I evaluated the leaked system prompts of the biggest AI coding tools. Here's what I found.

There's a GitHub repository with the full system prompts of Cursor, Windsurf, Lovable, Bolt, and v0 — all leaked or extracted from production. I ran every single one through PromptEval , a tool I built to evaluate prompt quality across 4 dimensions: clarity, specificity, structure, and robustness. Here's what the data says. The results Tool Score Clarity Specificity Structure Robustness Lovable 76.25 75 83.5 77.5 69 Bolt 73.38 75 76.5 83.5 58.5 Windsurf 72.63 75 71.5 79 65 Cursor 71.50 75 75 77.