Base64 converts binary data into ASCII text so it can travel through systems that expect text. It is an encoding format, not encryption, so anyone who receives the encoded value can decode it.
Base64 versus Base64URL
Standard Base64 uses plus and slash characters and may include padding. Base64URL replaces characters that are awkward in URLs and commonly omits padding. Use the variant expected by the receiving API or token format.
Text and image workflows
For text, choose UTF-8 before encoding so characters outside basic ASCII round-trip correctly. For images, a Data URL combines the media type with the Base64 payload and can be embedded directly in HTML or CSS.
Do not treat Base64 as a secret
Base64 does not protect passwords, API keys, or private information. Use encryption or a proper secret-management system when confidentiality is required.