Network & Web
Tools for investigating networks and the web: subnet calculation, URL parsing and looking up HTTP status codes.
13 tools・Ordered by measured page views over the last 90 days.
Browser Info Viewer
A free tool that shows your browser type and version, screen/window size, IP, language, time zone, GPU, and more, all on one screen.
Network Segment Designer
Assemble network segments as blocks and see parent-child relationships and IP ranges as a diagram. Overlaps and out-of-range CIDRs are flagged, and the design exports as Markdown.
URL Parser
Break a URL into protocol, host, path, query parameters and hash. Parameters are percent-decoded and listed.
HTTP Status Codes
Look up what 200, 301, 401, 403, 404, 429 and 502 mean by number or name, with notes on 401 vs 403 and 301 vs 302.
Filter Syntax Checker
Explains what each ad blocker filter line blocks, flags mistakes, and tests which rules match a URL.
Subnet Calculator
From an IPv4 address and CIDR/mask, compute the network, broadcast, host range, and host count.
Punycode Converter
Convert internationalized domain names to and from Punycode (xn--) notation. Shows the result label by label and flags labels over the 63 octet limit.
MAC Address Generator and Formatter
Bulk-generate MAC addresses for testing and convert between colon, hyphen, Cisco dotted and plain notation. Locally administered bit and fixed OUI supported.
IPv6 Address Expander and Compressor
Convert IPv6 addresses between abbreviated and expanded form and normalize to the RFC 5952 recommended representation. Computes the network address and range from a prefix length.
Documentation IP Generator
Generate values that standards reserve for documentation, so nothing pasted into a runbook can reach production. Covers IPv4 (RFC 5737), IPv6 (RFC 3849), domains (RFC 2606), AS numbers (RFC 5398) and MAC addresses (RFC 7042).
Meta Tag and OGP Generator
Generates title, description, canonical, OGP and Twitter card tags from one form, with search and social previews plus length and absolute-URL checks.
robots.txt Generator
Build a robots.txt from Disallow, Allow, Sitemap and Crawl-delay lines. Tests whether a path would be crawled and flags common mistakes.
Cache-Control Analyzer
Explain each directive and show freshness for the browser cache and shared caches, plus conflicts.