Base64 Encoding Explained (With a Free Online Encoder/Decoder)
What Base64 is, when to use it, when not to, and how to encode or decode any text in your browser with a free Base64 tool.
Base64 is one of the most misunderstood encodings on the web. It is not encryption, it is not compression, and it makes data about 33% bigger. But it is the standard way to safely move binary data through systems that only understand text.
What Base64 actually does
Base64 takes bytes and rewrites them using only 64 safe characters: A–Z, a–z, 0–9, plus + and /. The result is text that survives transport through email, JSON, URLs (with the URL-safe variant), and HTTP headers without corruption.
When to use Base64
- Embedding small images directly in CSS or HTML (data: URIs)
- HTTP Basic Auth headers
- Encoding JWT segments
- Sending binary attachments through JSON APIs
When not to use it
Never use Base64 as a security measure — anyone can decode it instantly in our Base64 Encoder / Decoder tool. For passwords or secrets, use a proper encryption library or a one-way hash.
Related encodings
If your data is going into a URL query string, use URL Encoder / Decoder instead. For text being injected into HTML, use HTML Encoder / Decoder to escape angle brackets, ampersands, and quotes safely.