QUICK VERDICT — AUGUST 2026
● SWE Marathon: Kimi Code (K3) — 42.0% #1. Codex (GPT-5.6) — Terminal-Bench 88.8% #1.
● Workflow model: Kimi Code — interactive CLI/IDE sessions. Codex — async background tasks, returns a PR.
● Price: Kimi Code from Moderato $19/mo. Codex included with ChatGPT Plus $20/mo.
● Async execution: Codex only — assign a task and come back to a completed PR.
● Credit pool: Kimi Code — shared with chat (heavy chat reduces coding headroom).
● Hallucination (Kimi K3): 51% in independent testing — validate on your tasks.
● Regulatory risk: Kimi Code — Moonshot sanctions warning. Codex — none.
● Benchmark source: Different benchmarks — not directly comparable head-to-head.
Kimi Code and OpenAI Codex have different workflow models that make them non-substitutes for many use cases. Kimi Code is an interactive coding agent — you work with it in a CLI or IDE session, providing context and direction as it codes. OpenAI Codex is an async agent — you assign a task, Codex executes it in a persistent cloud session in the background, and delivers a completed PR for your review. If you need to be in the loop during execution, Kimi Code. If you want to assign and return, Codex.
The benchmark comparison is complicated by the fact that Kimi K3's strongest result is SWE Marathon (42.0%, #1 globally) while GPT-5.6's strongest result is Terminal-Bench (88.8%, #1 before DeepSeek V4 Flash). These are different benchmarks measuring different aspects of coding performance. SWE Marathon tests long-horizon multi-file repository tasks. Terminal-Bench tests terminal execution and agentic task completion. Both are legitimate measures — they are just answering different questions about what "best coding model" means.
Kimi Code for: Interactive coding sessions where long-horizon multi-file SWE Marathon performance is the key metric. Available from Moderato at $19/month. Watch the shared credit pool — heavy chat reduces Kimi Code headroom. Validate 51% hallucination rate on your specific task type. Verify Moonshot regulatory status before enterprise deployment.
OpenAI Codex for: Async task execution where you assign a coding task and return to a completed PR. Included with ChatGPT Plus at $20/month. Terminal-Bench 88.8%. Persistent cloud sessions via the Ona acquisition. No regulatory risk. Best for teams with a well-defined backlog of discrete coding tasks that can run in the background.
Last updated August 6, 2026. Related: Kimi vs Claude Code vs Codex three-way → · Kimi Code vs Claude Code →