7 Frequently Asked Questions About Aider | What Beginners Want to Know First

If you're just getting started with programming, you might feel anxious thinking "writing code seems really hard" or "I don't know how to fix errors when they come up." That's where Aider, an AI pair programmer that runs in your terminal, comes in. In this article, we'll gently answer the questions beginners most want to know about Aider.

What You'll Learn in This Article

• What kind of tool Aider is and what it can do
• Whether it's free and how much it costs
• Whether it can be used in Japanese and how accurate it is
• Whether commercial use and copyright are handled properly
• How to deal with problems when you get stuck, and what the future holds

So What Exactly Is Aider?

Aider is an open-source (free for anyone to use) AI pair programmer that runs in the terminal (the command-line screen with a black background). Just tell it in natural language — "create a login screen" or "add error handling to this function" — and the AI will actually write the code for you. On top of that, it automatically records the code it writes to Git (a version control tool), so you can rest easy if you ever want to undo a recent change. As of May 2026, it has been installed more than 4.1 million times worldwide and has over 39,000 stars on GitHub — a testament to its popularity. The greatest appeal is that even programming beginners can write code as if a seasoned engineer were sitting right next to them.

Q1: Is It Free? How Much Does It Cost?

Aider itself is completely free. It's open source, so anyone can download it and start using it right away. However, to run the AI, you need an API key (access credentials) for an LLM (an AI that can understand and write text like a human), and that's where costs come in. For example, if you use Claude Sonnet 4.6 and write code for about 50 hours a month, you can expect API costs of around $30–$80 (approximately ¥4,500–¥12,000). For casual daily use, it's said to run about $5–$20 per month (approximately ¥750–¥3,000). If you don't want to spend any money, you can use Ollama (a local AI that runs on your own computer) to bring API costs down to zero. For beginners, it's recommended to start by trying the free-tier options from the OpenAI API or Anthropic API.

Q2: Can It Be Used in Japanese? How Accurate Is It?

Yes, Aider can be used in Japanese. If you type instructions in Japanese in the terminal — such as "create a login screen" or "make the variable names easier to understand" — it will understand you and write the code accordingly. Accuracy varies depending on which LLM you choose, but using a recent model like Claude Sonnet 4 or GPT-4o will often produce code that is much more precise and clean than what a beginner might write. The May 2026 update added support for new models such as Gemini 2.5 and o3-pro. Japanese-language accuracy has also been improving year by year — sometimes just saying "there's an error" is enough for it to find the cause and fix it. That said, for complex requests or specialized business logic, providing instructions in English may yield better accuracy.

Q3: Is Commercial Use and Copyright Okay?

Aider itself is open source under the Apache 2.0 license (commercial use permitted), so using it for work is perfectly fine. However, the copyright of AI-generated code depends on the terms of the LLM you use. For example, OpenAI and Anthropic state that "content generated via the API belongs to the user," but there is a non-zero chance that generated code may resemble existing code included in training data. For commercial projects, it's a good idea to verify that the generated code does not violate the licenses of any existing libraries or frameworks. Also, if you're passing confidential company information to the AI, be sure to review the API provider's privacy policy. Using a local LLM (Ollama) means your code is never sent to an external server, which provides additional peace of mind.

Q4: How Is It Different from Competing Tools?

Tools similar to Aider include GitHub Copilot (a VSCode extension provided by Microsoft) and Cursor (an AI-powered editor). GitHub Copilot is known for providing in-editor completions and operates on a subscription of $10 per month. Cursor is also editor-integrated, at around $20 per month. Aider, on the other hand, runs in the terminal, is free at its core, and lets you freely switch between more than 30 LLMs — that's its biggest differentiator. For example, you can mix and match: "use a cheaper model for experimentation today, and switch to a high-accuracy model for important fixes." It also automatically commits edited code to Git, making version management easy. For beginners, Aider's appeal lies in being able to "try various AIs" and "get started for free."

Q5: Can It Be Used on a Smartphone?

Unfortunately, Aider cannot be used on a smartphone. Because Aider is a tool that runs in the terminal (command line), a computer is required. Specifically, it runs on Windows, Mac, or Linux with Python 3.9 or higher installed. If you want to program on a smartphone, consider alternatives such as the GitHub Copilot mobile app or browser-based tools like Replit. In theory, Aider could run on a tablet (such as an iPad) if you install a terminal app, but the small screen may make it difficult to use comfortably. If you want to use Aider seriously, a computer is definitely recommended.

Q6: What Should I Do When I Get Stuck?

Common sticking points for beginners are setting up the Python environment during installation and registering API keys. The official site (aider.chat) has documentation in English, but Japanese-language guides are also growing in number on Qiita and various blogs. Searching for "Aider インストール 日本語" (Aider installation Japanese) will turn up articles that walk through the steps with screenshots. You can also post questions on GitHub Issues (the bug/question reporting page), where developers and other users may respond. When an error message appears, searching for that exact message on Google will often lead you to a solution. If you're still stuck, try asking in a programming learning community (Discord or Slack groups).

Q7: What Does the Future Hold for Aider?

Aider is under active development — the latest stable version, v0.86.2, was released in February 2026. Going forward, further support for new LLMs and improvements for handling larger-scale projects are expected. As of May 2026, Aider quickly added support for the latest models such as Claude Sonnet 4 and Gemini 2.5, and it will continue to grow smarter in step with advances in AI. Being open source also means developers around the world are continuously contributing bug fixes and new features. In the future, there is potential for a more intuitive UI to be added, or for collaboration features in team development to be enhanced. For programming beginners, AI assistants are sure to become an increasingly familiar presence going forward.

In Closing: Taking Your First Step

Here's a summary of the key points beginners want to know about Aider:

• Aider itself is free; AI API costs run about $5–$80 per month (free if using a local AI)
• It works in Japanese, and accuracy is high with the latest models
• Commercial use is permitted, but you should verify the licenses of generated code
• Unlike GitHub Copilot or Cursor, you can freely choose from more than 30 LLMs
• A computer is required; it cannot be used on a smartphone
• When stuck, make use of Japanese-language guides and communities
• Continued support for new models and feature additions can be expected

Even programming beginners can get professional-quality code with Aider. Start by trying it with a free-tier API and see if it's right for you. Once you take that first step, writing code is sure to become a lot more enjoyable.

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This article is a cross-post from AI Friends.