About this tool
The Base64 Encoder / Decoder is a free online tool that converts text to Base64 and back instantly, right in your browser. Base64 is a way of encoding binary data as ASCII text so it can be safely transmitted over channels that only support text: email, URLs, JSON strings, HTML attributes, and many API payloads.
How it works
1
Paste your text or Base64
Type or paste plain text to encode, or paste an existing Base64 string to decode.
2
Click Encode or Decode
Encode converts your text to Base64. Decode reverses it. Errors are reported if the input is not valid Base64.
3
Copy the result
The result is shown in a code block. Copy it with one click.
Frequently Asked Questions
Is Base64 encryption? v
No. Base64 is encoding, not encryption. Anyone can decode it instantly. It provides zero security.
Why is Base64 output 33% larger than the input? v
Base64 encodes every 3 input bytes as 4 output characters. This is the cost of making binary data text-safe.
Is my data sent to a server? v
No. Encoding and decoding happen entirely in your browser using btoa() and atob().
What characters are in the Base64 alphabet? v
A-Z, a-z, 0-9, plus '+' and '/'. '=' is used as padding. A URL-safe variant replaces '+' with '-' and '/' with '_'.
Does it work with emoji and non-ASCII text? v
Yes. The tool handles full Unicode using UTF-8 encoding.
Is this free? Any limits? v
Completely free. No signup, no limits on size.