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Encoding

Base64 Decoder

Quickly convert Base64 encoded strings back into clean UTF-8 text. Automatically detects URL-safe Base64 variants and flags invalid characters.

Your input is processed locally in your browser and is not sent to our server.
Base64 Encoded Input32 chars
Decoded Plain Text

Key Features

  • Automatic padding detection (= and ==)
  • Supports both standard and URL-safe Base64 inputs
  • Safe UTF-8 decoder with error isolation
  • One-click copy for decoded text
  • Character length breakdown
  • 100% in-browser processing

How to Use Base64 Decoder

  1. 1Paste your Base64 encoded string into the input area.
  2. 2Click 'Decode Base64'.
  3. 3Read the decoded string or inspect invalid character warnings.
  4. 4Copy the result with one click.

Frequently Asked Questions

Why do I see 'Invalid Base64 string'?

Base64 strings must only contain A-Z, a-z, 0-9, +, /, and padding '=' (or '-' and '_' for URL-safe). Any whitespace or illegal characters trigger validation errors.