Harness Comparison: Copilot vs Pi vs Claude Code vs OpenCode
Choose harnesses with fewer LLM requests for faster performance.
Select a harness that minimizes LLM requests to improve speed.
Summary
The author benchmarks the same Qwen3.6 27B model across four harnesses, measuring LLM requests, output tokens, and duration. Copilot requires 13 requests, 21,184 tokens, and 14 min 26 s, while Pi, Claude Code, and OpenCode each need only 4 requests, around 5,000–7,000 tokens, and roughly 3 min. OpenCode can search the internet by default, improving web‑dev results, and delivers interactive widgets. Copilot struggles with file‑editing tools, leading to many retries.
Qwen3‑vl‑4 loops endlessly in OpenCode, preventing file creation. The benchmark demonstrates that harness choice dramatically affects performance and cost. The detailed table shows the trade‑offs for each harness, guiding developers to select the most efficient option.
Key changes
- Copilot requires 13 LLM requests, 21,184 tokens, 14 min 26 s.
- Pi needs 4 requests, 4,853 tokens, 3 min 3 s.
- Claude Code needs 4 requests, 5,156 tokens, 3 min 38 s.
- OpenCode needs 4 requests, 6,974 tokens, 3 min 37 s.
- OpenCode can search internet by default, improving web‑dev results.
- Copilot struggles with file‑editing tools, causing many retries.
- Qwen3‑vl‑4 loops endlessly in OpenCode.
- Harness choice dramatically affects performance.