Base64 Encoder and Decoder Online
Description
Encode binary data or text to Base64 for email attachments and APIs, or decode it back effortlessly with built-in validation.
About Base64 Encoder and Decoder Online
The Base64 Encoder / Decoder converts text and binary data to and from Base64 directly in your browser. Base64 represents binary data as ASCII text, which makes it safe to embed in URLs, JSON, XML, email attachments, and data URIs. Encode or decode instantly with built-in validation — nothing is sent to a server.
How to use
- Choose whether your source is plain text or a file.
- To encode, type or paste text (or upload a file) into the input — the Base64 output appears immediately.
- To decode, paste a Base64 string; the decoded text is shown and validated.
- Copy the result, or download it when working with files.
Examples
| Example | Input | Output |
|---|---|---|
| Encode | Hello, World! | SGVsbG8sIFdvcmxkIQ== |
| Decode | Zm9vYmFy | foobar |
Frequently asked questions
Is Base64 encryption?
No. Base64 is an encoding, not encryption. Anyone can decode it — it provides no security or confidentiality. Use it for safe transport of binary data, not to protect secrets.
Why is Base64 output longer than the input?
Base64 represents every 3 bytes of input as 4 ASCII characters, so the output is roughly 33% larger than the original data. That overhead is the trade-off for text-safe transport.
What is a data URI?
A data URI embeds a file directly in a URL using Base64, e.g. data:image/png;base64,iVBORw0K… It lets you inline small images or fonts without a separate HTTP request.
Does decoding happen on a server?
No. Encoding and decoding run entirely in your browser, so even sensitive data stays on your device.