Reduce your Vercel bill with one command.

Scans your Next.js codebase for patterns that increase your Vercel bill — long function durations, uncached routes, unoptimized images, expensive cron jobs, and more — then outputs actionable diagnostics.

See it in action →

Main.mp4

How it works

Vercel Doctor detects your framework and project setup, then runs two analysis passes in parallel:

1. Billing lint — detects patterns that inflate your Vercel invoice:
   • Function duration: sequential awaits, blocking after() calls, side effects in GET handlers
   • Caching: missing cache policies, force-dynamic / no-store overrides, SSR where SSG would work
   • Image optimization: global image optimization disabled, next/image with SVG without unoptimized, overly broad remote patterns, missing sizes prop
   • Invocations: Link prefetch default (use prefetch={false} or disable globally, then add prefetch={true} only to critical links)
   • Edge functions: heavy imports, sequential awaits that burn CPU time
   • Version-aware handling: Next.js 15/16+ caching guidance tailored to your detected Next.js major version
   • Static assets: large files that should be served from an external CDN
   • Build optimization: Turbopack build cache (Next.js 16+), getStaticProps without revalidate (consider ISR), large projects → vercel deploy --archive=tgz
   • Platform usage: Vercel Cron vs. GitHub Actions / Cloudflare Workers, Fluid Compute, Bun runtime
2. Dead code — detects unused files, exports, types, and duplicates that slow cold starts.

Diagnostics are filtered through your config to produce actionable results.

Install

Run this at your project root:

npx -y vercel-doctor@latest .

Use --verbose to see affected files and line numbers:

npx -y vercel-doctor@latest . --verbose

Install for your coding agent

Teach your coding agent Vercel cost optimization rules:

curl -fsSL https://vercel-doctor.com/install-skill.sh | bash

Supports Cursor, Claude Code, Amp Code, Codex, Gemini CLI, OpenCode, Windsurf, and Antigravity.

Options

Usage: vercel-doctor [directory] [options]

Options:
  -v, --version         display the version number
  --no-lint             skip linting
  --no-dead-code        skip dead code detection
  --verbose             show file details per rule
  --score               output only the score
  -y, --yes             skip prompts, scan all workspace projects
  --project <name>      select workspace project (comma-separated for multiple)
  --diff [base]         scan only files changed vs base branch
  --offline             skip telemetry (anonymous, not stored, only used to calculate score)
  --output <format>     output format: "human" (default), "json", or "markdown"
  --report <file>       write human-readable report to file
  --ai-prompts <file>   write AI fix prompts to JSON file for use with Cursor/Claude/Windsurf
  -h, --help            display help for command

Configuration

Create a vercel-doctor.config.json in your project root to customize behavior:

{
  "ignore": {
    "rules": ["vercel-doctor/nextjs-image-missing-sizes", "knip/exports"],
    "files": ["src/generated/**"]
  }
}

You can also use the "vercelDoctor" key in your package.json instead:

{
  "vercelDoctor": {
    "ignore": {
      "rules": ["vercel-doctor/nextjs-image-missing-sizes"]
    }
  }
}

If both exist, vercel-doctor.config.json takes precedence.

Config options

Key	Type	Default	Description
ignore.rules	string[]	[]	Rules to suppress, using the plugin/rule format shown in diagnostic output (e.g. vercel-doctor/async-parallel, knip/exports)
ignore.files	string[]	[]	File paths to exclude, supports glob patterns (src/generated/**, **/*.test.tsx)
lint	boolean	true	Enable/disable lint checks (same as --no-lint)
deadCode	boolean	true	Enable/disable dead code detection (same as --no-dead-code)
verbose	boolean	false	Show file details per rule (same as --verbose)
diff	boolean | string	—	Force diff mode (true) or pin a base branch ("main"). Set to false to disable auto-detection.

CLI flags always override config values.

Report Generation & AI Prompts

Generate detailed reports and AI-compatible fix prompts:

# Generate a markdown report
npx vercel-doctor . --output markdown --report report.md

# Export AI prompts for fixing issues (use with Cursor, Claude, Windsurf)
npx vercel-doctor . --ai-prompts fixes.json

The --ai-prompts flag generates ready-to-use prompts for AI coding tools. It only exports issues that have a known fix strategy. The format is auto-detected from the file extension:

• .json - Structured format for programmatic use and automation
• .md or .markdown - Human-readable format, easy to copy-paste into AI chats

# Export as JSON (for scripts, automation)
npx vercel-doctor . --ai-prompts fixes.json

# Export as Markdown (for manual copy-paste into Cursor/Claude/Windsurf)
npx vercel-doctor . --ai-prompts fixes.md

Each prompt includes:

• The specific rule violation
• File location, line, and column number
• Before/after code examples
• Step-by-step fix instructions

Example AI prompt output:

{
  "vercel-doctor/vercel-no-force-dynamic::src/app/page.tsx:15:1": "Fix this Vercel optimization issue..."
}

Node.js API

You can also use Vercel Doctor programmatically:

import { diagnose } from "vercel-doctor/api";

const result = await diagnose("./path/to/your/nextjs-project");

console.log(result.score); // { score: 82, label: "Good" } or null
console.log(result.diagnostics); // Array of Diagnostic objects
console.log(result.project); // Detected framework, React version, etc.

The diagnose function accepts an optional second argument:

const result = await diagnose(".", {
  lint: true, // run lint checks (default: true)
  deadCode: true, // run dead code detection (default: true)
});

Each diagnostic has the following shape:

interface Diagnostic {
  filePath: string;
  plugin: string;
  rule: string;
  severity: "error" | "warning";
  message: string;
  help: string;
  line: number;
  column: number;
  category: string;
}

Disclaimer

Vercel Doctor is not affiliated with, endorsed by, or sponsored by Vercel Inc., Vercel and the Vercel logo are trademarks of Vercel Inc. This is an independent, open-source project that review Next.js project code to help optimize Vercel costs.

Contributing

Want to contribute? Check out the codebase and submit a PR.

git clone https://github.com/Aniket-508/vercel-doctor
cd vercel-doctor
pnpm install
pnpm -r run build

Run locally:

node packages/vercel-doctor/dist/cli.js /path/to/your/nextjs-project

License

MIT