Base64 Encoder/Decoder
A high-performance utility for encoding and decoding strings using the Base64 scheme. Ideal for binary-to-text transfers and secure URL data handling.
Input
Decoded Output
Privacy First
All processing happens locally in your browser. Your data is never sent to our servers.
Instant Processing
Handle large strings of data instantly with our optimized encoding engine.
URL Optimized
Toggle URL-safe mode to ensure your Base64 strings are ready for query parameters.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 encoding is commonly used to transfer binary data (like images or documents) over text-based protocols such as HTTP and SMTP. It converts non-text data into a reliable, ASCII-safe string format that won't be corrupted by systems that process only text.
Is Base64 a form of encryption?
No. Base64 is an encoding scheme, not encryption. It does not use a key, and anyone can easily decode a Base64 string back into its original format. Do not use Base64 to secure sensitive information like passwords or personal data.
What does "URL Safe" mean?
Standard Base64 outputs can include "+" and "/" characters, which conflict with how URLs are parsed in browsers. "URL Safe" Base64 substitutes "+" with "-" and "/" with "_", allowing you to safely pass encoded strings strictly as URL query parameters.
Why does my Base64 string end with "="?
The "=" character acts as a padding byte. Base64 encodes data in blocks of three bytes. If the original data is not perfectly divisible by three, padding is appended to the end of the string to inform the decoder so it reconstructs the file correctly.
How much does Base64 increase file size?
Base64 encoding increases the physical size of the data by roughly 33%. This is because every 3 bytes of raw binary data gets converted into 4 characters of ASCII text.
Why use Base64 instead of Hex?
Base64 is much more space-efficient. Hex (Base16) uses 2 ASCII characters to represent a single byte resulting in a 100% overhead, whereas Base64 uses 4 characters per 3 bytes resulting in only a 33% overhead.
Can Base64 encode Unicode or UTF-8 characters?
Yes, but the string must first be safely converted into an array of UTF-8 encoded bytes before being converted to Base64. Our tool handles these conversions automatically behind the scenes via modern TextEncoder APIs.
Is Base64 decoding case-sensitive?
Absolutely. Base64 relies on an exact mapping of 64 specific characters (A-Z, a-z, 0-9, +, /). Changing the casing of the string will fundamentally change the decoded binary data.