Aider vs Claude Code
Aider is free and open source (Apache-2.0) and works with models from many providers; you pay the model provider per token. Claude Code is a paid product at $20 to $200 a month. Running Aider for regular daily work costs roughly $74 a month in API fees on Claude Sonnet 5.5, or $9.25 on DeepSeek V4.1 Flash.
GitHub data updated October 18, 2026; Claude Code prices verified October 18, 2026.
Side by side
| Aider | Claude Code | |
|---|---|---|
| Price | Free; you pay for model usage | $20 to $200 a month |
| Source code | Open source (Apache-2.0) | Proprietary (Anthropic) |
| Made by | Aider AI | Anthropic |
| Runs in | Terminal | Terminal, IDE extensions, desktop and web |
| Models | Almost any LLM, including local models | Anthropic’s Claude models only |
| Local models | Yes | Not officially supported |
| GitHub stars | 49,618 | — |
| Last commit | May 22, 2026 | — |
What is Aider?
AI pair programming in the terminal. Aider edits files in your git repository and commits each change with a descriptive message, so you can diff or undo it with normal git tools.
No release since v0.86.0 in August 2025, so newer models and features may lag.
Aider on GitHub ↗Docs ↗49.6k stars
Aider on your own API key vs Claude Code plans
Estimated monthly API fees for Aider, by model and usage:
| Model on your API key | Light 300 steps/mo | Regular 1,500 steps/mo | Heavy 6,000 steps/mo |
|---|---|---|---|
| Claude Opus 5.5 | $28 | $140 | $562 |
| Claude Sonnet 5.5 | $15 | $74 | $298 |
| GPT-6.1 Sol | $14 | $70 | $281 |
| Gemini 3.8 Flash | $5.58 | $28 | $112 |
| DeepSeek V4.1 Flash | $1.85 | $9.25 | $37 |
| Claude Haiku 5.5 | $0.74 | $3.72 | $15 |
For comparison, Claude Code: Claude Pro $20/mo ($17/mo billed yearly); Claude Max 5x $100/mo; Claude Max 20x $200/mo.
Each agent step is assumed to send about 40,000 input tokens (70% read from the prompt cache) and return about 2,000 output tokens, as in our cost calculator’s coding-agent scenario. Light is about one short task a day, regular is several tasks every working day, heavy is agents running most of the day. Real usage varies with the size of your codebase and how each tool manages context, so treat these as orders of magnitude. A local model costs nothing per token but needs hardware that can run it.
Which should you pick?
- Choose Claude Code if you want a flat monthly price with usage included; it runs Anthropic’s Claude models only.
- Choose Aider if you want to choose your own models or run local ones, pay only for the tokens you use, or read and change the source code.
- Light or occasional use? Paying per token often costs less than any plan; check your numbers in the subscription vs API calculator.
Frequently asked questions
- Is Aider free?
- Yes, Aider is free and open source under Apache-2.0. The models it calls are not: you pay your provider per token, unless you run a local model. Regular use costs roughly $74 a month on Claude Sonnet 5.5.
- Is Aider better than Claude Code?
- Neither wins outright. Claude Code gives you a flat monthly price ($20 to $200 a month) with usage included. Aider is better if you want to choose your own models or run local ones, pay only for the tokens you use, or read and change the source code.
- Can Aider use Claude models?
- Yes. Aider works with almost any LLM, including local models. With an Anthropic API key you can run Claude Sonnet 5.5 or Claude Opus 5.5 and pay Anthropic’s per-token prices.
- How much does Aider cost per month?
- Aider itself costs nothing. API fees at about 1,500 agent steps a month come to roughly $140 on Claude Opus 5.5, $74 on Claude Sonnet 5.5 and $70 on GPT-6.1 Sol.
All open-source Claude Code alternatives · Also compared: OpenCode vs Claude Code, Cline vs Claude Code, Gemini CLI vs Claude Code.