aider - AI Pair Programming in Your Terminal

Aider is an open-source AI pair programming tool that operates directly in your terminal. It works best with Claude 3.7 Sonnet, DeepSeek R1 & Chat V3, OpenAI o1, o3-mini & GPT-4o, but can connect to almost any LLM, including local models. Aider makes a map of your entire codebase, which helps it work well in larger projects. Solo developers prefer it for its minimal overhead and precise surgical code changes without disrupting existing workflows.

Strengths

Terminal-native workflow eliminates context switching between IDE and AI assistant
Automatically lint and test your code every time aider makes changes
Makes a map of your entire codebase, which helps it work well in larger projects
Add images and web pages to the chat to provide visual context, screenshots, reference docs
Speak with aider about your code using voice commands
Completely free but requires your API keys

Weaknesses

Requires comfortable terminal usage and command-line proficiency
The pricing can get high when using API calls extensively
No built-in IDE features like syntax highlighting or debugging
You have to wait for AI responses during development flow

Best for

Command-line developers and terminal power users who want precise AI assistance without GUI overhead.

Pricing plans

Free — $0/cycle — Completely free but requires your API keys

Tech details

Type: Command-line AI coding assistant
IDEs: Aider can watch your files and respond to AI comments you add in your favorite IDE or text editor
Key features: Voice-to-code, automatic testing, linting, image/web page context, prompt caching
Privacy / hosting: Self-hosted, runs locally, connects to external LLM APIs
Models / context window: Claude 3.7 Sonnet, DeepSeek R1 & Chat V3, OpenAI o1, o3-mini & GPT-4o, plus local models

When to choose this over Windsurf

You prefer terminal-based development workflows over GUI applications
You want complete control over LLM provider and API costs
You need voice-controlled coding or advanced codebase mapping features

When Windsurf may be a better fit

You prefer integrated IDE experiences with visual interfaces
You want predictable subscription pricing instead of pay-per-use API costs
You need extensive built-in debugging and project management tools

Conclusion

Aider serves developers who want powerful AI assistance without leaving their terminal environment. Among Windsurf alternatives, it stands out for its surgical precision and voice integration capabilities. It processes files for just $0.007 each, making it cost-effective for focused development work.