Base64 Encoder & Decoder
What Is Base64 Encoding?
Base64 is a binary-to-text encoding scheme that represents binary data as an ASCII string. It's commonly used to embed images in HTML/CSS, transmit data in URLs, encode email attachments (MIME), and store complex data in JSON or XML.
How to Use This Tool
Select Encode or Decode mode using the tabs above. Paste your text or Base64 string into the input field. With "Live update" enabled, the output updates automatically as you type. You can also click the action button to process manually.
Features
- Encode & Decode — Switch between modes with one click
- URL-safe mode — Uses - and _ instead of + and / for URL compatibility
- Live updates — See results as you type
- Unicode support — Handles UTF-8 text correctly
- 100% client-side — Your data stays in your browser
Frequently Asked Questions
Why does Base64 make data larger?
Base64 encoding increases data size by approximately 33% because it represents 3 bytes of binary data as 4 ASCII characters. This trade-off is acceptable when you need to transmit binary data through text-only channels.
What is URL-safe Base64?
Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 replaces them with - and _ to avoid encoding issues in URLs and filenames.