Network & hardware

Check whether an IP address belongs to a known VPN provider or datacenter network.

Check how old a domain name is by looking up its WHOIS registration date. See the exact age in years, months, and days, along with registrar and expiry details.

Check when a domain name will expire, including days remaining, registrar, and registration dates.

Check whether a domain name is available to register or already taken. Runs a live WHOIS lookup and shows registrar, creation, and expiry details when the domain is registered.

Identify the web server software running on a host via a GET request to its index page.

Enter a website URL and the server fetches and validates its robots.txt, showing sitemaps, crawl delay, and preferred host.

Fetch a page and check its hreflang tags for missing x-default, invalid language codes, duplicates, and self-referencing errors.

Connect to a host and port to inspect its TLS/SSL certificate — expiry, trust status, full chain, protocol, and cipher suite.

Look up RDAP registration data for any domain, including registrar, registrant, nameservers, and expiry date.

Validate a domain's SPF, DKIM, and DMARC DNS records to check email authentication and spot misconfigurations.

Select a file to see how long it will take to upload at your internet speed. Reads the exact file size in your browser and estimates the upload time for any speed unit, from Mbps to MB/s.

Select a file to see how long it will take to download at your internet speed. Reads the exact file size in your browser and estimates the download time for any speed unit, from Mbps to MB/s.

Generate the daemon.json settings that control which subnets Docker uses: default-address-pools and the docker0 bridge address (bip). See how many networks fit into your ranges and check for clashes.

Edit a Cookie or Set-Cookie header in a form. Change names, values, and attributes like Domain, Expires, SameSite, and Secure, and get the updated string with warnings for common mistakes.

Build a compose.yaml for Uptime Kuma. Choose the image version and variant, ports, data location, Docker monitoring, and a SQLite or MariaDB database, and get a file that is ready to run.

Build a compose.yaml for Syncthing. Choose host or bridge networking, the GUI address, user and group, storage, and extra folders, and get a file with a matching health check.

Build a compose.yaml for Jellyfin. Choose the official or LinuxServer.io image, ports and networking, media folders, and Intel, AMD, or NVIDIA hardware acceleration, and get a file that is ready to run.

Edit your hosts file in a form. Add, remove, and switch entries on or off, get warnings for invalid addresses, wildcards, and duplicate hostnames, and download the result or restore the Windows, macOS, or Linux default.

Test the stereo balance of your headphones or earbuds. Check that left and right are the right way round, find where the sound is centered to see which side is quieter, and follow a sweep from ear to ear, with test sounds or your own audio file. Runs in your browser.

Enter a URL and the server fetches the page, extracts every JSON-LD structured data block, and checks it for JSON syntax errors, missing @context and @type, unknown schema.org types and properties, and fields Google needs for rich results.

Check whether a hostname or website is on the StevenBlack hosts blocklist, the full list with adware, malware, fake news, gambling, porn, and social media domains.

Check whether a hostname or website is blocked by HaGeZi's Multi ULTIMATE DNS blocklist, the largest tier with ads, trackers, telemetry, phishing, malware, and scams, and see which entry blocks it.

Check whether a hostname or website is blocked or targeted by EasyList, EasyPrivacy, and Fanboy's Annoyance List, and see every filter that blocks it, hides elements on it, or allows it.

See how far a website or IP address is from you on a map. The tool resolves the domain's IP addresses over DNS, geolocates each server, and shows the distance and the theoretical minimum ping from your location.