Text and numbers are encoded in many ways before they travel across the web, and some of them also protect it. These guides explain Base64, URL encoding, binary and hex, data units, hashes, passwords, unique IDs, tokens and permissions in plain language, with tools to try each one.
How to generate a UUID v7 in JavaScript, Python, .NET and PostgreSQL, why same-millisecond IDs need a counter, and a free generator that keeps them in order.
Password entropy explained: the formula, worked examples for random passwords and passphrases, what the bits mean in guesses, and where the maths breaks.
How to decode a JWT by hand and in code: the three parts, claims such as exp and iat, why decoding is not verifying, and a free private decoder.
How to convert binary to decimal with two hand methods, worked examples, hex and octal shortcuts, negative numbers and code, plus a free converter.
What does chmod 755 mean? The owner gets full access, others read and run. See octal digits, 755 vs 644, symbolic modes, setuid, sticky bits and umask.
How long should a password be? NIST says 15 characters at least when it is the only factor. See the math, passphrase options and a tested generator.
URL encoding special characters made clear: the full chart of reserved characters, %20 versus +, UTF-8 for accents and emoji, and how to avoid double encoding.
UUID v4 vs v7 explained: how each is built, how to read the timestamp in a v7, collision odds and which to pick for database keys and public IDs.
The Morse code alphabet and numbers in one chart, plus the ITU timing rules, the PARIS speed standard and how to write SOS correctly.
Base64 encoding turns bytes into text. See how it works step by step, why it adds 33%, URL-safe Base64 and why it is not encryption.
MD5 vs SHA256: which hash should you use? Get the short answer, the research behind it, a job-by-job guide and the commands to check a file hash.
Learn how to convert text to binary by hand and with a free tool, why é takes two bytes, how emoji differ, and how to decode binary back into text.
