What's My IP: Finding Your Public IP Address

What Your Public IP Address Is

Your public IP address is the address that external servers see when your device connects to the internet. It is assigned by your ISP or hosting provider and is routable on the global internet. This is different from your private IP address (typically in the 10.x.x.x, 172.16-31.x.x, or 192.168.x.x ranges), which only exists within your local network.

Most home and office networks use NAT (Network Address Translation): many devices share a single public IP address. When you check your IP with the mxio What's My IP tool, you see the NAT gateway's public address — the one the rest of the internet uses to reach you.

Why Your Public IP Matters

Email Reputation

Mail servers are identified by their IP addresses. When your server sends email, the receiving server checks the sending IP against reputation databases and blacklists. A blacklisted IP means your email gets rejected or filtered to spam — regardless of how well your SPF, DKIM, and DMARC are configured. If your IP has been listed, see the blacklist delisting guide for steps to resolve it.

Reverse DNS (PTR Records)

Receiving mail servers often check whether the sending IP has a valid PTR record — a reverse DNS entry that maps the IP address back to a hostname. Missing or mismatched PTR records are a common cause of email delivery failures, especially with strict receivers like Microsoft 365. Use the PTR Lookup tool to verify your IP's reverse DNS is configured correctly. For details on why this matters, see Missing PTR Record.

IP Geolocation

Your public IP address reveals your approximate geographic location. The IP Geolocation tool shows what location databases associate with any IP address. This matters for services that use IP geolocation for fraud detection, content localization, or regulatory compliance.

Public vs. Private IP Addresses

If you run ipconfig or ifconfig and see a 192.168.x.x address, that is your private address. Your public address is the one the What's My IP tool returns — the address that external servers use to identify your connection.

Checking Your IP

Use the mxio What's My IP tool to instantly see your public IP address. From there, check your reverse DNS, geolocation, and blacklist status to get the full picture of your IP's reputation and configuration.

Find your public IP address