Comprehensive side-by-side LLM comparison
Claude Opus 4.5 leads with 33.3% higher average benchmark score. Grok 3 offers 752.4K more tokens in context window than Claude Opus 4.5. Grok 3 is $12.00 cheaper per million tokens. Claude Opus 4.5 is available on 3 providers. Overall, Claude Opus 4.5 is the stronger choice for coding tasks.
Anthropic
Claude Opus 4.5, released by Anthropic in November 2025, is a large language model from the Claude 4.5 family built for demanding reasoning tasks, advanced code generation, and complex agentic workflows. It features a 200K token context window, 64K maximum output tokens, native image understanding, and extended thinking with configurable effort levels. Opus 4.5 targets deep analytical work, multi-step tool orchestration, and applications requiring sustained reasoning across long, complex tasks.
xAI
Grok 3, released by xAI in February 2025, is a large language model trained on xAI's Colossus supercluster with substantially increased compute over previous generations. It features a 1M token context window, RL-enhanced Think mode for extended reasoning, and demonstrated strong results on mathematics, coding, and scientific benchmarks. Grok 3 targets complex reasoning, real-time information tasks via X platform integration, and agentic workflows via the xAI API.
8 months newer

Grok 3
xAI
2025-02-17

Claude Opus 4.5
Anthropic
2025-11-01
Cost per million tokens (USD)
Claude Opus 4.5
Grok 3
Context window and performance specifications
Average performance across 2 common benchmarks
Claude Opus 4.5
Grok 3
Performance comparison across key benchmark categories
Claude Opus 4.5
Grok 3
Claude Opus 4.5
2025-05
Available providers and their performance metrics
Claude Opus 4.5
Anthropic
AWS Bedrock
Google Cloud Vertex AI
Grok 3
Claude Opus 4.5
Grok 3
Claude Opus 4.5
Grok 3
xAI