Hashes and base64
Base64 and base64url in both directions, and SHA-256, SHA-384 and SHA-512 digests as hex or base64 — computed by the browser, with decoding failures explained rather than thrown.
Encoded and hashed in your browser — nothing you paste is sent anywhere. Base64 is an encoding, not encryption: anyone who has the output can read the input back.
Text is read as UTF-8, then encoded with the standard alphabet.