Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
OpenAI
GPT-5 Codex, released by OpenAI in August 2025, is a coding-specialized large language model from the GPT-5 family engineered for software engineering, code generation, and agentic development workflows. It builds on GPT-5's architecture with optimizations targeting multi-file code editing, test generation, and automated debugging. GPT-5 Codex targets developers and agentic coding tools requiring a model tuned specifically for programming tasks.
xAI
Grok 3 mini, released by xAI alongside Grok 3 in February 2025, is a compact reasoning model from the Grok 3 family featuring RL-enhanced Think mode for extended chain-of-thought processing. It features a 131K token context window and targets STEM tasks, mathematics, and coding applications where cost-efficient reasoning with configurable depth is required.
5 months newer

Grok 3 mini
xAI
2025-02-17

GPT-5 Codex
OpenAI
2025-08
Context window and performance specifications
Available providers and their performance metrics
GPT-5 Codex
Grok 3 mini
xAI
GPT-5 Codex
Grok 3 mini
GPT-5 Codex
Grok 3 mini