Best Open-Source AI Code Assistants 2026: 6 Options Compared
Best open-source AI Code Assistants compared: aider, Cline, Continue, goose and 2 more, with licenses, platforms and prices from official pages checked October 22, 2026.
•4 min read•AI Coding & Local LLMs
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| aider | Free (free tool; you pay your LLM provider or run local models) | Terminal (Python) | Terminal users who want clean git history | Docs only |
| Cline | Free (free open-source agent; you use your own AI provider) | VS Code, JetBrains, macOS, Windows, CLI | VS Code users wanting an autonomous agent | Docs only |
| Continue | Free (free open-source extension and CLI; you bring your own model or API key) | VS Code, JetBrains | Mixing autocomplete and chat in one tool | Docs only |
| goose | Free (Free open-source agent; you pay any LLM provider you connect) | macOS, Windows, Linux | Running an agent with a local model | Docs only |
| OpenCode | Free (Free to use, includes a set of free models; other providers may cost extra) | macOS, Windows, Linux | Switching between many model providers | Docs only |
| Codex CLI | Free (The CLI is free open-source software; usage is covered by a ChatGPT plan or paid at API rates); paid from $20 per month (ChatGPT Plus; Codex in the CLI listed as included) | macOS, Windows, Linux | Teams already paying for ChatGPT | Docs only |
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Good fit if
- You live in the terminal and care about git history (aider is the pick)
- You use VS Code and want an agent (Cline is the pick)
- You want autocomplete plus chat (Continue is the pick)
- You want to run everything on local models (goose is the pick)
- You want maximum provider choice (OpenCode is the pick)
Not ideal if
- You cannot host, patch and back up a server yourself and want a vendor to run it
Most open-source AI code assistants are free shells around a model you pay for or run yourself, and that is the main thing to understand before choosing. The tools here are Apache-2.0 or MIT licensed, so you can read what they send and change how they work, but the quality of the code they write depends almost entirely on the model behind them. Plug in a top hosted model and you will pay API rates, which can be a surprise on long agent sessions. Plug in a local model through Ollama and you pay nothing per token, but you will notice slower and less reliable results on complex edits. The tools differ in shape. Aider works in the terminal and commits its changes to git, which makes mistakes easy to undo. Cline and Continue live inside your editor. Goose and OpenCode offer agents with a desktop or terminal interface. The Codex CLI is open source too, though it is tied closely to OpenAI plans. If you are new to this, start with the editor extension you already know, use a small budget cap on your API key, and review every diff. Choose by where you work, not by feature lists, since the habits you build around a tool matter more.
aider
Apache-2.0 terminal assistant that maps your codebase and commits each change to git automatically, so every edit is easy to review or revert. You supply the model, hosted or local.
Price: Free (free tool; you pay your LLM provider or run local models) (aider pricing, checked 2026-10-22).
Platforms and license: Terminal (Python). Apache-2.0 (open source) (license source).
Project activity: 49.8k GitHub stars · latest release v0.86.0 (Aug 9, 2025) · last commit May 22, 2026
Best for: Terminal users who want clean git history.
Worth knowing: Maps your codebase and commits changes to git automatically.
Cline
Apache-2.0 agent inside your editor with support for Anthropic, OpenAI, Google and Ollama models. It is free; you use your own provider, so costs track your usage.
Price: Free (free open-source agent; you use your own AI provider) (Cline pricing, checked 2026-10-22).
Platforms and license: VS Code, JetBrains, macOS, Windows, CLI. Apache-2.0 (open source) (license source).
Project activity: 70.9k GitHub stars · latest release v4.1.26 (Oct 26, 2026) · last commit Oct 27, 2026
Best for: VS Code users wanting an autonomous agent.
Continue
Apache-2.0 extension and CLI covering chat, edit, agent and autocomplete modes. It is free and takes your own model or API key, including local ones.
Price: Free (free open-source extension and CLI; you bring your own model or API key) (Continue pricing, checked 2026-10-22).
Platforms and license: VS Code, JetBrains. Apache-2.0 (open source) (license source).
Project activity: 36.3k GitHub stars · latest release v2.0.0-vscode (Jun 19, 2026) · last commit Oct 27, 2026
Best for: Mixing autocomplete and chat in one tool.
goose
Apache-2.0 desktop app and CLI agent that works with 15 or more providers including Ollama. Free, with provider costs only.
Price: Free (Free open-source agent; you pay any LLM provider you connect) (goose pricing, checked 2026-10-22).
Platforms and license: macOS, Windows, Linux. Apache-2.0 (open source) (license source).
Project activity: 55.8k GitHub stars · latest release v1.56.0 (Oct 23, 2026) · last commit Oct 27, 2026
Best for: Running an agent with a local model.
Worth knowing: Desktop app and CLI; works with 15+ providers including Ollama.
OpenCode
MIT terminal, desktop and IDE agent supporting 75 or more providers. It includes a set of free models; other providers may cost extra.
Price: Free (Free to use, includes a set of free models; other providers may cost extra) (OpenCode pricing, checked 2026-10-22).
Platforms and license: macOS, Windows, Linux. MIT (open source) (license source).
Project activity: 222.4k GitHub stars · latest release v1.19.4 (Oct 22, 2026) · last commit Oct 28, 2026
Best for: Switching between many model providers.
Worth knowing: Terminal UI, desktop app and IDE extension; works with 75+ providers or Claude Pro/Max, ChatGPT or Copilot subscriptions.
Codex CLI
Apache-2.0 command-line agent from OpenAI. The CLI is free, but usage runs through a ChatGPT plan or API rates, so it is open source in code rather than free to use.
Price: Free (The CLI is free open-source software; usage is covered by a ChatGPT plan or paid at API rates); paid from $20 per month (ChatGPT Plus; Codex in the CLI listed as included) (Codex CLI pricing, checked 2026-10-22).
Platforms and license: macOS, Windows, Linux. Apache-2.0 (open source) (license source).
Project activity: 131.3k GitHub stars · latest release rust-v0.165.0 (Oct 27, 2026) · last commit Oct 27, 2026
Best for: Teams already paying for ChatGPT.
Which one to pick
- You live in the terminal and care about git history: aider
- You use VS Code and want an agent: Cline
- You want autocomplete plus chat: Continue
- You want to run everything on local models: goose
- You want maximum provider choice: OpenCode
Limits of this review
Docs-only for aider, Cline, Continue, goose, OpenCode, Codex CLI: we did not install or run them, so feature claims come from vendor pages. Vendor prices and free limits change; confirm on the linked pricing page before you commit.
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Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing, license and product pages checked 2026-10-22: aider, Cline, Continue, goose, OpenCode, Codex CLI. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.