When to Use What

By the end of this lesson, you will be able to look at most common tasks and confidently choose whether to reach for browser chat, a CLI tool, or both.

Why this matters

In the previous lesson, you learned what browser chat does well. But you also learned what it cannot do — directly access your local files, run code in your environment, or make changes to a project. That is where CLI tools come in.

Knowing which tool to use for which job is the core orchestration skill of this entire course. Get this right, and every module after this one becomes easier.

Two tools, two superpowers

You already know browser chat. Here is its counterpart:

Browser chat (ChatGPT, Claude.ai, Gemini):

• Runs in your web browser
• You type messages, it responds
• Great for conversations, questions, brainstorming, writing
• Cannot directly access or modify local files on your computer (unless you explicitly upload or connect them)

CLI tools (Claude Code, Gemini CLI, Codex CLI, GitHub Copilot CLI):

• Run in your terminal
• Have access to your project files
• Can create, edit, and delete files
• Can run commands, tests, and builds
• Designed for multi-step building tasks

Think of it as advisors vs. builders. Browser chat is an advisor — great for conversations and ideas. Builders can live in your terminal (CLI tools) or in your browser (Claude Code web, Codespaces, code interpreters). The key question is not “browser or terminal?” — it is “am I thinking or building?”

The decision guide

Not sure which to use? Walk through this interactive flowchart:

If the flowchart does not load, here is the quick rule of thumb:

1. Does the task involve explanation, brainstorming, or writing? Use browser chat.
2. Does the task require reading or editing files on your computer? Use a CLI tool.
3. Can’t install CLI tools, but need to build? Use a cloud sandbox (Claude Code web, Codespaces). See Lesson 4.
4. Does it need both planning and building? Start with browser chat to plan, then switch to a builder (CLI or web) to execute.

Real tasks are often a mix. For example, debugging might start with browser chat to reason about the error, then move to a CLI tool to test the fix in your codebase. Tool choice is not always black and white — use your judgment and experiment.

The framework: 10 real scenarios

Here is how the decision plays out in practice. Study this table — it covers the most common situations you will encounter:

Why CLI tools are better for building

When you paste code into a browser chat, there is a lot of friction:

1. You copy code from the chat
2. You paste it into a file
3. You realize you need to copy it into the right file
4. Something does not work
5. You copy the error message back into the chat
6. You get new code
7. You copy-paste again
8. Repeat 10-50 times

With a CLI tool:

1. You describe what you want
2. The tool reads your project, makes the changes, and runs the code
3. If something breaks, it sees the error and tries to fix it
4. You review the result and confirm — this often takes a few iterations

The CLI tool can access the project scope you grant it, which is usually far richer context than pasted snippets. It knows your file structure, your existing code, and your dependencies. This makes it dramatically more effective than copying code back and forth in a browser window.

Here is a concrete example. Instead of pasting code into browser chat and copying the result back, you would open your terminal, start the tool, and describe what you want:

claude
> Add a contact form to my website with name, email, and message fields

The tool reads your project, creates or edits the right files, and you see the result immediately. (You’ll learn the full workflow in Module 6.)

Common misconceptions

“I should use the CLI for everything now” No. Browser chat is still the best tool for conversations, brainstorming, and quick questions. Use the right tool for the job.

“Browser chat can do the same thing if I paste my code” Technically, yes. Practically, no. The copy-paste workflow is slow and error-prone. CLI tools see your whole project, run commands, and iterate automatically. It is a completely different experience.

“CLI tools are for developers only” CLI tools are becoming more beginner-friendly, though comfort with terminal basics still helps. That is exactly the skill you will practice throughout this course.

“I need to understand the code the CLI produces” Not line by line, no. You need to understand what it did (created a form, added a route, updated a style) and whether it works (does the page load? does the form submit?). That said, you should review changed files at a high level, run tests when available, and verify behavior before shipping anything. Trust the tool to write code, but trust yourself to check the result.

Practice: pick the right tool

For each scenario below, decide whether you would use browser chat, a CLI tool, or both.

Key takeaways

• Browser chat is for thinking; builders are for doing. Builders live in your terminal (CLI tools) or in your browser (Claude Code web, Codespaces).
• Use browser chat for questions, brainstorming, learning, and writing tasks.
• Use CLI tools for building, editing files, debugging, and multi-step project work.
• There is overlap. Many tasks can be done with either tool. The question is which is faster and more reliable for that specific job.
• Context is the CLI tool’s superpower. It reads your project, so it builds things that actually fit.
• When in doubt: start with browser chat to plan, then switch to the CLI tool to build.