agentic computer work
Frontier-Bench v0.1
43.3%
Agentic terminal coding
Terminal-Bench 2.1
82.9%
Web browsing
BrowseComp
90.8%
Multidisciplinary reasoning
Humanity's Last Exam · no tools
56.3%
Multidisciplinary reasoning
Humanity's Last Exam · with tools
64.7%
Novel problem-solving
ARC-AGI-3
30.2%
Biology
BioMysteryBench · hard
49.4%
Biology
BioMysteryBench · human solved
90.1%
Agentic computer use
OSWorld 2.0
70.6%
Business workflows
AutomationBench
26%
Agentic legal work
Harvey's Legal Agent Benchmark (Held-out)
11.7%
Health
HealthBench Professional
59.8%
Knowledge work
GDPval-AA v2
1861
Community preference
Arena Elo (Text)
1495
Community preference (code)
Arena Elo (Code)
1673
Overview
CompanyAnthropicMeta
Release dateJul 24 2026Aug 5 2026
AccessProprietaryProprietary

Which is better: Claude Opus 5 or Muse Spark 1.2?

Claude Opus 5 leads Muse Spark 1.2 on 1 of the 1 benchmark they both report (DeepSWE 1.1). Claude Opus 5 shipped 12 days before Muse Spark 1.2, so benchmark comparisons should account for the intervening progress.

Context windows are 1M (Claude Opus 5) vs 1M (Muse Spark 1.2).

On DeepSWE 1.1, Claude Opus 5 leads at 68.8% vs Muse Spark 1.2 at 59.3%.

Frequently asked questions

Claude Opus 5 was released by Anthropic on Jul 24 2026.

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

Claude Opus 5 leads on DeepSWE 1.1 — Claude Opus 5 68.8% vs Muse Spark 1.2 59.3%.

Claude Opus 5 has a 1M context window; Muse Spark 1.2 has 1M.

Other comparisons