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Model launch

OpenAI releases GPT-5.3-Codex

GPT-5.3-Codex is OpenAI’s most advanced agentic coding model, combining the frontier software engineering performance of GPT-5.2-Codex with the broader reasoning and professional knowledge capabilities of GPT-5.2. It ach

Type
MODEL_LAUNCH
Detection
benchmark
Confidence
high
Status

Primary source

Epoch AI Benchmarking Hub · epoch.ai/benchmarks/eci ↗

Independent benchmark runs (GPQA Diamond, SWE-bench Verified, FrontierMath, ...) plus externally reported leaderboards and the Epoch Capabilities Index (ECI).