Encode & decode tools
Read what an encoded string actually says, and what it cost to get there.
Base64 Encoder & Decoder
Both directions, UTF-8 done right
Encode or decode base64 with the direction detected for you. Non-ASCII survives the round trip and both alphabets are handled.
Unix Timestamp Converter
Seconds or milliseconds? It says which
Convert a Unix timestamp or a date into every other representation, in UTC and your own timezone.
JWT Decoder & Inspector
Read the claims, and what is wrong with them
Decode a JWT header and payload in your browser, with every timestamp turned into a real date and a plain answer on whether it has expired.
URL Encoder and Decoder
Which of the two functions you actually want
Encode or decode a URL, and see the difference between encodeURI and encodeURIComponent that turns one query parameter into two.
HTML Entity Encoder and Decoder
Five characters, not four hundred
Encode or decode HTML entities, with the escaping context that decides whether five characters are enough or nowhere near.
Hex Encoder and Decoder
Bytes, with a hex dump
Convert text to hex or hex to text, with a byte dump, and the UTF-8 byte count that is not the character count.
Base32 Encoder and Decoder
Two alphabets that decode differently
Encode or decode base32 in both the RFC 4648 and Crockford alphabets, which overlap enough that one string is valid in both.
String Escape Converter
Six targets, one of them injection
Escape a string for JSON, JavaScript, shell, SQL, regex and CSV at once, including the shell quote that is command injection when written the obvious way.
Punycode and IDN Converter
The domain that is not what it looks like
Convert a domain between Unicode and punycode, and detect the mixed scripts that make one name render identically to another.