Base64 Encoder & Decoder

Encode text and images to Base64, or decode a Base64 string back to its original form.

Input
Result
The Base64 string will appear here.

Text runs through a Koaris edge function; images are read and encoded entirely in your browser.

Free · Private · Runs in your browser

How to use

  1. Paste text, or click Import image to load a file.
  2. Click Encode to get the Base64 string, or Decode to reverse one.
  3. Copy the result or download it as a text file.

What Base64 is

Base64 converts binary data into a text-only format using 64 ASCII characters, so it survives transport through systems that expect text — email, URLs, JSON APIs — without being altered.

Why it exists

Many protocols only handle text safely. Base64 lets you embed an image, a file, or arbitrary bytes inside HTML, CSS, or a URL without special characters breaking things.

How it works

  • The input is read as raw bytes.
  • Bytes are grouped 3 at a time (24 bits) and split into four 6-bit groups.
  • Each 6-bit group maps to one character: A–Z, a–z, 0–9, +, /.
  • When the input isn't a multiple of 3 bytes, = padding is added so the length stays valid.

Examples

  • Hello, World!SGVsbG8sIFdvcmxkIQ==
  • OpenAIT3BlbkFJ

Questions

Can I encode an image?
Yes. Use “Import image” — the file is read and encoded in your browser, and you get a data URL plus ready-to-paste IMG and CSS snippets.
Is Base64 encryption?
No. It is fully reversible with no key. Anyone can decode it — use it for transport, not for secrecy.
Why does the output end in = or ==?
That is padding, added when the input length is not a multiple of 3 bytes. It keeps the encoded length valid.

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