Base64 Encoder & Decoder — Free Online Tool
What is Base64?
Base64 is a binary-to-text encoding that converts binary data into a string of ASCII characters. It's commonly used to embed images in HTML/CSS, send binary data in JSON or XML, encode email attachments, and store binary content in text-based formats. Each Base64 character represents 6 bits of data, making the encoded output about 33% larger than the original.
How to use
- Choose Encode or Decode mode using the tabs above
- Type, paste, or upload a file in the input panel
- The tool converts in real-time as you type
- Copy the result or download it as a file
- Enable URL-safe mode to use
-and_instead of+and/
Frequently Asked Questions
Is Base64 encoding the same as encryption?
No. Base64 is an encoding scheme, not encryption. It converts binary data to ASCII characters for safe transport in text-based formats. Anyone can decode it without a key. Never use Base64 to hide sensitive data.
Can I encode any file type to Base64?
Yes. Any file — images, PDFs, audio, binaries — can be Base64-encoded. The output is always a plain ASCII string. Use the File mode tab to upload files directly.
What is URL-safe Base64?
Standard Base64 uses '+' and '/' which must be percent-encoded in URLs. URL-safe Base64 replaces '+' with '-' and '/' with '_', making the output safe to use directly in URLs and filenames without percent-encoding.
Why is Base64 output larger than the original?
Base64 encodes 3 bytes into 4 characters, so output is approximately 33% larger than the original binary. This is expected and unavoidable with Base64.
Does this tool send my data to a server?
No. All encoding and decoding runs entirely in your browser. Your data never leaves your device.