Claude Sonnet 4.5 vs GPT-4o (Omni)
Compare Claude Sonnet 4.5 by Anthropic against GPT-4o (Omni) by OpenAI, context windows of 200K vs 128K, tested across 43 shared challenges. Updated May 2026.
Which is better, Claude Sonnet 4.5 or GPT-4o (Omni)?
Claude Sonnet 4.5 and GPT-4o (Omni) are both competitive models. Claude Sonnet 4.5 costs $3/M input tokens vs $2.5/M for GPT-4o (Omni). Context windows: 200K vs 128K tokens. Compare their real outputs side by side below.
Key Differences Between Claude Sonnet 4.5 and GPT-4o (Omni)
Claude Sonnet 4.5 is made by anthropic while GPT-4o (Omni) is from openai. Claude Sonnet 4.5 has a 200K token context window compared to GPT-4o (Omni)'s 128K. On pricing, Claude Sonnet 4.5 costs $3/M input tokens vs $2.5/M for GPT-4o (Omni).
Per 1M tokens
GPT-4o (Omni) is cheaper on both — 1.2× input, 1.5× output
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Style Comparison
Claude Sonnet 4.5 uses 18.0x more emoji
