Free · Coding · 16 of 19 tools · updated Oct 17, 2026
Free AI tools for autonomous coding agent
OpenAI Codex is the strongest tool for autonomous coding agent you can use without paying, at 97/100. What you get for nothing: Included with ChatGPT Plus $20/mo and Pro; CLI free with API key. 16 of the 19 tools tracked for this job have a free tier, an open-source licence, or are free outright. It is also the top-ranked tool for this job overall, free or not.
Same evidence score as the ranking — GitHub stars, Hacker News mentions, release activity, free access — recomputed nightly, never sold. See all 19 tools for autonomous coding agent.
Top 3
evidence / 100
+ Cloud mode runs many tasks in parallel sandboxes and opens PRs for each.
− Native Windows support in the CLI arrived late and sandboxing can block legitimate commands.
+ Free tier gives a 1M-token context window and around 1,000 requests per day.
− Less reliable at multi-step edits than Claude Code and quietly falls back to Flash under load.
+ Top-ranked open agent on SWE-bench that you can run on your own infrastructure.
− Docker-based local setup is heavy and the UI is rougher than commercial agents.
All 16, side by side
| Tool | Score | Pricing | What you get free | Platforms |
|---|---|---|---|---|
| OpenAI Codex | 97 | Free tier | Included with ChatGPT Plus $20/mo and Pro; CLI free with API key | cli, web, vscode-extension, mac, linux |
| Gemini CLI | 96 | Open source | Free tier with generous daily limits; API billing beyond | cli, mac, windows, linux |
| OpenHands | 95 | Open source | Self-host free; cloud credits | web, cli, linux, mac |
| GGoose | 92 | Open source | Free; bring your own model | cli, mac, linux, windows |
 Cline | 92 | Open source | Free; bring your own API key | vscode-extension, cli |
 Kilo Code | 88 | Open source | Free; models billed at provider cost | vscode-extension, jetbrains-plugin, cli |
 Claude Agent SDK | 80 | Open source | Free; pay Claude API usage | cli, api |
 Aider | 77 | Open source | Free; pay your own model API costs | cli, mac, windows, linux |
 Cursor | 62 | Free tier | Pro $20/mo | mac, windows, linux |
 GitHub Copilot | 53 | Free tier | Free tier; Pro $10/mo; Pro+ $39/mo | vscode-extension, jetbrains-plugin, cli, web |
 Roo Code | 35 | Open source | Free; bring your own API key | vscode-extension |
 Kiro | 26 | Free tier | Free tier; Pro $20/mo | mac, windows, linux |
 Amp | 11 | Free tier | Pay-as-you-go credits; ad-supported free mode | vscode-extension, cli, mac, windows, linux |
 JetBrains AI Assistant & Junie | 11 | Free tier | AI Pro $10/mo; included in All Products Pack | jetbrains-plugin, mac, windows, linux |
 Windsurf | 11 | Free tier | Pro $15/mo | mac, windows, linux, vscode-extension, jetbrains-plugin |
 Jules | 9 | Free tier | Free tier; higher limits with Google AI Pro/Ultra | web, cli |
A free tier counts, and so does an open-source licence you can self-host — both are in the table, so a tool that is only free for a trial is not here.
Head to head: OpenAI Codex vs Gemini CLI OpenAI Codex vs OpenHands Gemini CLI vs OpenHands