GPT-5 vs GPT-5.3-Codex
Compare GPT-5 and GPT-5.3-Codex, both from OpenAI, context windows of 400K vs 400K, tested across 51 shared challenges. Updated April 2026.
Which is better, GPT-5 or GPT-5.3-Codex?
GPT-5 and GPT-5.3-Codex are both competitive models. GPT-5 costs $1.25/M input tokens vs $1.75/M for GPT-5.3-Codex. Context windows: 400K vs 400K tokens. Compare their real outputs side by side below.
Key Differences Between GPT-5 and GPT-5.3-Codex
GPT-5 is made by openai while GPT-5.3-Codex is from openai. GPT-5 has a 400K token context window compared to GPT-5.3-Codex's 400K. On pricing, GPT-5 costs $1.25/M input tokens vs $1.75/M for GPT-5.3-Codex.
No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.
Style Comparison
GPT-5.3-Codex uses 15.8x more emoji
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.
