Base64 Encoder/Decoder
Encode text or files to Base64 and decode Base64 strings back to text.
Input
Output
How to use this tool
- Select 'Encode to Base64' or 'Decode from Base64'.
- Choose Text or File input when encoding.
- Enter your text or upload a file.
- View the converted output instantly.
- Copy or download the result.
About this tool
Base64 Encoder/Decoder is an online, free tool that converts text and files to/from Base64 format. No registration required! Base64 is widely used for embedding images in CSS, encoding data for URLs, and transmitting binary data as text. This tool handles both encoding and decoding with support for files and text.
Frequently asked questions
What is Base64 encoding used for?
Carrying binary data through channels that only handle text. That covers embedding an image directly in CSS or HTML with a data URI, attaching files to email via MIME, putting binary payloads inside JSON, and passing credentials in an HTTP Basic Authorization header.
Is Base64 a form of encryption?
No, and this is the single most important thing to know about it. Base64 is a reversible encoding with no key and no secret. Anyone can decode it instantly. It hides nothing. Use the Text Encryptor if you need actual confidentiality.
Why is my Base64 string longer than the original?
Because Base64 represents three bytes with four characters, so the output is always about 33 per cent larger than the input, plus padding. That overhead is the price of making binary data survive a text-only channel.
What do the equals signs at the end mean?
Padding. Base64 works in three-byte groups, and when the input does not divide evenly, one or two = characters are appended to fill the final group. Seeing one or two trailing equals signs is normal; three is not, and means the string is malformed.
Why does decoding my string fail?
Usually because it was passed through a URL and the + and / characters were altered, or because whitespace and line breaks were introduced when it was copied. URL-safe Base64 uses - and _ instead, and those variants need converting back before a standard decoder will accept them.
Can I encode a file rather than text?
Yes. Switch the input to File and choose one. The file is read in your browser and encoded there; it is never uploaded, so the tool is safe for documents you would not want on someone else's server.