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Encode & Decode Base64 Instantly (Text, URL-Safe & Standard)

Encode and decode Base64 strings with UTF-8 support. Supports standard Base64 and Base64URL. Perfect for encoding text, handling API tokens, embedding data URIs, and debugging web applications.

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How to Use Base64 Encoder/Decoder

How to Use the Base64 Encoder/Decoder:

  1. Select Mode: Choose Encode to convert plain text to Base64, or Decode to convert a Base64 string back to plain text. The mode label on the input area updates to reflect your selection.

  2. Choose Standard or Base64URL: Toggle the Base64URL switch to convert between standard Base64 (uses + and / characters) and URL-safe Base64URL (replaces + with - and / with _, removes = padding). Use Base64URL for JWT tokens, URL parameters, and filenames.

  3. Enter Input: Type or paste your text (for encoding) or your Base64 string (for decoding) into the input area. The tool handles emoji, international characters, and all Unicode text correctly using UTF-8.

  4. Click Convert: Click the Convert button to perform the encoding or decoding. The result appears in the output area immediately.

  5. Copy Output: Click Copy Output to copy the result to your clipboard. A confirmation toast appears when the copy succeeds.

  6. Swap: Use the Swap button to move the current output into the input field and switch modes — useful for round-trip testing (encode then decode to verify).

  7. Try a Sample: Click Sample to load an example input with UTF-8 characters including emoji. The conversion runs automatically so you can see what the output looks like.

  8. Clear: Click Clear to reset all fields and start fresh.

Common Use Cases:

  • API authentication: Encode Basic Auth credentials (username:password) for HTTP Authorization headers
  • Data URIs: Embed small images or files directly in HTML/CSS using Base64-encoded data
  • JWT inspection: Decode the header and payload segments of a JWT (each is Base64URL-encoded)
  • Email MIME content: Decode Base64-encoded email attachment content
  • Debugging: Decode Base64 tokens, cookies, or configuration values to inspect their content
  • URL-safe encoding: Use Base64URL mode for values passed in query strings or URL path segments

Tips and Best Practices:

  • Base64 is encoding, not encryption — anyone can decode it instantly; never use it for security
  • Base64 increases data size by approximately 33% (3 bytes → 4 characters)
  • Always remove whitespace and newlines from Base64 strings before decoding
  • Standard Base64 uses + and / which must be percent-encoded in URLs; use Base64URL instead
  • The = padding at the end of a Base64 string is optional in many contexts but required by strict decoders
  • For JWT tokens, the header and payload are Base64URL-encoded; the signature is also Base64URL but cannot be decoded to meaningful text without verifying it

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