Network & Web
Tools for investigating networks and the web: subnet calculation, URL parsing and looking up HTTP status codes.
9 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.
Subnet Calculator
From an IPv4 address and CIDR/mask, compute the network, broadcast, host range, and host count.
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.
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.
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.
Filter Syntax Checker
Explains what each ad blocker filter line blocks, flags mistakes, and tests which rules match a URL.
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.