My IP Check
Your public IP address and network location, detected automatically.
Loads automatically when you open NetChecks — no input needed. Use the Refresh button to re-check after switching networks or reconnecting your VPN.
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All-in-One Scan
Runs every relevant check against one IP or hostname in a single pass: DNS, whois, ping, traceroute, a well-known-ports scan (1-1024), HTTP headers and the SSL certificate.
Enter a domain or IP address and run it to check DNS, whois, ping, traceroute, common ports, HTTP headers, and the SSL certificate all at once.
Most checks run in parallel - typically finishes in about 30 seconds, longer if the target is slow or unreachable.
The port scan step only runs once the consent checkbox above is checked - every other check runs regardless.
Ping
Send ICMP echo requests to a host to check reachability and latency.
Enter a hostname or IP address and press Ping to send ICMP echo requests and measure round-trip latency.
Traceroute
Trace the network path (hop by hop) to a destination host.
Enter a hostname or IP address and run it to see every network hop between this server and the destination, with latency per hop.
DNS Lookup (Nslookup)
Query DNS records: A, AAAA, MX, TXT, NS, CNAME, SOA, PTR, SRV, CAA.
Enter a domain, choose a record type (A, AAAA, MX, TXT, NS, CNAME, SOA, PTR, SRV, or CAA), then look it up.
Whois
Look up registration information for a domain or IP address.
Enter a domain or IP address to look up its registration details — registrar, owner organization, and important dates.
Blacklist Check
Check whether an IP address or domain is listed on public spam/abuse blocklists (DNSBL).
Enter an IPv4 address or domain and run it to check 7 public DNSBL/RBL blocklists at once - each shows as listed, not listed, or check failed.
TCP Port Scan
Check whether TCP ports are open on a host or IP: common ports, a custom list, or the full 1-65535 range.
Enter a host or IP, pick common ports, a custom list, or the full range, then scan to see which TCP ports respond.
A full range scan can take up to ~100 seconds. Large scans (more than 100 ports, including custom ranges/lists) are limited to 1 per minute per visitor.
Open ports (0)
HTTP Header Inspector
Fetch the HTTP response status and headers for a URL.
Enter a URL to fetch its HTTP response status code and every response header the server sends back.
SSL / TLS Certificate Checker
Inspect a host's TLS certificate: issuer, validity dates, and days remaining.
Enter a hostname to inspect its TLS certificate — issuer, validity dates, and days remaining before it expires.
Geo-IP Lookup
Look up the geographic location and network info for an IP address. Leave empty to look up your own public IP.
Enter any IP address, or leave it empty to look up your own, to see its approximate location and network/ISP info.
Learn more about Geo-IP Lookup
What it is
GeoIP Lookup geographically locates an IP address and simultaneously identifies the ASN (Autonomous System Number) it belongs to - in other words, the telecom carrier or network provider that actually operates that address range on the internet.
How it works
Geographic location relies on databases built from allocation records published by the regional internet registries, supplemented by network observations collected continuously. ASN identification, on the other hand, comes directly from public BGP (Border Gateway Protocol) routing tables, a mechanism that is structurally far more reliable and up to date than geolocation itself, since it reflects the actual routing announcement rather than a statistical estimate.
Reading the results
The returned country is generally reliable and rarely proves wrong. City-level accuracy is far less reliable, particularly for mobile IP addresses, VPN traffic, or those belonging to a large cloud provider, where the address may be registered at the operator's administrative headquarters rather than the end user's actual physical location - a gap of several hundred kilometers is nothing unusual there. The ASN, by contrast, reliably and verifiably identifies who actually operates the network in question, whether a consumer telecom carrier, a hosting provider, or a business running its own independent address block.
Common mistakes
A common mistake in a security context is relying exclusively on approximate geolocation to make a blocking or trust decision, when this information is easily circumvented (VPN, proxy, Tor) and was never designed as a reliable security mechanism - it gives a useful lead for investigation, not evidence to rely on by itself. Another trap: forgetting that a single ASN can cover several countries or continents for large international carriers and global cloud providers, which makes the assumption "one ASN = one country" sometimes misleading.
When to use it
Quickly identifying the likely origin of suspicious traffic or an intrusion attempt, as a first step before a deeper investigation. Checking which geographic point of presence (PoP) of a CDN actually served a given request, to diagnose a localized performance issue. Diagnosing an unexpected geo-block applied by a third-party service by confirming exactly which country is actually being detected for the address concerned. Unambiguously confirming the network operator responsible for an address range before formally contacting them about an abuse report.
Subnet / CIDR Calculator
Computed entirely in your browser — no data sent to the server.
Enter an IP address and CIDR prefix (e.g. 192.168.1.0/24) to instantly compute the network range, broadcast address, and usable host count.
Speed Test
Basic download/upload throughput test against this server (accuracy depends on the server's own uplink).
Press Start to measure download and upload throughput against this server. Accuracy depends on this server's own connection.
Country Code Dictionary
ISO 3166-1 alpha-2 country codes — searched entirely in your browser.
Search or browse the list of ISO 3166-1 alpha-2 country codes, looked up entirely in your browser.
| Country | ISO Code |
|---|
Phone Dialing Code Dictionary
International calling codes by country — searched entirely in your browser.
Search or browse international calling codes by country, looked up entirely in your browser.
| Country | Dial Code |
|---|
World Clock
Pick a time zone to see the current time — drag the globe to spin it.
Pick a time zone from the list, or drag the globe, to see the current time there.
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Drag to rotate the globe.
French Mobile Network Status
Mobile antenna sites down or under maintenance in France, by operator (Orange, Free, SFR, Bouygues Telecom), from ARCEP's public data. Snapshot updated once a day by ARCEP - not a minute-by-minute feed.
Browse mobile antenna and fibre outage data by French operator — no input needed, updated automatically from ARCEP's public data.
Most affected departments
Number of sites currently down or under maintenance, by department. Click an operator above to filter.
Data: Arcep — Sites indisponibles · Official network status map
Fixed Network (Fibre)
Fibre (FTTH) network quality by operator: reported-outage rate and connection-failure rate, from ARCEP's public data. Monthly indicators, 6-month rolling average - not a live feed like the mobile section.
By operator (parent group)
Averages over the last 6 available months, per infrastructure-operator parent group.