Node.js Express Form Validation

Validate form data in Node.js Express using express-validator middleware chains, custom sanitizers, grouped error responses, and conditional validation.

Javascript Node Form Validation Updated: 2026-01-15

Code

snippet

import { body, validationResult } from 'express-validator';

export const validateLogin = [
  body('email').isEmail().normalizeEmail(),
  body('password').isLength({ min: 8 }).withMessage('Min 8 chars'),
  (req, res, next) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
      return res.status(400).json({ errors: errors.array() });
    }
    next();
  },
];