mkcert + Vite & Next.js : HTTPS local (2026)

brew install mkcert
mkcert -install
mkdir -p certs
mkcert -cert-file certs/local-cert.pem -key-file certs/local-key.pem \
  localhost 127.0.0.1 ::1 monprojet.test "*.monprojet.test"

127.0.0.1 monprojet.test
127.0.0.1 api.monprojet.test

// vite.config.js
import { defineConfig } from 'vite';
import fs from 'fs';
import path from 'path';

const certDir = path.resolve(__dirname, 'certs');

export default defineConfig({
  server: {
    host: 'monprojet.test',
    port: 5173,
    https: {
      key: fs.readFileSync(path.join(certDir, 'local-key.pem')),
      cert: fs.readFileSync(path.join(certDir, 'local-cert.pem')),
    },
  },
});

next dev --experimental-https \
  --experimental-https-key ./certs/local-key.pem \
  --experimental-https-cert ./certs/local-cert.pem

{
  "scripts": {
    "dev": "next dev --experimental-https --experimental-https-key ./certs/local-key.pem --experimental-https-cert ./certs/local-cert.pem"
  }
}