Base64 Encoder/Decoder

About Base64 encoding

Base64 is a way of representing arbitrary binary or text data using only 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It's used everywhere data needs to safely travel through text-only channels — embedding images in CSS/HTML, encoding attachments in emails, storing binary data in JSON, or passing data in URLs and API tokens — because many of those channels can't reliably handle raw binary bytes.

How the conversion works

Encoding takes your text's raw UTF-8 bytes and groups them into 3-byte chunks, converting each chunk into 4 Base64 characters (padding with "=" at the end if the input length isn't a multiple of 3). Decoding reverses this exactly, converting the Base64 characters back into bytes and then interpreting those bytes as UTF-8 text. Because of this 3-to-4 byte expansion, encoded output is always about 33% longer than the original.

Frequently asked questions

Is Base64 the same as encryption?

No. Base64 is just a reversible text representation, not encryption — anyone can decode it back to the original data instantly with no key or password required. Never use it to protect sensitive information.

Why did decoding fail with an error?

This usually means the text isn't valid Base64 — it may contain characters outside the Base64 alphabet, have incorrect padding, or (once decoded) not form valid UTF-8 text, which this tool reports rather than showing garbled output.

Does this tool send my text anywhere?

No. Encoding and decoding happen entirely in your browser using built-in JavaScript functions — nothing you type is uploaded, making it safe for sensitive text and tokens.