Base64URL Encoder Online

Create a Base64URL representation of text containing ordinary letters, Hindi, emoji or other Unicode characters. The encoder first produces UTF-8 bytes, then uses the URL-safe Base64 alphabet. Choose whether your destination expects trailing equals-sign padding before copying the result.

Encode a message step by step

Paste the text, choose the padding option and select Convert. For the input Hi, unpadded output is SGk and padded output is SGk=. Copy the exact result into your development example or save it as a text file. A leading or trailing space in the input is meaningful and changes the output, so remove accidental whitespace before encoding.

Understand the URL-safe alphabet

Base64URL changes two characters from the standard Base64 alphabet: hyphen replaces plus and underscore replaces slash. This is useful where those standard characters have another meaning in URLs or filenames. The converter encodes a text payload; it does not percent-encode an entire URL, build a signed link or decide which parameters your destination service requires.

Match the expected padding convention

Base64 represents groups of bytes using groups of encoded characters. A partial final group may need one or two equals signs. Some Base64URL consumers omit that padding, while others expect it. Select the convention specified by your receiving system. Padding changes the representation, not the decoded message; both SGk and SGk= represent Hi when interpreted by a compatible decoder.

Keep encoding separate from authentication

Anyone who receives the string can decode its contents. Base64URL is used inside several token formats, but this tool does not sign, encrypt or authenticate a token. It accepts text rather than arbitrary binary files and supports up to 100,000 input characters. For a complete JWT, use the dedicated JWT Decoder to inspect its segments and remember that decoding does not verify a signature.

Technical references: Base64URL alphabet and padding

Base64URL Encoder FAQs

Yes. Text is encoded to UTF-8 before Base64URL conversion. Use Base64URL Decoder on the complete output to restore those characters.
No. Those alphabet positions are only used when the encoded bytes require them. Many short messages look identical in standard Base64 and Base64URL.
No. It produces a reversible representation of the password. Encoding a secret does not make that secret confidential.