Encoders and classical ciphers: Base64, Base64URL, Base32, Base36, Base58, binary, hex, URL encoding, Unicode escapes and HTML entities, plus Morse code, ROT13, Caesar cipher and a JWT decoder. Every tool works in both directions, and Base64 goes through a UTF-8 path so non-ASCII text survives the round trip. All of it runs offline.
Base64 represents binary data with 64 printable characters, so binary can travel through text-only protocols. Encode: encodes any data into strings of the 64 characters A-Z, a-z, 0-9, + and / Decode: restores the original data from a Base64 string URL-safe mode: replaces + with -, / with _, and drops the = padding
URL (percent) encoding turns special characters into %XX form so the URL transmits safely. Encode: escapes with encodeURIComponent Decode: restores with decodeURIComponent Letters, digits and the safe characters -_.!~*'() are preserved
Base32 uses the 32 characters A-Z and 2-7, useful where case is unreliable. Follows RFC 4648 Every 5 bits of data map to one character Easier to transcribe and read aloud than Base64
Base36 uses 36 characters (0-9, a-z) as a compact way to write numbers. Supports BigInt for very large numbers Encode: decimal number to Base36 string Decode: Base36 string to decimal number
Base58 is the encoding behind Bitcoin addresses; it drops the easily confused characters 0OIl. Alphabet: 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz Leading zero bytes map to the character 1 Common for blockchain addresses and short URLs
Base64URL is the URL-safe variant of Base64, used by JWTs and other values that travel in a URL. Replace + with - Replace / with _ Drop the trailing = padding
Binary decoding turns a sequence of 0s and 1s back into text. Each group must be 8 binary digits Separate groups with spaces
Binary encoding converts text into 0/1 sequences: each character becomes 8 bits of UTF-8. Encode: text to 8-bit binary, space separated Decode: 8-bit groups to text
The Caesar cipher shifts each letter by a fixed number of positions. Shift range: -25 to 25 Only letters are processed; everything else stays as it is ROT13 is the Caesar cipher with a shift of 13
Hex decoding turns a hexadecimal string back into text. The input length must be even Blank characters are stripped automatically
Hex encoding writes each byte as two hexadecimal characters (0-9, a-f), handy for debugging and data work. Encode: text to a continuous hex string Decode: hex string to text (the length must be even)
HTML entity encoding turns special characters into safe entity references. Encode: turns < > & " into entities Decode: turn entities back into characters Covers 37 common HTML entities
Decodes a JWT header and payload and shows the expiry — locally, so the token is never sent anywhere.
Morse decoding turns dots and dashes back into text. Separate letters with spaces / means a space
Morse code represents characters as combinations of short (·) and long (-) signals. Covers A-Z, 0-9 and 8 punctuation marks Use / for a space Separate characters with spaces
ROT13 is a simple substitution that replaces each letter with the one 13 places after it. Only letters are processed; everything else stays as it is Self-inverse: apply it again to restore the text Often used to hide spoilers or lightly obfuscate text
Unicode escaping writes characters in the \uXXXX form, common in JSON and JavaScript. BMP characters (U+0000 to U+FFFF) become \uXXXX Supplementary-plane characters (such as emoji) become \u
Unicode unescaping turns \uXXXX sequences back into readable text. Supports the \uXXXX form Supports the \u format (characters beyond the BMP)
