Free Internet Tools — DNS Lookup, Speed Test and More

DNS (Domain Name System) translates human-readable domain names like toolboxhubapp.com into the IP addresses that computers use to connect. A DNS lookup retrieves the records associated with a domain — A records (IPv4 addresses), AAAA records (IPv6), MX records (mail servers), CNAME records (aliases), TXT records (verification strings), and more. DNS lookups are useful when troubleshooting email delivery issues, verifying that DNS changes have propagated, confirming domain ownership records, and diagnosing connectivity problems.

Open the Website Speed Test tool, enter your URL, and run the test. The tool measures how long the page takes to load and reports key performance metrics. Slow load times hurt both user experience and search engine rankings — Google uses page speed as a ranking signal for both desktop and mobile searches. Common causes of slow pages include uncompressed images, unminified CSS and JavaScript, slow server response times, and too many external resource requests.

The Mobile Friendly Checker tests whether a web page is usable on a smartphone screen. It checks whether the page uses a responsive layout that adapts to small screens, whether tap targets (buttons, links) are large enough to use with a finger, whether text is readable without zooming, and whether the page avoids horizontal scrolling. Google's mobile-first indexing means a page's mobile version is the one used for ranking, so passing this check is important for SEO.

The URL Redirect Checker follows a URL through every HTTP redirect in the chain and shows each step with its HTTP status code. A 301 redirect is a permanent redirect, a 302 is temporary, and a 307 is a temporary redirect that preserves the request method. Checking redirect chains is useful for diagnosing broken links, verifying that old URLs are pointing to the correct new destinations, and auditing site migrations where hundreds of redirects were set up.

A User Agent string is a line of text that your browser sends to every website you visit, identifying the browser name, version, operating system, and rendering engine. Websites use this to serve appropriate content, track browser usage, and block certain automated clients. The User Agent Parser on Toolbox Hub breaks the string into its components and displays them in plain English — useful for debugging browser-specific issues, checking what a custom client reports, and understanding web analytics data.

HTTP status codes are three-digit numbers that a server returns with every response to tell the browser (or API client) what happened. 200 means success. 301 and 302 are redirects. 400 means a bad request, 401 means unauthorised, 403 means forbidden, 404 means the page was not found. 500 is a server error, 502 is a bad gateway, and 503 means the service is temporarily unavailable. Knowing what each code means is essential for debugging websites, APIs, and crawl issues flagged in tools like Google Search Console.

A MIME type (Multipurpose Internet Mail Extensions type) is a label that tells a browser or server what kind of data a file contains. For example, image/jpeg tells the browser a file is a JPG image, application/json tells an API client the response is JSON, and text/html tells the browser the content is an HTML page. MIME types are set in HTTP response headers and are important for file uploads, API responses, and any system that needs to handle different file types correctly. The MIME Type Lookup tool shows the correct MIME type for any file extension.