Technology & Internet Tools13 free tools for developers, network admins, and everyday internet users: a subnet/CIDR calculator, a secure password generator, a bandwidth/download-time calculator, Base64 and URL encoder/decoders, a HEX/RGB color converter, a JSON formatter, a UUID generator, an MD5/SHA hash generator, and a screen size & aspect ratio calculator. Everything runs locally in your browser — nothing is ever uploaded.
Calculate network address, broadcast address, usable host range, subnet mask, and number of hosts from any IPv4 address and CIDR prefix.
Generate strong, random, hard-to-guess passwords instantly using your browser's secure random number generator — fully customizable length and character types.
Estimate how long a file will take to download (or upload) based on its size and your internet connection speed.
Encode any text into Base64 format, or decode a Base64 string back into readable text — instantly, right in your browser.
Encode text or a full URL into a safe percent-encoded format, or decode a percent-encoded URL back into readable text.
Convert colors instantly between HEX code and RGB values, with a live color preview swatch.
Beautify (pretty-print) or minify any JSON text instantly, with clear error messages if the JSON is invalid.
Generate one or many random Version 4 UUIDs (universally unique identifiers) instantly, using your browser's secure random generator.
Generate MD5, SHA-1, SHA-256, and SHA-512 hash digests of any text instantly, all calculated locally in your browser.
Calculate a screen's aspect ratio (like 16:9) from its resolution, and optionally its physical diagonal size in inches and centimeters if you know its pixel density (PPI).
Estimate the uncompressed file size of an image, audio clip, or video based on its technical parameters.
Convert between bits, bytes, kilobytes, megabytes, gigabytes, and terabytes, using either decimal (1000-based) or binary (1024-based) units.
Generate a scannable QR code from any text, URL, or message — created entirely in your browser using a hand-built QR encoding engine, with no external service involved.