Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 back to plain text. Works in your browser, no data sent to servers.
What is Base64?
Base64 is a binary-to-text encoding scheme that represents binary data in an ASCII string format. It's commonly used for encoding data in URLs, emails, and data URIs.
Common Use Cases
- • Encoding images for data URIs (CSS/HTML)
- • Basic HTTP authentication headers
- • Embedding binary data in JSON or XML
- • Email attachment encoding (MIME)
How to Encode and Decode Base64 Online
- 1. Select Encode to convert plain text to Base64, or Decode to reverse Base64 back to text.
- 2. Paste or type your input — results update automatically.
- 3. Click Swap Input/Output to flip the result back for chained operations.
- 4. Click Copy to copy the output to your clipboard.
Frequently Asked Questions
What is Base64 encoding used for?
Base64 is used to safely transmit binary data through text-based channels like HTTP headers, HTML data URIs, JSON fields, and email MIME attachments. It converts binary bytes into printable ASCII characters.
Does Base64 encoding compress data?
No — Base64 increases data size by approximately 33%. It is an encoding scheme, not a compression algorithm. Use gzip or brotli for compression.
What is the difference between Base64 and Base64URL?
Standard Base64 uses + and / characters which are unsafe in URLs. Base64URL replaces + with - and / with _, making it safe for URL parameters. JWTs use Base64URL encoding.
Is my data sent to a server?
No. All encoding and decoding runs entirely in your browser. Your text is never uploaded or stored anywhere.