Comprehensive side-by-side LLM comparison
Claude Sonnet 4.5 leads with 47.7% higher average benchmark score. Claude Sonnet 4.5 offers 198.5K more tokens in context window than GPT-4. Claude Sonnet 4.5 is $72.00 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-4 was created as a large multimodal model capable of accepting image and text inputs while producing text outputs. Developed to exhibit human-level performance on various professional and academic benchmarks, it marked a significant advancement in reliability, creativity, and handling of nuanced instructions compared to its predecessors.
2 years newer

GPT-4
OpenAI
2023-06-13

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

Claude Sonnet 4.5

GPT-4
Context window and performance specifications
Average performance across 1 common benchmarks

Claude Sonnet 4.5

GPT-4
GPT-4
2022-12-31
Claude Sonnet 4.5
2025-01-31
Available providers and their performance metrics

Claude Sonnet 4.5
Anthropic
ZeroEval


Claude Sonnet 4.5

GPT-4

Claude Sonnet 4.5

GPT-4
GPT-4
Azure
OpenAI