kemiljk Vercel Doctor
Scans your Next.js codebase for patterns that drive up your Vercel bill, focusing on compute duration, function invocations, and bandwidth optimization.
Usage
```bash npx -y vercel-doctor@latest . --verbose --diff ```
Cost Optimization Scans
1. Function Duration
- Dead Code Detection — Removes unused files and exports to speed up cold starts.
- Parallel Execution — Identifies sequential await statements that can be run in parallel with Promise.all() to reduce function execution time.
- Server Post-Processing — Recommends using after() for non-blocking tasks to end the response earlier.
2. Caching & Invocations
- Client-Side Fetch Detection — Flags useEffect + fetch patterns in pages/layouts that should be server-side (eliminates API round-trips).
- Vercel Platform Checks — Scans for force-dynamic, missing cache policies, no-store fetches, and GET handlers with side effects that prevent ISR.
3. Bandwidth & Image Optimization
- Image Optimization — Detects global image optimization disabled, next/image with SVG without unoptimized, missing sizes, and overly broad remote patterns.
- Static Assets — Finds large static files that consume CDN bandwidth.
Workflow
Run after making changes to catch cost-heavy patterns early. Focus on fixing issues that reduce function execution time and invocations first.