Free IP Address Lookup Online

What Is an IP Address Lookup Tool?

An IP address lookup tool is a utility that takes an IPv4 or IPv6 address, or a domain name, and returns publicly available network and geolocation data about it, including its approximate city, region, and country, its internet service provider, and its autonomous system number (ASN).

IP addresses themselves are defined by RFC 791 for IPv4 and RFC 8200 for IPv6, but neither standard includes location data. The city, ISP, and ASN details you see here come from public routing registries and geolocation databases, not from the addressing standard itself.

All processing happens in your browser. This IP address lookup tool is maintained by TestMu AI (formerly LambdaTest) as part of a free toolkit for developers, network engineers, and QA teams.

Related tools: What Is My IP Address and Reverse IP Lookup.

How Does This IP Address Lookup Tool Work?

When you enter an address, the tool first checks whether it is already a valid IPv4 or IPv6 address. If you entered a domain name instead, your browser resolves it to its current IP address using a public DNS-over-HTTPS resolver before the lookup continues.

The resulting IP address is then sent directly from your browser to a public IP geolocation API, which returns the country, region, city, ISP, ASN, and timezone data associated with that address. No TestMu AI server sits in the middle of this request, and no lookup history is stored.

How Do You Use the IP Address Lookup Tool?

Looking up an IP address takes a few seconds and no signup:

• Enter an address: Type an IPv4 address, an IPv6 address, or a domain name into the input field, or leave it blank.
• Look up or auto-detect: Click Look Up to check the address you entered, or click Use My IP to look up your own public IP address instantly.
• Review the results: See the location, ISP, ASN, and timezone details grouped into cards, along with a map of the approximate location.
• Copy or download: Copy any individual field with its Copy button, or download the full result as a JSON file for your records.

What Information Does an IP Address Lookup Show?

As a tool, IP address lookup surfaces several categories of publicly available network data. Here is what this lookup shows:

• Geolocation Details: Approximate continent, country, region, city, postal code, and map coordinates for the address.
• Network and ISP Data: The internet service provider, the owning organization, the connection domain, and the autonomous system number (ASN).
• Timezone Information: The IANA timezone ID, the current UTC offset, and whether daylight saving time is active.
• IPv4 and IPv6 Support: Automatic detection of the address format, so the same lookup works for both address types.
• Domain Resolution: Support for looking up a domain name directly, without first finding its IP address elsewhere.
• Exportable Results: A Copy All button for a plain-text summary and a Download JSON button for the complete raw response.

Why Would You Need to Look Up an IP Address?

Developers, network administrators, and QA teams reach for an IP lookup for several everyday tasks:

• Security Investigation: Check where a suspicious login, API request, or server log entry actually originated before deciding how to respond.
• Geo-Targeting QA: Confirm that region-based redirects, pricing, or content rules trigger for the right country before shipping a release. Pairing this with TestMu AI's real device cloud (10,000+ real devices and 3000+ browsers) lets you confirm the same geo-logic across real devices and locations, not just a single browser.
• Network Troubleshooting: Identify the ISP and ASN behind a connectivity issue, or confirm a server's outbound IP after a DNS or hosting migration.
• Abuse and Spam Review: Trace repeated form spam or scraping traffic back to an ISP or organization before adding a block rule.
• Domain Auditing: Verify which IP a domain currently resolves to, then cross-check it with the Domain to IP tool during a hosting or CDN change.

Frequently Asked Questions (FAQs)

What is an IP address lookup tool?

An IP address lookup tool takes an IP address or domain name and returns publicly available network details about it, such as its approximate city and country, its internet service provider, and its autonomous system number. It queries public registries and geolocation databases, not the device itself.

How accurate is IP address lookup?

Country-level accuracy is generally reliable, while city-level results can be off by tens of kilometers because they are inferred from how an ISP allocates address blocks, not from GPS. Mobile and VPN connections are usually the least precise.

Can an IP address lookup reveal my exact home address?

No. IP address lookup only exposes information tied to your internet provider's network, such as a nearby city or region, never a street address. Precise personal location data is not part of public IP registry or geolocation data.

Do I need the IP owner's permission to look up their IP address?

No. IP address lookup only returns information that is already public, such as registry and geolocation records, so no permission is required. It does not access private data on the device that uses that address.

Can I look up a domain name instead of an IP address?

Yes. Enter a domain name, such as example.com, and the tool resolves it to its current IP address using public DNS before running the same lookup, so you do not need to find the IP address yourself first.

What does ASN mean in the lookup results?

ASN stands for Autonomous System Number, a unique identifier assigned to a network operator such as an ISP or cloud provider. It shows which organization actually routes traffic for an IP address, which is more precise than the ISP name alone.

Why does my IP lookup show a city different from where I actually am?

Geolocation databases map an IP address to the location where an ISP registered that address block, which is often a regional hub rather than your exact city. Mobile networks, VPNs, and corporate proxies commonly show a nearby, incorrect city for this reason.

Is this IP address lookup tool free to use?

Yes, the IP address lookup tool is completely free, with no signup, login, or lookup limit. It is maintained by TestMu AI (formerly LambdaTest) as part of a free developer and QA toolkit.

Does this tool store or log the IP addresses I search?

No. The lookup runs directly from your browser to the DNS and geolocation providers, and TestMu AI does not receive, store, or log the addresses you search through this page.

Can I look up an IPv6 address with this tool?

Yes. Paste a full IPv6 address, such as 2001:4860:4860::8888, and the tool detects the format automatically and returns the same location, ISP, and timezone details it returns for IPv4 addresses.

Can IP address lookup detect if someone is using a VPN or proxy?

This free lookup shows the ISP and network operator for the address you enter, but it does not include a dedicated VPN or proxy detection flag. A commercial or hosting-provider ISP name is often the clearest hint that an address belongs to a VPN or data center.