First-party only — a session id and where you arrived from, so we can tell which pages are worth writing more of. No advertising, no third-party trackers, nothing that follows you off this site.
Both are on this list because they are genuinely good at something. The question is which something you need. Below is the factual comparison, then the honest answer about who each one is for.
Reviewed July 25, 2026 · pricing changes often, check the vendor
| Claude Code | Aider | |
|---|---|---|
| Made by | Anthropic | Paul Gauthier / community |
| Where it runs | Terminal | Terminal |
| Models | Claude models only (Opus / Sonnet / Haiku tiers) | Provider-agnostic — Anthropic, OpenAI, Google, local models |
| Pricing | From $20/mo (Pro) · usage-based API also available | Free and open source · you pay your own model costs |
| Open source | No | Yes |
| Best for | Multi-file work in a repo you can describe well — the more context you put in CLAUDE.md, the further ahead it gets. | People who want the agent's output to arrive as reviewable commits and want control over which model runs. |
Configuration is a first-class feature — memory files, skills, hooks and permissions are documented and versionable in the repo
Works on the real filesystem and the real shell, so it can run your tests instead of guessing whether they pass
Subagents let you fan work out without polluting the main context window
Anthropic models only — you cannot point it at a different provider
Terminal-first, which is a poor fit if you want inline autocomplete while you type
Heavy usage on the $20 plan runs into limits fast; the useful tiers cost more
Commit-per-change makes review and rollback the normal git workflow instead of a special case
Genuinely model-agnostic, including local models
The repo map keeps token spend sane on large codebases
No inline completion — it is a conversation, not an editing assistant
You manage your own keys, costs and model selection
Less polished than the commercial options, by design
Pick Claude Code if multi-file work in a repo you can describe well — the more context you put in CLAUDE.md, the further ahead it gets.
Pick Aider if people who want the agent's output to arrive as reviewable commits and want control over which model runs.
And a thing worth saying plainly: the gap between these two is smaller than the gap between a repo that tells an agent what it is and one that does not. If you are choosing between them to fix inconsistent output, the tool is probably not the variable. The free Foundations track covers the part that is.