Aider vs Cline

Last reviewed Aug 26, 2026 · 754 words

Point both at the same model and the code is roughly the same; what differs is where you sit and what stops the agent. Aider is a Python CLI that edits files in a git repository and commits each change automatically. Cline is a VS Code extension that plans, edits, and executes with a confirmation prompt before anything lands. Both are Apache-2.0, both list 512 MB minimum RAM for the tool itself, and both carry the same catalogue con: "API costs add up". The real question is whether your workflow is a terminal and a git log, or an editor and a diff view.

Aider: the terminal, and git as the interface

You run aider in a repo, /add the files that matter, and type what you want. Aider builds a tree-sitter repository map so the model sees the codebase's shape without you pasting it in, then applies edits and commits them with a generated message. /undo reverts the last commit; git log shows you the whole session. That is the entire safety model. The --watch-files mode lets you leave an instruction as a code comment in any editor, marked with the letters AI and a bang, and Aider picks it up from the terminal. It supports OpenAI, Anthropic, Gemini, OpenRouter, and local models through ollama/ prefixes, and the architect mode lets a strong model plan while a cheaper one edits, which is the single best cost lever either tool offers. What it does not have is a place to click. The product is the shell, which is why it works the same from a laptop or over SSH to a box in a rack.

Cline: the editor, and approval as the interface

Cline sits in the VS Code sidebar with two modes: Plan, where it reads the codebase and proposes an approach, and Act, where it edits files, runs terminal commands, and can drive a browser to check the result. Each edit shows as a diff you accept or reject; each command asks first unless auto-approved. Checkpoints let you roll the workspace back to any point in a task without touching git. Model Context Protocol support means it uses the same MCP servers as other agents. The VS Code dependency is the cost. The catalogue lists it as VS Code only, and a terminal-first workflow on a headless server is still Aider's territory.

Local models: both work, neither is cheap in hardware

Both can be pointed at Ollama, LM Studio, or any OpenAI-compatible endpoint, so no code has to leave your network. The catch is that models that handle multi-file edits well are 30 B parameters and up; the VRAM math post has the arithmetic, but a 24 GB GPU is the realistic floor for a pleasant experience with either tool. Below that, Aider degrades more gracefully because its edit format is simpler; Cline's tool-calling loop needs a model that follows structured instructions reliably, and small local models often stall mid-task. On hosted APIs both display running token cost per session, and both will spend 5 dollars on a bad afternoon.

Where each one breaks

Aider's failure mode is context. Add too many files and the model gets worse; add too few and it edits blind. Knowing when to /drop is the skill. Cline's failure mode is autonomy: with auto-approve on it can re-run a failing test 10 times, and the diff-by-diff approval that makes it safe makes a 40-file refactor tedious. The AI pair programming workflow post covers habits that tame both, and Continue is the third option if you want editor integration without the agent loop.

Decision table

What I'd do

Install both; they coexist in the same repo. Use Cline for interactive work inside VS Code where you want to watch the agent think. Use Aider from the terminal on servers, in CI experiments, and for anything where a clean commit history is the deliverable. If forced to pick one for a solo developer on a laptop, Cline, because the approval loop catches more mistakes before they are committed.