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Base64 Encoder / Decoder

Encode and decode Base64, with full Unicode and URL-safe support.

About this tool

Base64 represents binary data using 64 printable ASCII characters. It is how binary content travels through channels that only handle text — JSON payloads, data URIs, email attachments and the header and payload of a JSON Web Token.

Base64 is an encoding, not encryption. Anyone can decode it, so it protects nothing on its own.

How to use it

  1. Pick a direction: text to Base64, or Base64 back to text.
  2. Paste your input. The result updates as you type.
  3. Enable URL-safe output if the value goes into a URL or a JWT.
  4. Copy or download the result.

Example

Text
Hello, world!
Base64
SGVsbG8sIHdvcmxkIQ==

FAQ

Is my data uploaded anywhere?
No. Encoding and decoding happen in your browser using its built-in APIs. Nothing is sent to a server, and this page has no analytics.
Does it handle Arabic, emoji and other Unicode?
Yes. Text is converted to UTF-8 bytes before encoding, and decoded bytes are read back as UTF-8, so multi-byte characters and emoji round-trip exactly.
What is URL-safe Base64?
A variant that replaces + with - and / with _, and drops the = padding, so the value is safe inside a URL. JSON Web Tokens use it. This tool decodes both variants automatically.
Why does decoding sometimes fail?
Either the input contains characters outside the Base64 alphabet, its length is impossible, or the decoded bytes are not valid UTF-8 text — for example because the original data was an image rather than text.
Is Base64 encryption?
No. It is a reversible encoding with no key. Never use it to protect secrets.