Utilix knowledge base
What is Base64 Encoding?
Published Apr 17, 2026
What is Base64?
Base64 is an encoding scheme that converts binary data into a set of 64 printable ASCII characters (A–Z, a–z, 0–9, +, /). It was designed to safely transport binary data through systems that only handle text — like email, JSON, or URLs.
Why 64?
64 characters fit neatly into 6 bits each, and 3 bytes of binary data encode cleanly into 4 Base64 characters. The = padding character ensures the output length is always a multiple of 4.
Common uses
- Embedding images in CSS or HTML (
data:image/png;base64,...) - Encoding credentials in HTTP Basic Auth headers
- Passing binary data in JSON API responses
- Email attachments (MIME encoding)
Is Base64 encryption?
No. Base64 is encoding, not encryption. Anyone can decode it instantly. Never use Base64 as a security measure — use proper encryption like AES or TLS for sensitive data.
UTF-8 and Base64
Standard Base64 works on bytes, not characters. For non-ASCII text (emojis, accents), you need to convert to UTF-8 bytes first. The Base64 tool on this site handles this automatically.
Try it
Use the Base64 Encode / Decode tool to encode any text to Base64 or decode Base64 back to plain text in your browser.