Free tools for networks, domains and data
Run IP and DNS checks, plan IPv4 and IPv6 subnets, identify MAC vendors, and use practical browser-based file tools.
IPv4 Subnet Calculator
Calculate IPv4 network, broadcast, address range, wildcard mask and usable host count from a CIDR block.
Open toolIPv6 Subnet Calculator
Calculate the network prefix, address range and total address count for an IPv6 CIDR block, entirely in your browser.
Open toolIP Range to CIDR Converter
Convert an IPv4 start and end address into the smallest set of CIDR blocks that covers the range.
Open toolMAC Address Vendor Identifier
Identify a MAC address vendor automatically from a locally stored IEEE assignment registry.
Open toolIP Location & ISP Lookup
Find approximate location and ISP details for a public WAN address, with RDAP registration information when the location provider is unavailable.
Open toolDomain to IP & Reverse DNS
Check DNS A, AAAA and PTR records with a clear resolver disclosure before a lookup.
Open toolMy Public IP
Check the public IP address seen by an external service, only when you choose to run the check.
Open toolPercentage Change Calculator
Calculate the percentage increase or decrease between an original value and a new value, with the amount changed and the formula shown.
Open toolCSV Cleaner
Trim unwanted whitespace and remove empty rows from CSV data, with a change report before download.
Open toolExcel & CSV Compare
Compare two spreadsheets by a unique identifier and download a report of added, removed and changed records.
Open toolCSV & Excel Converter
Convert CSV data to an Excel worksheet or export one Excel worksheet as CSV while keeping identifiers as text.
Open toolMerge Spreadsheets
Combine Excel or CSV tables into one file by matching column headings, even when the column order differs.
Open toolSplit Spreadsheet
Split one CSV or Excel worksheet into smaller CSV files, repeating the header in every file.
Open toolSpreadsheet Duplicate Finder
Find repeated spreadsheet records using selected columns, then download unique rows and duplicate rows separately.
Open tool