Base64 Encoder & Decoder
Encode text to Base64 or decode Base64 back to text instantly. Supports UTF-8, URL-safe encoding, file uploads, and data URI generation.
About Base64 Encoding
Base64 encoding converts binary data into a set of 64 printable ASCII characters. Every 3 bytes of input become 4 characters of output, making the encoded result roughly 33% larger than the original. The character set uses A-Z, a-z, 0-9, plus (+), and slash (/), with equals (=) for padding.
Common Use Cases
Base64 is used in email attachments (MIME), embedding images in HTML/CSS via data URIs, storing binary data in JSON or XML, HTTP Basic Authentication headers, and encoding cryptographic keys and certificates (PEM format).
Limitations
Base64 increases data size by ~33%, so it's not ideal for large files. It provides no security — it's encoding, not encryption. For URL parameters, use URL-safe Base64 (replacing + with - and / with _) to avoid encoding issues.