Claude Opus 4.5 vs GPT-5

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

Arena Elo
1440
Context
200K
GPQA
87%
SWE-Bench
80%
Input $/1M
$5
Output $/1M
$25
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

Claude Opus 4.5 and GPT-5 are both high-performance proprietary language models with similar core capabilities in reasoning, coding, and natural language generation. The key differences lie in context window size, pricing, and safety focus. GPT-5 offers double the context capacity (400k vs 200k tokens) at roughly one-fifth the input cost and less than half the output cost. GPT-5 also holds a slight edge in Arena Elo (1450 vs 1440). Claude Opus 4.5 emphasizes safety and alignment, with particular strength in maintaining coherence over extended multi-turn conversations. Choose Claude Opus 4.5 if safety, alignment, and consistent multi-turn dialogue quality are priorities, or if you prefer Anthropic's approach to responsible AI development. Choose GPT-5 if you need maximum context window, lower costs, or prefer OpenAI's ecosystem and integration options.

Claude Opus 4.5 vs GPT-5 — FAQ

Not universally. GPT-5 has a slight edge in Arena Elo (1450 vs 1440), double the context window, and lower pricing. Claude Opus 4.5 emphasizes safety and alignment, which may be preferable for applications requiring careful output control.