Comprehensive side-by-side LLM comparison
. Both models have their strengths depending on your specific coding needs.
OpenAI
GPT-5.3 Codex, released by OpenAI in February 2026, is a coding-specialized large language model from the GPT-5.3 family. It targets software engineering workflows including automated code generation, test writing, and agentic multi-file editing, built on the incremental improvements of the GPT-5.3 generation.
Moonshot AI
Kimi K2, released by Moonshot AI on July 11, 2025, is an open-weight Mixture-of-Experts large language model with 1 trillion total parameters and 32 billion active parameters per inference. It features a 256K token context window (expanded from 128K in an September 2025 update) and demonstrated strong performance on agentic coding benchmarks. Kimi K2 targets software engineering agents, tool-use workflows, and open-source deployments under a modified MIT license.
6 months newer
Kimi K2
Moonshot AI
2025-07-11

GPT-5.3 Codex
OpenAI
2026-02
Context window and performance specifications
Available providers and their performance metrics
GPT-5.3 Codex
Kimi K2
Moonshot AI
GPT-5.3 Codex
Kimi K2
GPT-5.3 Codex
Kimi K2