Base64 Encoder / Decoder
Encode text to Base64 or decode Base64 strings — instantly, in your browser.
+ with -, / with _, and omits = padding. Used in JWT tokens and URLs where standard Base64 characters cause issues.
Text → Base64
Base64 → Text
What Is Base64?
Base64 is a binary-to-text encoding scheme that converts binary data into a string of
64 printable ASCII characters (A–Z, a–z, 0–9, +, /).
It is not encryption — it is purely an encoding format used to safely transmit binary data over
text-based channels that may not handle raw bytes correctly.
Base64 Encoding Online — Common Use Cases
JWT tokens use Base64url (URL-safe variant) to encode their header and payload sections. When you decode a JWT with this Base64 decoder online, you can read the claims directly. Everything happens locally in your browser, so you can safely Base64 decode online tokens and payloads without sending them to a server.
Data URIs embed images or files directly in HTML or CSS using
data:image/png;base64,..., eliminating an extra HTTP request.
A Base64 encoding online tool makes it easy to generate these URIs.
APIs and configuration files often Base64-encode binary payloads (certificates, icons, small files) so they can be stored as plain text in JSON or YAML.
Standard vs URL-safe Base64url
Standard Base64 converter output may contain +, /, and =
characters, which have special meaning in URLs and query strings.
Base64url replaces + → - and / → _,
and omits the = padding — making it safe for use in URLs, filenames, and JWT tokens
without percent-encoding.
Unicode and Emoji Support
This base64 encode online tool uses the TextEncoder API to first convert
your string to UTF-8 bytes before encoding. This ensures that multi-byte characters —
such as accented letters (é, ü, ñ), CJK characters (中文), and emoji (🚀) — are handled correctly,
matching how browsers and servers process text.