Base64 Encoder & Decoder

How to use the Base64

1. Pick Encode or Decode at the top.
2. Type or paste text into the Input box, or click Encode a file to turn an image or document into a Base64 data URI.
3. Toggle URL-safe and No padding if you need base64url output (for JWTs, URLs or filenames).
4. When decoding an image data URI, a preview appears automatically. Click Copy to grab the result.

Privacy: this tool runs entirely in your browser. Your input is never sent to, received by, or stored on any server — there are no uploads and no tracking of what you enter.

About Base64

What is Base64?

Base64 is a binary-to-text encoding scheme that represents binary data using 64 printable ASCII characters (A–Z, a–z, 0–9, + and /). It is widely used to embed images in CSS/HTML (data URIs), send binary attachments over text-only protocols like email (MIME), and store small blobs in JSON or XML.

How Base64 encoding works

Input bytes are grouped into 24-bit chunks (3 bytes), then split into four 6-bit values. Each 6-bit value maps to one Base64 character. When the input length isn't divisible by 3, one or two = padding characters are added so the output length is always a multiple of four.

When to use it

Use Base64 when you need to move or store binary data through a text channel. Note that it is encoding, not encryption — it provides no security and is trivially reversible, as this tool demonstrates.

Frequently asked questions

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