ShethHub

Base64 Encoder & Decoder

Encode text to Base64 or decode Base64 back to text, entirely in your browser. Supports multi-byte UTF-8 text and the URL-safe alphabet (RFC 4648 §5). Your input is never uploaded to a server.

Runs locally in your browser
Mode

How to use Base64 Encoder & Decoder

  1. Choose a mode. Select Encode to convert text to Base64, or Decode to convert Base64 back to text.
  2. Enter input. Type or paste your text or Base64 string into the input panel.
  3. Convert and export. Click Encode/Decode, then copy or download the result.

Example

Encoding a short greeting.

Text

Hello, world!

Options: Encode, URL-safe off

Base64

SGVsbG8sIHdvcmxkIQ==

With URL-safe on, the trailing == padding is left out.

Formats, limits and privacy

Input
Plain text
Output
Plain text
Limits
  • Encodes and decodes text, using UTF-8.
  • Binary files and images are not supported; decoded bytes must be valid UTF-8 text.
  • No fixed size limit; very large inputs depend on your device's memory.
Privacy
Everything happens in your browser. Your input is never uploaded to a server.

Troubleshooting

Decoding fails with an invalid character

The input contains characters outside the Base64 alphabet. If it has - or _, tick URL-safe. Remove any spaces or line breaks inside the text, such as those added by email wrapping.

The decoded text is garbled

The data was probably binary (an image or a compressed file) or used a text encoding other than UTF-8.

My output differs from another tool by an = at the end

Padding is optional in some systems. URL-safe Base64 here never adds it; standard Base64 always does.

Frequently asked questions

Is my text uploaded anywhere?

No. Encoding and decoding run entirely in your browser.

What is "URL-safe" Base64?

Standard Base64 uses + and / and may end in = padding, which can conflict with URLs and filenames. URL-safe Base64 (RFC 4648 §5) replaces + with -, / with _, and omits padding.

Does this handle emoji and non-English text?

Yes. Text is encoded as UTF-8 before Base64 conversion, so multi-byte characters round-trip correctly.