Coding is the most contested category, and it's genuinely use-case dependent. Claude is widely favored for agentic coding, large-codebase reasoning, and careful multi-file edits, helped by very large context windows. OpenAI ships a coding-tuned model (gpt-5.3-codex) and ChatGPT remains excellent for explanations, snippets, and debugging. Both are strong; the right pick often comes down to which tooling you already use.
Three practical factors matter more than any leaderboard. Context window: pasting a large codebase or long logs favors models with bigger windows (Claude's 1M-token context on recent models, for example). Tooling: whether the assistant can run, edit files, and use tools in your environment changes the experience more than raw model quality. Cost: code generation can be token-heavy, so the per-token API prices below matter if you're building on the API rather than using a flat-fee app.
Gemini is a credible third option, especially for code that touches Google Cloud or Android. For composing strong coding prompts regardless of model, see our Code Prompt Builder and best prompts for coding.
**Bottom line:** Claude for agentic, large-context, multi-file work; ChatGPT (incl. the codex model) for fast snippets, debugging, and explanation; pick by tooling fit, not a single score.
Pick Claude for coding when: you're doing multi-file edits, reasoning over a large codebase, or want long-context agentic behavior.
Pick ChatGPT for coding when: you want fast snippets, debugging help, explanations, or the dedicated codex model and its surrounding tooling.