Two IP addresses, two completely different jobs
Your phone has not one IP address but two, and confusing them is why people follow instructions that show the 'wrong' number. The LOCAL IP (typically 192.168.x.x or 10.x.x.x) is assigned by your router and identifies your phone WITHIN your home network; it is what you need for casting to a TV, transferring files between devices, connecting to a printer, and ADB-over-Wi-Fi. The PUBLIC IP is the single address your entire home network shows to the INTERNET, assigned by your internet provider; it is what a website sees, what you would use for remote access, and what geolocation and 'what is my IP' services report.
The relationship is worth picturing: your router sits between them, holding one public IP on its internet side and handing out many private local IPs (one per device) on your home side, translating between them. So every device in your home shares the SAME public IP but has its OWN unique local IP. This is why the local IP you find in phone settings (192.168.something) looks nothing like the public IP a website reports, they are answering two different questions: 'which device on this network?' versus 'which network on the internet?'.
Knowing which you need saves confusion. Setting up casting, file sharing, a printer, or ADB over Wi-Fi: LOCAL IP, from phone settings. Configuring remote access, checking what the internet sees, or troubleshooting an IP ban or geo-block: PUBLIC IP, from a web lookup. Our device info tool shows connection details including network information, and the sections below give the exact steps for each, plus the practical problems that knowing your IP actually solves.
Finding your local IP address
The most reliable route: Settings, Network and internet (or Connections), Wi-Fi, tap the network you are connected to, and expand Advanced or Details, the IP address appears there, usually starting 192.168. On Samsung and some others the path is Settings, Connections, Wi-Fi, the gear icon next to your network, View more. If the menus differ on your phone, the fastest universal method is to open Settings and type 'IP address' into the search box at the top, which jumps you straight to it regardless of where your manufacturer buried it.
Two more places show it. Settings, About phone, Status information (or just Status) lists both the IP address and other network identifiers like the Wi-Fi MAC address, handy when you need several details at once. And our device info tool surfaces connection details in the browser. Note that your local IP is only meaningful while connected to Wi-Fi, on mobile data the 'local' concept differs (the carrier assigns addressing), which is one reason casting and local file sharing need Wi-Fi.
Understand that the local IP can change, which matters for setups that need to find your phone repeatedly. Routers assign local IPs via DHCP, and your phone may get a different one after reconnecting or rebooting. For things that must always reach your phone at the same address (a persistent file server, ADB over Wi-Fi you use often), you can make it static: in the Wi-Fi network's Advanced, IP settings, switch from DHCP to Static and set a fixed address within your router's range, or, better, reserve the phone's address in the router's DHCP settings so it always gets the same one. For a one-off cast or transfer, the current DHCP address from settings is all you need.
Finding your public IP address
The public IP is not in your phone's settings, because your phone does not own it, the router does. To see it, ask the internet: open any browser and search 'what is my IP', and the result at the top shows the public IP your network presents. Numerous sites report it, and the number is the same for every device on your home Wi-Fi at that moment, because they all share the router's single public address. This is the figure to use when a service says 'your IP is blocked' or when you need to know what the wider internet sees you as.
A crucial privacy caution: the public IP reveals your approximate location and your internet provider, so never post it publicly or paste it into untrusted sites, and be aware that this is exactly what a VPN changes, when a VPN is active, 'what is my IP' shows the VPN server's address and location instead of your real one, which is the whole point of a VPN for privacy and for accessing region-locked content. If your public IP looks like it is in another country, check whether a VPN is running before assuming something is wrong.
Public IPs also change and vary in type, which explains some networking surprises. Most home connections have a dynamic public IP that your provider rotates periodically, so the number you see today may differ next week, which is why remote-access setups often need dynamic-DNS services to track it. Some connections, especially mobile data and certain providers, use carrier-grade NAT, where many customers share one public IP, which can complicate remote access and is not something you can change from the phone. For most people the public IP is simply a thing to look up when a service asks, not something to configure.
Using IP knowledge to solve real problems
IP knowledge is practical, not academic. For casting and screen mirroring, the reason a Chromecast or TV does not appear is almost always that the phone and the device are on different networks or different Wi-Fi bands, confirm both have local IPs in the same range (both 192.168.1.x, say) and you have diagnosed the classic casting failure from our cast-to-TV guide. For local file transfer, printing, or connecting to a NAS, you type the target device's local IP into the app, and knowing your phone's own local IP confirms you are on the same network as the target.
For ADB over Wi-Fi, a genuinely useful trick for wireless debugging and the file access our screenshot and ADB guides describe, you connect the computer to the phone using the phone's LOCAL IP, which is why finding it (and optionally making it static) matters. For troubleshooting, an IP address starting with 169.254 is a red flag: it means the phone failed to get a real address from the router (a DHCP failure), and the fix is the network reset from our Wi-Fi guide, forget-and-rejoin, restart the router, or reset network settings, rather than anything to do with the internet itself. An IP that looks right but no internet points instead at DNS or a captive portal, also covered in the Wi-Fi guide.
Public-IP knowledge solves its own class of problems. A website or game that says your IP is banned, or that content is unavailable in your region, is reacting to your public IP, and a VPN (which changes it) is the tool, with the caveat that some services detect and block VPNs. If you are setting up remote access to something at home, you need the public IP plus router configuration, and likely dynamic DNS because it changes. And if 'what is my IP' unexpectedly shows a foreign country or a different provider, you have discovered an active VPN or proxy, useful to know when a VPN is silently breaking your other connections, exactly the VPN-as-culprit pattern our Wi-Fi, no-data and Android Auto guides flag. Knowing both your IPs turns a fog of networking mystery into a set of concrete, checkable facts.