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Base64 Encoder / Decoder

Encode text or file data into Base64 for safe transport in URLs, JSON, or HTML, and decode it back to the original. Unicode is handled correctly through UTF-8, so accents and emoji round-trip without corruption.

Output

How it works

The tool uses the browser's native TextEncoder and btoa / atob with a UTF-8 shim, which means Unicode input survives the trip. File mode reads a file with FileReader and returns a data URI you can paste directly into HTML or CSS.

Common ways people use it

  • Embedding a small icon directly in CSS as a data URI
  • Storing a binary payload inside a JSON field
  • Decoding a Base64 blob from a webhook to inspect it
  • Inlining an SVG in HTML without a separate file

Frequently asked questions

Is Base64 a form of encryption?+
No. Base64 is a reversible encoding designed to make binary data safe in text-only contexts. Anyone can decode it without a key, so never rely on it to hide secrets.
Why is the encoded output longer than the input?+
Base64 represents every three bytes of input as four characters of output, so encoded data is about 33 percent larger. That is the cost of using only printable characters.
Why do emojis sometimes decode as garbled characters?+
Plain btoa only accepts Latin-1 bytes. This tool encodes your text as UTF-8 first, so multi-byte characters survive encoding and decoding intact.

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