Base64 Encoder/Decoder

Encode and decode Base64 strings instantly. Base64 is a binary-to-text encoding scheme that represents binary data as a sequence of ASCII characters, making it safe for transmission over text-based protocols. This tool is essential for developers working with data URLs, HTTP basic authentication headers, email MIME attachments, and embedding images directly in HTML or CSS. All encoding and decoding happens locally in your browser — no data is ever sent to a server.

Input

Output

Common Uses

Data URLsdata:text/plain;base64,

HTTP AuthAuthorization: Basic [base64]

EmailMIME encoding

EmbeddingImages in HTML/CSS

About Base64 Encoding

Base64 encoding converts binary data into a safe ASCII string format using 64 printable characters. It is widely used when you need to transfer data that may be corrupted by text-based systems, such as email bodies or URL parameters. While Base64 is not encryption and should not be used for security, it is invaluable for data serialization and embedding.

Frequently Asked Questions

Is Base64 secure?No. Base64 is an encoding, not encryption. Anyone can decode it. Use it for data transport, not for protecting sensitive information.

Why does Base64 make data longer?Base64 encodes every 3 bytes into 4 characters, increasing data size by roughly 33%. This overhead is the trade-off for safe text-based transmission.

Where is Base64 commonly used?Base64 is used in data URLs, HTTP Basic Auth headers, email attachments, JWT tokens, and embedding images directly in HTML or CSS files.