NetScope — Network & Web Tools
Subnets, status codes, URLs and campaign links — instant, private, free.
Runs 100% in your browser — nothing is ever uploaded.
All NetScope tools
How NetScope works
NetScope bundles the network lookups a developer reaches for a dozen times a day — subnet maths, HTTP status meanings, URL anatomy, campaign tagging, address conversion and live connectivity checks. Every calculation runs inside this page, so nothing you paste is transmitted, logged or retained.
Subnet and address maths, done locally
The CIDR calculator expands any prefix into its network address, broadcast address, usable host range and total host count, and the IP-to-binary converter shows the same address in binary, decimal and hexadecimal. Both are pure arithmetic, so they answer instantly and work identically whether you are planning a VPC, sizing a DHCP pool or reading a firewall rule.
Reading responses and URLs
The HTTP status reference explains what each code means in practice, when a server should send it and how clients and crawlers react — the difference between a 301 and a 302, or why a 503 is safer than a 500 during deploys. The URL parser splits any address into scheme, host, port, path, query parameters and fragment, decoding percent-encoding so malformed links and stray parameters become obvious.
Campaign links and live checks
The UTM builder assembles correctly encoded tracking links so analytics attributes traffic to the right source, medium and campaign instead of silently dropping it. The ping test and WebSocket tester open real connections from your own browser, which means they measure the path your users actually take, not the route from some distant data centre.
Why in-browser matters for network data
Internal hostnames, private ranges and staging URLs are exactly the details that should never be pasted into a stranger’s server. Because NetScope is static JavaScript with no backend, there is no upload step to trust and nothing to leak: the tools keep working with your network cable unplugged, and closing the tab is all the cleanup required.
NetScope FAQ
Are these network tools free?
Yes — every NetScope tool is 100% free with no signup, no limits and no ads walls.
Is my data uploaded anywhere?
No. All calculations (CIDR math, URL parsing, UTM building) run entirely in your browser. Nothing ever leaves your device.
Do these tools work offline?
Yes — once the page is loaded, the calculators work without an internet connection.
Can I use NetScope on private or internal addresses?
Yes, and that is the main reason it exists. Subnet, binary and URL tools are pure calculation, so RFC 1918 ranges like 10.0.0.0/8 or 192.168.1.0/24, internal hostnames and staging URLs are handled exactly like public ones — and never leave your browser. The ping and WebSocket testers are the one exception: they open a real connection, so they only reach hosts your own machine can already reach.
How accurate is the ping test compared with the ping command?
It measures something slightly different. A terminal ping sends ICMP packets, which browsers cannot emit, so NetScope times an HTTP request instead. The result therefore includes DNS resolution, the TLS handshake and the server’s own response time, and reads higher than ICMP. That makes it a good proxy for what a visitor experiences, but not a substitute for ICMP when you are diagnosing packet loss.
Do I need to install anything or sign in?
No. Every NetScope tool is plain JavaScript served with the page — no account, no extension, no CLI. Bookmark the tool you use most and it opens ready to work, on a phone, a locked-down work laptop or a machine where you cannot install software.