MultiConvers

Base64 Encoder & Decoder

Encode plain text to Base64 or decode Base64 back to text. Unicode, Swedish characters and emoji are handled as UTF-8.

How to use

  1. Paste the text you want to encode, or the Base64 you want to decode.
  2. Choose Encode or Decode.
  3. Copy the result. Invalid Base64 shows an error instead of a garbled string.

How it works

Base64 turns binary data into ASCII using 64 characters (A–Z, a–z, 0–9, + and /) plus = padding. It is encoding, not encryption: anyone can decode the result.

Browsers expose btoa and atob, but those work on binary strings, not JavaScript UTF-16 text. This page first encodes your text as UTF-8 bytes with TextEncoder, then Base64-encodes those bytes. Decoding reverses the steps.

Invalid Base64 is rejected with an error instead of a corrupted string. Nothing is uploaded.

Formula

encode: UTF-8 bytes → Base64
decode: Base64 → UTF-8 bytes → text
Alphabet = A–Z a–z 0–9 + / with = padding

Worked examples

  • ASCII

    Hello → SGVsbG8=

  • Swedish and emoji

    Göteborg 👋 → R8O2dGVib3JnIPCfpYg=

Useful notes

  • Whitespace in Base64 input is ignored.
  • This is encoding, not encryption. Anyone can decode the result. Do not use it to hide secrets.
  • The text stays in your browser and is not sent to analytics.

FAQ

Is Base64 encryption?

No. It is a reversible encoding. Anyone who sees the Base64 can decode it. Do not use it to hide secrets.

Read more: What is Base64?

How do I encode text as Base64?

Paste the text and choose Encode. The page converts to UTF-8 first, so å, ä, ö and emoji survive.

Read more: How to encode Base64

How do I decode Base64?

Paste the Base64 and choose Decode. Invalid input shows an error instead of a half-decoded string.

Read more: How to decode Base64

Does this handle Unicode?

Yes. Text is converted through UTF-8, so å, ä, ö and emoji survive a round trip.

Is my text uploaded?

No. Encoding and decoding run in your browser and are not sent to analytics.

Guides

Related tools

See all Utilities tools.