Which AI Should I Use for Coding?

Coding with AI changed when models stopped only writing snippets and started working inside real projects.

The choice is now about workflow: local agent, cloud agent, code review, learning assistant, terminal loop, or broad product thinking.

Quick picks

Best local agent workflow: Claude Code or Codex CLI. Use a terminal agent when you want file access, tests, diffs, and close steering.
Best review workflow: Codex review prompts. Use Codex to inspect a diff for bugs, regressions, test gaps, and unclear behavior.
Best learning assistant: ChatGPT or Claude. Use a chat assistant to explain code, teach concepts, and reason through errors.
Best Google ecosystem option: Gemini and Gemini CLI. Use when your workflow already leans into Google tooling and Gemini features.

Use an agent when there is a repo

If the task depends on existing files, tests, routes, build tools, styles, or hidden project conventions, use a coding agent that can inspect the workspace. Snippet-only chat is weaker because it cannot see the system.

The best agent sessions start with reading and planning before editing.

Use chat when you are learning

If you are trying to understand an error, learn a concept, compare libraries, or sketch an approach, a normal chat assistant is often enough. Paste the error, the relevant function, and what you expected to happen.

For beginners, the most powerful coding prompt is not "write this." It is "explain this like I am learning and ask me one question before fixing it."

Use reviews as a separate step

After the agent writes code, ask for review. Make it look for bugs, missing tests, security issues, accessibility, performance, and deployment risk.

This habit catches more than asking the same session "anything else?"

Copyable prompts

Coding tool chooser prompt

I need help with this coding task: [TASK]. Project context: [CONTEXT]. Tell me whether I should use a chat assistant, a local coding agent, a cloud agent, or a code review workflow. Explain the reason and the safest first prompt.

Agent first prompt

Before editing, inspect the project. Identify relevant files, commands, tests, risks, and the smallest safe change for this goal: [GOAL]. Then wait for approval before editing.

Review prompt

Review this coding change. Findings first. Prioritize bugs, regressions, missing tests, security/privacy issues, accessibility, and unclear behavior. Then summarize residual risk.

Related Power of AI pages

AI Coding Agents: The full coding-agent overview.
Codex Best Practices: Use Codex with repo context and verification.
Claude Code Best Practices: Use Claude Code safely and effectively.
Claude Code vs Codex: Choose between the two workflows.
How to Use Codex for Code Review: Make AI review concrete.

Sources and official references

Related Power of AI pages

Keep reading with AI Finder, Prompt Studio, ChatGPT vs Claude vs Gemini, the AI glossary, and Which AI Should You Use?.