Base64 Decoder
Decode Base64 encoded text back to readable format instantly
Convert Base64 encoded data back to its original text format with advanced error handling and encoding detection support.
Drag Base64 file here or click to select
Character encoding for the decoded text output
Handle URL-safe Base64 format (uses - and _ instead of + and /)
Require valid Base64 format and fail on invalid input
Keep line breaks in the Base64 input string
Line ending format for decoded text output
Helpful Tips
• Standard Base64 uses A-Z, a-z, 0-9, +, / and = for padding
• URL-safe Base64 replaces + with - and / with _ to work in URLs
• Invalid Base64 will show an error in strict mode
• Missing padding is automatically added in non-strict mode
Decoded text will appear here
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How Base64 Decoding Works
Convert Base64 encoded data back to original text format
Input Base64
Paste or upload your Base64 encoded text or file
Configure Settings
Choose decoding options and format settings
Decode Text
Our decoder processes your text instantly in your browser
Get Result
Copy or download your decoded text instantly
Key Features
Comprehensive Base64 decoding capabilities
Format Detection
Automatically detects and handles both standard and URL-safe Base64 formats
Error Handling
Comprehensive error detection with helpful messages for invalid input
Character Encoding
Support for multiple output encodings including UTF-8, UTF-16, ASCII, and Latin-1
Strict & Flexible Modes
Choose between strict validation or automatic correction for imperfect input
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Frequently Asked Questions
What is Base64 decoding?
Base64 decoding is the process of converting Base64 encoded data back to its original binary format. Base64 is an encoding scheme that represents binary data in an ASCII string format by translating it into a radix-64 representation.
What's the difference between standard and URL-safe Base64?
Standard Base64 uses '+' and '/' characters, which have special meanings in URLs. URL-safe Base64 replaces these with '-' and '_' respectively, making it safe to use in URLs and filenames without additional encoding.
Why is padding needed in Base64?
Base64 padding uses '=' characters to ensure the encoded string length is a multiple of 4. This padding is necessary for proper decoding when the original data length isn't a multiple of 3 bytes.
Can Base64 contain invalid characters?
Yes, if the encoding process was corrupted or if the data was mixed with other characters. Our strict mode will reject invalid input, while flexible mode attempts to correct common issues like missing padding.
Is Base64 decoding secure?
Yes, Base64 decoding is completely secure. It's simply a reversible encoding process, not encryption. All decoding happens in your browser, so your data never leaves your device.