Why base64 to utf8 string?
Base64 to UTF-8 string is one of the most common tasks developers hit when working with APIs, files, email attachments, and data URIs.
More Base64 guides on base64app — with copy-paste code and a free browser tool you can use without installing anything.
Quick reference
Base64 maps every 3 bytes to 4 ASCII characters. Padding with = may appear at the end. URL-safe variants swap +/ for -_.
When in doubt, paste your string into the tool below — base64app auto-repairs whitespace, data: prefixes, and padding issues.
Copy-paste code
JavaScript (browser)
// Decode base64 to UTF-8 text
const text = atob('SGVsbG8sIGJhc2U2NGFwcCE=');
console.log(text);
// Decode to Uint8Array (binary-safe)
const binary = atob('SGVsbG8sIGJhc2U2NGFwcCE=');
const bytes = Uint8Array.from(binary, (c) => c.charCodeAt(0));Python 3
import base64
text = base64.b64decode('SGVsbG8sIGJhc2U2NGFwcCE=').decode('utf-8')
print(text)
# Raw bytes
data = base64.b64decode('SGVsbG8sIGJhc2U2NGFwcCE=')