A message appears, encoded in one of the schemes. Can you identify which one?
Data encoding schemes are foundational to computing, yet most developers only use a handful of them by rote. When you see a string of hex, Base64, or URL-encoded characters in logs, source code, or API responses, it is often unclear what scheme produced it. Encode Deck was built to demystify these schemes — making it easy to explore, compare, and practice identifying them by hand.
A card-based interactive explorer for 16 different data encoding schemes. Browse the gallery to learn about each scheme, encode and decode text in real-time, or test yourself in Challenge mode where you identify the encoding used in a given message. Covers fundamentals like Binary and Hex, web encodings like URL and HTML entities, communication formats like Morse code and Braille, and more.
Each encoding scheme is defined as a self-contained module with encode and decode functions. The Explorer mode renders each scheme as a card with a short description and sample output. Clicking a card opens a detail panel where you can type text and transform it. Challenge mode randomly picks a scheme and a sample message, encodes it, and presents it for identification. Scoring tracks correct answers, streaks, and total attempts.
Explore mode: Browse the card grid. Click any card to open its detail panel. Type text in the input box, then press "Encode" or "Decode" to transform it.
Challenge mode: Switch to the Challenge tab and press "Start Challenge." Read the encoded message, use "Show hint" if needed, then select the encoding scheme from the answer buttons. Your score and streak update after each answer.
Info button: Click the info icon in the header for this help panel. Close with the X button, clicking outside, or pressing Escape.