Comprehensive side-by-side LLM comparison
Claude Sonnet 4.5 leads with 7.0% higher average benchmark score. GPT-5 nano offers 264.0K more tokens in context window than Claude Sonnet 4.5. GPT-5 nano is $17.55 cheaper per million tokens. Overall, Claude Sonnet 4.5 is the stronger choice for coding tasks.
Anthropic
Claude Sonnet 4.5 was developed to bridge human thinking and machine assistance, allowing people to work with language and tools in a more conversational and natural way. Built with a focus on turning ideas into results, it represents an evolution in making AI feel less mechanical while maintaining strong capabilities across reasoning, coding, and collaborative tasks.
OpenAI
GPT-5 Nano was developed as the most compact variant in the GPT-5 family, designed for deployment in resource-constrained environments and edge computing scenarios. Built to bring next-generation AI capabilities to devices and applications where latency and efficiency are paramount, it distills GPT-5 innovations into a minimal footprint.
1 month newer

GPT-5 nano
OpenAI
2025-08-07

Claude Sonnet 4.5
Anthropic
2025-09-29
Cost per million tokens (USD)

Claude Sonnet 4.5

GPT-5 nano
Context window and performance specifications
Average performance across 2 common benchmarks

Claude Sonnet 4.5

GPT-5 nano
GPT-5 nano
2024-05-30
Claude Sonnet 4.5
2025-01-31
Available providers and their performance metrics

Claude Sonnet 4.5
Anthropic
ZeroEval


Claude Sonnet 4.5

GPT-5 nano

Claude Sonnet 4.5

GPT-5 nano
GPT-5 nano
OpenAI
ZeroEval