Here’s which Google AI developer tool to use for each situation

Do you remember packing for an extended trip twenty years ago? We had to load up a camera, a day planner, a pile of books, a handheld gaming device, a map-stuffed tourist guide, a phone, a CD player, and maybe some cashier’s checks. Now? Just remember your smartphone! 

This is an example of consolidation, but sometimes diversification happens. For example, it wasn’t long ago that your “computer” was simply a desktop PC that was your one device for everything. Now, we have laptops for portable work, tablets for casual digital consumption, smartphones for on-the-go internet, smart TVs for watching every type of content, and a myriad of gaming consoles. 

This dynamic reminds me of the current state of developer tooling. Until recently, it was fairly static — UX design tools for mock-ups, IDEs to write code, build systems to assemble artifacts, systems and shell scripting to get infrastructure and apps deployed. It’s become wildly more diverse and dynamic thanks to generative AI. What we do, and what we use, will never be the same.

So when do I use what? Google alone offers LLM interfaces like the Gemini app and Google AI Studio, IDE extensions like Gemini Code Assist, browser-based dev environments like Firebase Studio, along with agentic services like Jules and the Gemini CLI. It’s easy to feel overwhelmed. Let’s break it down.

This diversification of tools is due, in part, to the new ways AI can assist us in software engineering. 

• We now have delegated, agentic options. Think of outsourcing the work to a third party where you provide detailed instructions, and only have limited interactions until the work is complete. The goal here is to get the work done quickly, and you aren’t focused on growing your own knowledge.

• The next category is supervised, where you have AI acting more like someone who works for you. It’s more interactive, but you’re scaling by providing experience-based intent to an AI agent.

• The final category is collaborative. Here, we’re in a conversational interaction with an AI assistant, going back and forth as we “learn” together.

Key takeaways for each AI developer tool

Jules is best for explicit instructions that can drive unattended batch work—add documentation, improve test coverage, perform surgical code modernizations—against source code in GitHub.com

• No infrastructure or machinery to manage and update

• Iterate with Jules on a plan before sending it off to do work

• Get back a set of changes and a pull request to accept them

• No cost tier along with paid Pro and Ultra tiers

The Gemini CLI offers an open, fast, and flexible interface for working with code and content interactively or through delegation

• Lightweight CLI tool that only requires a local install of Node

• Many extensibility points including built-in tools along with support for MCP

• Built into other tools like Gemini Code Assist and Firebase Studio

• The open source Gemini CLI GitHub Actions are ideal for delegating background work to code repos—issue triage, pull request review—through async or user-initiated triggers

• Comes with generous free usage limits for premier Gemini models. It supports enterprise access through Vertex AI models and also works with your Gemini Code Assist license.

Gemini Code Assist provides a rich IDE extension for conversational or agentic interactions with a codebase

• Plug-in for Visual Studio Code and Jetbrains IDEs

• Offers code completion, test generation, code explanation, and code generation

• Extensibility through custom commands, tools support, and code customization on private codebases. Agent mode is powered by the Gemini CLI and enables more complex interactions

• Free tier along with per-user-per-month pricing for teams

Firebase Studio is the right choice when you want to build professional-grade software without the need to be a professional developer, while working in a Google-managed and browser-based dev environment

• Built-in templates for popular frameworks and languages to start your project

• Let Gemini vibe code your app or dive into the code thanks to the full power of an underlying customizable VM

• Configure the workspace environment using nix 

• No cost during preview, and more environments available for those who sign up for the Google Developer Program

Google AI Studio delivers the best way to interact with Google’s latest models, experiment with prompts, and vibe code lightweight web apps

• Generate media, use the Live API for interactive sessions, and write prompts against Gemini and Gemma models

• Write prompts, use tools, ground with Google Search, and run comparisons

• Get API keys to call Gemini models programmatically

• Generous free tier along with a paid tier offering higher rate limits, more features, and different data handling

Cheatsheet:

• Choose the Gemini app for quick app prototyping

• Choose Google AI Studio for prompt experimentation with specific models and capabilities.

• Choose Gemini Code Assist for AI-assisted software development in your environment, with your preferred toolchain.

• Choose Firebase Studio when you want to come to a fully Google-managed environment to prototype or vibe code beautiful software without needing to be a full-time software developer.

• Choose the Gemini CLI when you’re working with a wide array of generative AI projects and want the speed and portability of an agentic CLI.  And choose the Gemini CLI GitHub Actions when you want to use Google Cloud security and models while triggering interactive or background tasks for GitHub-based projects.

• Choose Jules when you’ve got GitHub-based projects that need changes that can be clearly articulated in a set of instructions.

I haven’t seen software development tools change this much—or such an eager willingness to try anything new—at any time in my career. It’s exciting and confusing. It’s important to see these tools as complementary, and you’ll likely use a mix to accomplish your tasks. At Google, we’re going to continue to focus on giving you the best AI tools to build the best AI apps. Let us know how to make both experiences better!