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Home/Best tools/Free Network & Web Tools

Best Free Network & Web Developer Tools

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.

URL ParserBreak any URL into protocol, host, port, path, query string and hash instantly in your browser using the native URL API.Query String to TablePaste a URL query string and see every parameter listed as clean key and value rows, decoded and easy to read, in your browser.Query String BuilderEnter key and value pairs and get a correctly URL encoded query string ready to append to any link, built in your browser.URL Query Value EncoderPercent encode a single value for safe use in a query string, or decode one back, all in your browser.CIDR CalculatorEnter an IPv4 CIDR block and get the network address, broadcast, usable host range, subnet mask and total host count instantly.Subnet Mask CalculatorPick a CIDR prefix and see the matching dotted decimal mask, wildcard mask, binary form and host count, all in your browser.CIDR to Netmask ConverterTurn a CIDR prefix like /26 into its dotted decimal subnet mask and back again instantly, all in your browser.Netmask to CIDR ConverterPaste a dotted decimal subnet mask and get its CIDR prefix length, with validation for contiguous masks, in your browser.IPv4 Range CalculatorEnter a start and end IPv4 address and get the exact number of addresses in the inclusive range, all computed in your browser.IP to Integer ConverterTurn a dotted decimal IPv4 address into its single 32-bit unsigned integer, and convert an integer back to an IP, in your browser.IP to Binary ConverterSee any IPv4 address as its 32-bit binary form, octet by octet, plus hex and integer, all computed instantly in your browser.IPv4 and IPv6 ValidatorCheck whether a string is a valid IPv4 or IPv6 address and see its type, class and whether it is private, all in your browser.IPv6 Expander and CompressorExpand a shortened IPv6 address to its full form or compress a long one to the shortest valid form, in your browser.MAC Address FormatterNormalize a MAC address and convert it between colon, hyphen, dot and bare hex separators, uppercase or lowercase, in your browser.User Agent ParserPaste any browser user agent string and read the likely browser, engine, operating system and device type, all parsed in your browser.HTTP Status Code LookupSearch every standard HTTP status code by number or name and read its meaning and category, all offline in your browser.HTTP Header ReferenceSearch common request and response headers and read what each one does, whether offline in your browser, no lookups needed.MIME Type LookupFind the correct Content-Type for any file extension, or search by type, instantly and offline in your browser, no server needed.Well Known Ports LookupSearch common TCP and UDP ports by number or service name and see what each one is used for, offline in your browser.DNS Record Types ReferenceSearch common DNS record types like A, AAAA, MX and TXT and read what each one does, offline in your browser.WHOIS Lookup Link BuilderEnter a domain and get ready to open WHOIS and DNS lookup links for several services, built entirely in your browser.Punycode Domain ConverterTurn an international domain name into its ASCII punycode form and back, using the browser URL engine, all offline in your browser.

Frequently asked questions

Are these tools free?

Yes. Every tool in this toolkit is completely free, with no sign-up and no usage limits.

Do these tools work on mobile?

Yes. They run in any modern web browser on phone, tablet or desktop, with nothing to install.

Is my data private?

Yes. These tools run entirely in your browser, so nothing you enter is uploaded to a server.

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