Claude 3 Sonnet vs GPT-5.1-Codex
Compare Claude 3 Sonnet by Anthropic against GPT-5.1-Codex by OpenAI, tested across 13 shared challenges. Updated April 2026.
Which is better, Claude 3 Sonnet or GPT-5.1-Codex?
Claude 3 Sonnet and GPT-5.1-Codex are both competitive models. Claude 3 Sonnet costs $3/M input tokens vs $1.25/M for GPT-5.1-Codex. Compare their real outputs side by side below.
Key Differences Between Claude 3 Sonnet and GPT-5.1-Codex
Claude 3 Sonnet is made by anthropic while GPT-5.1-Codex is from openai. On pricing, Claude 3 Sonnet costs $3/M input tokens vs $1.25/M for GPT-5.1-Codex.
No community votes yet. On paper, GPT-5.1-Codex has the edge — bigger model tier, newer, bigger context window.
Style Comparison
GPT-5.1-Codex uses 343.9x more bold
vsAsk them anything yourself
Some models write identically. You are paying for the brand.
178 models fingerprinted across 32 writing dimensions. Free research.
185x
price gap between models that write identically
178
models
12
clone pairs
32
dimensions
279 AI models invented the same fake scientist.
We read every word. 250 models. 2.14 million words. This is what we found.
