What is Base64 Encoding?
Base64 encoding converts binary data into ASCII text format using 64 printable characters. This base64 encoder online tool lets you encode text strings into Base64 format or decode Base64 strings back to readable text — entirely in your browser with no server uploads.
Base64 is commonly used when you need to transmit binary data over systems designed for text, like embedding images in HTML/CSS or sending data in JSON APIs. The encoding process takes every 3 bytes of input and represents them as 4 ASCII characters from a set of 64 safe characters (A-Z, a-z, 0-9, +, /).
How to Use the Base64 Encoder/Decoder
- Encode: Paste your text into the input field and click “Encode to Base64”
- Decode: Paste a Base64 string and click “Decode from Base64”
- URL-safe mode: Toggle this option to use URL-safe Base64 (replaces
+with-and/with_) - Copy: Click the copy button to copy the result to your clipboard
The tool validates your input and displays error messages if the Base64 string is malformed.
When to Use Base64 Encoding
- Embedding images directly in CSS or HTML (
data:URIs) - Transmitting binary data in JSON payloads
- Encoding authentication credentials in HTTP headers
- Storing binary data in text-based configuration files
- URL-safe encoding for passing data in query parameters
FAQ
Is Base64 encoding secure?
No. Base64 is an encoding format, not encryption. Anyone can decode Base64 strings instantly. Never use this base64 encoder online for sensitive data that requires security — use proper encryption instead.
What’s the difference between standard and URL-safe Base64?
Standard Base64 uses + and / characters which have special meaning in URLs. URL-safe Base64 replaces them with - and _ to safely pass encoded data in URLs without escaping.
Why does Base64 make data larger?
Base64 increases data size by approximately 33% because it represents 3 bytes of input with 4 bytes of output. This trade-off allows binary data to be safely transmitted as text.
Need to work with other encoding formats? Try our URL Encoder/Decoder for percent-encoding or Hash Generator for one-way hashing.