Base64 Decoder and Encoder

Decode Base64 to text and encode text to Base64, with full UTF-8 support.

What it decodes

Standard and URL-safe Base64: +/ and -_ are both recognized automatically.
Missing padding: input without trailing =, as used in JWTs and URLs.
Line breaks and spaces: wrapped Base64 from emails, PEM files or logs.
Data URLs: paste data:application/json;base64,... as is.

UTF-8 that works

The browser's btoa and atob only handle Latin-1, so text like çağ or emoji breaks or comes back garbled. Shapecheck encodes and decodes UTF-8 properly, and tells you when decoded bytes are not valid UTF-8 text.

JSON and binary data

When the decoded text is JSON, such as a Kubernetes secret, an API payload or one part of a JWT, it is formatted for you. Binary data is shown as a hex dump instead of unreadable characters.

Errors

Invalid characters, misplaced padding and incomplete data are reported with line and column and highlighted in the editor.

Privacy

Everything runs in your browser. What you paste is never uploaded to a server. It is kept only in this browser's local storage, so it is still there after a reload; Clear removes it.