Encoding & Crypto
Encode and decode Base64, URLs and HTML entities, inspect JWTs, and compute MD5, SHA and HMAC hashes or run AES encryption. Keys and content never leave your browser.
Tools in this category
Base64
Convert text to Base64 and back, with correct UTF-8 handling for accents, CJK and emoji. Runs entirely in your browser — nothing is uploaded.
URL Encode
Escape text into %XX form and back again, treating a whole URL and a single parameter value as different jobs. Runs entirely in your browser.
HTML Entities
Turn < > & and quotes into HTML entities and decode them back in a single pass, so &lt; becomes <, not an angle bracket. Runs in your browser.
JWT Decoder
Split a JWT into header, payload and signature, and read iat, nbf and exp as dates. The signature is not verified — decoding only, all in your browser.
Unicode Escape
Convert non-ASCII text and emoji into \uXXXX or \xXX escapes and back, with emoji written as proper surrogate pairs. Runs entirely in your browser.
Hash
Compute MD5, SHA-1, SHA-256 or SHA-512 digests of any text, hashed as UTF-8 bytes so they match openssl and sha256sum exactly. Runs in your browser.
HMAC
Sign a message with a secret key using HMAC and get a result matching Node, Java and Python. The key never leaves your browser — nothing is uploaded.