Claude Sonnet 4.5 vs GPT-5

Benchmark, pricing and capability comparison of Claude Sonnet 4.5 and GPT-5.

Arena Elo
1415
Context
200K
GPQA
83%
SWE-Bench
77%
Input $/1M
$3
Output $/1M
$15
Full details
OpenAI
GPT-5

OpenAI

Arena Elo
1450
Context
400K
GPQA
85%
SWE-Bench
75%
Input $/1M
$1.25
Output $/1M
$10
Full details

Verdict

GPT-5 and Claude Sonnet 4.5 are both proprietary large language models with strong capabilities in reasoning, coding, and natural language tasks. The key differences lie in performance metrics and pricing: GPT-5 scores slightly higher on Arena Elo (1450 vs 1415), offers double the context window (400,000 vs 200,000 tokens), and is significantly cheaper at $1.25 input/$10 output per 1M tokens compared to Claude's $3/$15. Both models excel at multi-turn conversations, content generation, and technical tasks. Choose Claude Sonnet 4.5 if you prioritize working with an Anthropic model ecosystem, need strong reasoning for enterprise applications, or prefer the specific strengths of Claude's training approach for tasks like detailed analysis or nuanced writing. Choose GPT-5 if you need the larger context window for processing very long documents, want the lower cost structure for high-volume applications, or prefer OpenAI's integration ecosystem and the slight edge in benchmark performance.

Claude Sonnet 4.5 vs GPT-5 — FAQ

GPT-5 has a slight edge in Arena Elo benchmarks (1450 vs 1415) and offers double the context window at a lower price point. However, "better" depends on use case—Claude may excel in certain reasoning or enterprise scenarios, while GPT-5 leads on raw performance and cost efficiency.