Base64 Encoder/Decoder
This Base64 tool converts text to Base64 and decodes Base64 strings back to readable text, handling UTF-8 characters such as accents and emoji correctly.
About this tool
This Base64 tool converts text to Base64 and decodes Base64 strings back to readable text, handling UTF-8 characters such as accents and emoji correctly.
How to use it
- Type or paste text or a Base64 string into the input box.
- Click Encode to convert text to Base64, or Decode to turn Base64 back into text.
- Click Copy Output to copy the result.
Good to know
- Base64 is defined in RFC 4648 and represents binary data using 64 ASCII characters: A–Z, a–z, 0–9, + and /, with = used for padding.
- Base64 output is about 33% larger than the input, because every 3 bytes become 4 characters.
- Text is encoded as UTF-8 before Base64 conversion, so non-English characters and emoji round-trip correctly.
- Base64 is an encoding, not encryption — anyone can decode it.
Runs entirely in your browser — nothing you enter is uploaded or stored.
Frequently asked questions
Is Base64 encryption?
No. Base64 is a reversible encoding for moving binary data through text-only channels. It provides no security, so never use it to hide passwords or secrets.
Why does decoding fail with 'Invalid Base64'?
The input contains characters outside the Base64 alphabet or has the wrong length. URL-safe Base64 uses - and _ instead of + and /, which standard decoding does not accept.
Where is Base64 used?
Common uses include email attachments (MIME), data: URLs for images, HTTP Basic authentication headers and the segments of JSON Web Tokens.
Is my data sent to a server?
No. Encoding and decoding run locally in your browser, so the text never leaves your device.