The networking and web utilities you keep googling. Calculate subnets and CIDR ranges, parse and build URLs and query strings, convert IP formats, and look up HTTP status codes, MIME types and ports. All client-side with no server calls, so it is fast and private. All 22 tools below are free, run in your browser, and need no sign-up.
Free online URL parser. Break any URL into protocol, host, port, path, query string and hash instantly in your browser using the native URL API.
Free query string parser. Paste a URL query string and see every parameter listed as clean key and value rows, decoded and easy to read, in your browser.
Free query string builder. Enter key and value pairs and get a correctly URL encoded query string ready to append to any link, built in your browser.
Free URL query value encoder and decoder. Percent encode a single value for safe use in a query string, or decode one back, all in your browser.
Free CIDR calculator. Enter an IPv4 CIDR block and get the network address, broadcast, usable host range, subnet mask and total host count instantly.
Free subnet mask calculator. Pick a CIDR prefix and see the matching dotted decimal mask, wildcard mask, binary form and host count, all in your browser.
Free CIDR to netmask converter. Turn a CIDR prefix like /26 into its dotted decimal subnet mask and back again instantly, all in your browser.
Free netmask to CIDR converter. Paste a dotted decimal subnet mask and get its CIDR prefix length, with validation for contiguous masks, in your browser.
Free IPv4 range calculator. Enter a start and end IPv4 address and get the exact number of addresses in the inclusive range, all computed in your browser.
Free IP to integer converter. Turn a dotted decimal IPv4 address into its single 32-bit unsigned integer, and convert an integer back to an IP, in your browser.
Free IP to binary converter. See any IPv4 address as its 32-bit binary form, octet by octet, plus hex and integer, all computed instantly in your browser.
Free IP address validator. Check whether a string is a valid IPv4 or IPv6 address and see its type, class and whether it is private, all in your browser.
Free IPv6 expander and compressor. Expand a shortened IPv6 address to its full form or compress a long one to the shortest valid form, in your browser.
Free MAC address formatter. Normalize a MAC address and convert it between colon, hyphen, dot and bare hex separators, uppercase or lowercase, in your browser.
Free user agent parser. Paste any browser user agent string and read the likely browser, engine, operating system and device type, all parsed in your browser.
Free HTTP status code reference. Search every standard HTTP status code by number or name and read its meaning and category, all offline in your browser.
Free HTTP header reference. Search common request and response headers and read what each one does, whether offline in your browser, no lookups needed.
Free MIME type lookup. Find the correct Content-Type for any file extension, or search by type, instantly and offline in your browser, no server needed.
Free port number lookup. Search common TCP and UDP ports by number or service name and see what each one is used for, offline in your browser.
Free DNS record types reference. Search common DNS record types like A, AAAA, MX and TXT and read what each one does, offline in your browser.
Free WHOIS lookup link builder. Enter a domain and get ready to open WHOIS and DNS lookup links for several services, built entirely in your browser.
Free punycode converter. Turn an international domain name into its ASCII punycode form and back, using the browser URL engine, all offline in your browser.
Yes. Every tool in this toolkit is completely free, with no sign-up and no usage limits.
Yes. They run in any modern web browser on phone, tablet or desktop, with nothing to install.
Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.