Best Free AI Coding Agent 2026

Three include free model access: OpenCode (free models on its Zen gateway, line-up rotates), Kilo Code (free models, no card) and Google Antigravity (a free Individual plan with weekly limits). Cline, Pi and Aider are free open-source tools where you supply the model: an API key, a local model (genuinely $0), or a flat-price plan such as Standard Compute. Gemini CLI is no longer free: Google switched free accounts to Antigravity CLI on June 18, 2026.

On code quality it can be, because quality comes mostly from the model: a free open-source agent like OpenCode or Cline running a frontier model holds its own against paid editors. The free models themselves are a step down from frontier models. What you also give up is polish: paid editors integrate completions, chat, and agents into one smooth experience, while free tools ask for more setup in exchange for zero lock-in.

Both ended in 2026. Google announced on May 19 that Gemini CLI would stop serving free accounts and Google AI Pro/Ultra subscribers on June 18, 2026, and moved them to Antigravity CLI. Qwen Code's free Qwen OAuth tier was cut from 2,000 to 1,000 requests a day in February and discontinued on April 15, 2026. Both tools are still open source and work with paid model access.

Pay-per-token APIs typically run anywhere from a few dollars to hundreds per month depending on usage, and heavy agent use burns tokens fast. The two ways to make costs predictable: run a local model (free, lower quality) or use a flat-price plan like Standard Compute.

Yes. Besides OpenCode's and Kilo Code's free models, Antigravity's free plan and local models, Standard Compute gives new accounts a small free starter credit: sign up (no card required), activate your account from the dashboard, and the credit unlocks. Then point any of these agents at the api.stdcmpt.com/v1 base URL and run real requests on real models before deciding whether a paid plan is worth it.