Free Content-Type Header Checker

Nginx

# Send correct MIME types from /etc/nginx/mime.types
include       mime.types;
default_type  application/octet-stream;

# Force UTF-8 on text responses
charset utf-8;
charset_types text/html text/css text/plain application/javascript application/json;

# Block MIME-sniffing
add_header X-Content-Type-Options "nosniff" always;

Apache

# Ensure mod_mime is enabled and types are correct
AddType application/json .json
AddType text/css .css
AddType application/javascript .js

# Default charset for text responses
AddDefaultCharset utf-8

# Block MIME-sniffing
Header always set X-Content-Type-Options "nosniff"

Node.js (Express + Helmet)

import express from "express"
import helmet from "helmet"

const app = express()

// Sets X-Content-Type-Options: nosniff
app.use(helmet.noSniff())

app.get("/api/data", (req, res) => {
  // Always set an explicit Content-Type with charset for text payloads
  res.type("application/json; charset=utf-8").send({ ok: true })
})