Base64 Encoder & Decoder

Encode and decode Base64 strings, including UTF-8 and binary.

Encode any text or file to Base64 and decode Base64 back to text. Handles full Unicode (UTF-8) correctly and supports URL-safe Base64 used in JWTs.

Common use cases

  • Encode binary files for embedding in HTML, CSS, JSON or email MIME parts
  • Decode JWT segments to inspect headers and payloads
  • Encode credentials for HTTP Basic auth (Authorization: Basic ...)
  • Convert API request/response samples between binary and text representations

Frequently asked questions

What is URL-safe Base64?
A variant that replaces + and / with - and _ so the output is safe to embed in URLs and JWTs without further encoding.
Why do I get garbled text after decoding?
If the source was UTF-8 but you decoded as ASCII, multi-byte characters break. Toggle to UTF-8 decoding and it should render correctly.
Can I encode files?
Yes — drop a file in and the encoder produces a data URI suitable for inline embedding (data:image/png;base64,…).

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