Base64 Encoder / Decoder
Encode and decode Base64 strings instantly.
Instant Encoding
Convert plain text to Base64 format instantly for use in data URLs, APIs, or email attachments.
Quick Decoding
Decode Base64 strings back to readable text with a single click. Perfect for inspecting encoded payloads.
Privacy Guaranteed
All conversion happens in your browser. Your data never leaves your device or gets uploaded to any server.
Error Detection
Invalid Base64 strings are detected automatically with clear error messages to help you fix encoding issues.
Understanding Base64 Encoding
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's widely used to transmit data over media designed to handle text, such as email attachments, data URLs in HTML/CSS, and API authentication tokens. Base64 ensures that binary data remains intact across systems that might otherwise corrupt it.
When to Use Base64
Base64 encoding is essential for embedding images directly in HTML (data:image/png;base64,...), transmitting files via JSON APIs, encoding authentication credentials for HTTP Basic Auth, and safely including binary data in XML or JSON. It's also commonly used in JWT tokens and OAuth flows. While Base64 increases data size by approximately 33%, it's the standard solution for text-safe binary transmission.
How Base64 Encoding Works
Base64 converts binary data into groups of 6 bits, then maps each group to one of 64 ASCII characters (A-Za-z0-9+/). Every 3 bytes of input data produces 4 bytes of Base64 output. Padding characters (=) are added to ensure the output length is a multiple of 4. This process is completely reversible—decoding simply reverses the character mapping and removes padding to restore the original binary data.
Base64 FAQ
Base64 is a method of encoding binary data into ASCII text format using 64 printable characters. It allows binary files to be transmitted through protocols that only support text, such as email or JSON APIs.
No! Base64 is encoding, not encryption. Anyone can decode Base64 strings—there's no password or key required. It's designed for data transmission compatibility, not security. Never rely on Base64 for protecting sensitive information.
Use Base64 when you need to embed binary data (like images) in text formats, transmit files through JSON/XML APIs, encode credentials for HTTP Basic Auth, or create data URLs for inline images in HTML/CSS.
The = characters are padding to ensure the Base64 output length is a multiple of 4. They indicate that the original data length wasn't divisible by 3. Padding is required for proper decoding and is part of the Base64 standard.
Yes—our tool processes everything client-side in your browser. Your data never leaves your device, is never uploaded to our servers, and is never stored. However, remember that Base64 is NOT encryption and can be decoded by anyone.
This tool is designed for text strings. For file encoding, you'd need to first read the file as binary data (using JavaScript FileReader or similar), then encode that binary data. Many specialized tools exist specifically for encoding files to Base64.