Internet Toolkit

Update Check

An online service to help Windows users check installed programs are up to date and do not have known security vulnerabilities. more...

Antivirus

Malware in email und Internet pages are now everyday occurences. On our antivirus pages you can find tips on how to how to protect your system, links to free and commercial antivirus software, and advice on how to rid your system of these microbes. more...

Browsercheck

Surfing is certainly easier using JavaScript, ActiveX und Co, but because of bugs and bad configuration browsers are unsafe. With the heisec Browsercheck you can test out and improve your browser configuration. more...

Emailcheck

More and more viruses and phishing-mails are delivered with your email. The test emails of our Emailcheck show you how to keep your computer clean. more...

Conficker test

The Conficker test is a quick, in-browser test to help you check for Conficker infection. more...

Test SSL certificates

Test here whether your site's https key is insecure because of an error in OpenSSL. more...

Whois query

The whois service supplies information on the owners of IP addresses and domain names. more...

My IP address

This shows the IP address from which your browser is accessing this website; this is either the address of your computer, your router or your proxy. more...

Traceroute

This tool shows the route taken by IP packets between h-online.com and any IP address or host name that you provide. more...

DNS query

The DNS query provides the IP address of a computer, plus much additional information. more...

Subnet calculator

This computes subnet masks, broadcast addresses or CIDR suffixes for an IPv4 subnet. Also the smallest common subnet for two IPv4 addresses. more...

MAC addresses

This tool determines the manufacturer of your network adaptor, once you enter the adaptor MAC address. more...

RFCs

full text search and direct access to all current requests for comments regarding internet standards and other issues. more...

Ping

The ping tool checks the availability of a computer on a network from www.h-online.com. more...

Bandwidth calculator

Tells you if there enough free capacity for your file-sharing and other bandwidth intense applications. more...

Spam list query

This enables you to check whether an email address is on one of the blacklists used by spam blockers. more...

IP addresses

an overview of all reserved IPv4 addresses. more...