The best AI coding agent in 2026 comes down to two numbers most reviews skip. The first is real cost per completed task. The second is how locked in you are to one vendor’s models. Across five named agents, only Aider runs any LLM, so you keep both price control and portability.
Key Takeaways
- Judge agents by cost per finished task, not the monthly sticker price.
- Aider is the only one that runs any model, so you keep price control.
- Claude Code, Codex CLI, and Gemini CLI each tie you to one vendor.
- Cursor routes everything through its own pricing, which is its own lock-in.
- Gemini CLI’s free individual tier stops on June 18, 2026.
How I Judge an AI Coding Agent: Cost Per Completed Task, Not Per Month
Most roundups rank agents on monthly subscription price. That is the wrong unit. What you actually care about is whether the agent finishes a real multi-file change and what that costs you end to end. So this whole comparison turns on two axes, and every section below answers one of them.






