Choose operation and profile
Alphabet and padding never change silently.
Choose · validate · convert
Base64Lens converts UTF-8 text with explicit standard or URL-safe alphabets, explicit padding and visible byte evidence. Input stays in the browser.
No account, upload, files, JWT parsing, charset guessing, saved data or public result link.
Three explicit steps
Alphabet and padding never change silently.
One invalid character clears stale output.
Byte evidence defines the delivered artifact.
Small local encoding jobs
Explicit profile · local text
Choose encode or decode, standard Base64 or base64url, and padded or unpadded form. The complete text is validated in this browser without upload, automatic repair or hidden variant detection.