# free-pi vs Aider

Canonical: https://freepi.ai/vs/aider

Facts checked on 2026-10-28 from official sources.

Aider is a well-known open-source coding assistant for your terminal, and it connects to almost any model. The catch is that you bring the model: its docs show setup with a provider API key. free-pi skips that step. Run `npx free-pi-cli`, sign in with GitHub, and start.

Try it: `npx free-pi-cli@latest`

## Why developers pick free-pi
- **Free, no card, no API key** — Sign in with GitHub and start.
- **Web search and live library docs, built in** — free-pi can search the web and pull current docs for the library you are using, with no API keys to set up.
- **Seconds to first prompt** — `npx free-pi-cli`, click through GitHub, and start coding.
- **A fresh allowance every day** — Your free daily allowance refills every day.
- **Pick your model** — Choose from a catalog with DeepSeek V4 Flash as the default.
- **Lean, extensible, open** — Built on Mario Zechner's pi agent harness, with an MIT-licensed CLI you can read on GitHub.

## At a glance
| | free-pi | Aider |
|---|---|---|
| Open-source CLI | ✓ MIT | ✓ Apache-2.0 |
| API key needed | ✓ None | Its docs show hosted models set up with a provider API key |
| Card needed | ✓ No | Depends on the model provider you choose |
| Install | `npx free-pi-cli`, no install step | `aider-install` (via pip), a script, uv, or pipx; Python 3.8-3.13 for the quick start |
| Models | Catalog in `/model`, DeepSeek V4 Flash by default | "Almost any LLM, including local models" |
| Git | Works in your repo | Automatically commits changes with sensible commit messages |
| Codebase overview | Reads and searches your project with built-in tools | Builds a map of your entire codebase |
| Voice input | Not documented | ✓ Documented |
| MCP servers | ✓ `free-pi-cli mcp add` | Not mentioned in the pages we checked |
| Web search and docs lookup | ✓ Built in | `/web <url>` scrapes a page you name; web search not mentioned in the pages we checked |
| Security work on systems you own | ✓ Opt-in Defense models (abliterated) in `/model`, plus a bundled security-audit skill | Not documented in the pages we checked |

## Where Aider is strong
Aider has real strengths. It commits each change to git for you, so undoing an edit is a normal git operation. It builds a map of your whole codebase to help on larger projects. It can lint and test after each change, and it takes voice input. If you want to choose any model yourself, including one running on your own machine, Aider is built for that.

## Where free-pi is easier
You do not pick a provider, create an account with it, or paste a key. You also do not manage a Python install. The cost is less choice: free-pi's model list comes from free-pi, and your provider keys are hidden from the picker by default.

## Cybersecurity work
free-pi has an opt-in Defense section in `/model`. Its models are abliterated, which means open-weight models with their refusal behavior removed, and free-pi also bundles a security-audit skill. Use them for lawful security work: systems you own, employer systems you have permission to test, and in-scope bug bounty targets.

We built it because defenders need to find and fix vulnerabilities, and a refusal on lawful work on your own systems slows them down. Defense is for signed-in users and authorized use only. See [free-pi Defense](https://freepi.ai/cybersecurity).

## Which one should you use?
### Pick free-pi if…
- You want to start in under a minute with no key and no card.
- You want web search, live library docs and MCP servers built in.
- You like a free daily allowance that refills on its own.

### Pick Aider if…
- You want to use any model you choose, including local ones.
- You want every change committed to git automatically.
- You like repo maps, voice input, and lint-and-test after each change.
- You already have a provider key and are happy to pay that provider directly.

## FAQ

### Is Aider free?

The tool is open source under Apache-2.0. Its docs show it connecting to model providers with your API key, so model usage is billed by whichever provider you choose. We did not find pricing for Aider itself on its pages.

### Does Aider need an API key?

Its docs show hosted models set up with a provider API key. They also say it can connect to local models.

### How does free-pi stay free?

Ads in your terminal and session data that helps train better models. That's the deal that keeps it free.

## Sources

- [Aider documentation](https://aider.chat/docs/)
- [Aider on GitHub](https://github.com/Aider-AI/aider)
- [Aider install docs](https://aider.chat/docs/install.html)
- [Aider home page](https://aider.chat/)
- [Aider in-chat commands](https://aider.chat/docs/usage/commands.html)
- [Security-audit skill and Defense](https://freepi.ai/cybersecurity)
- [free-pi CLI on GitHub](https://github.com/dennisonbertram/free-pi-cli)
- [freepi.ai](https://freepi.ai)

Aider is a trademark of its owner. free-pi is not affiliated with or endorsed by Aider.