Base64 Decoder
Decode Base64 back to plain text.
Open Base64 Decoder
Base64 Encoder
Encode plain text to Base64 instantly.
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Frequently asked questions
Common questions about this tool.
Base64 is a binary-to-text encoding that maps 3 bytes to 4 printable ASCII characters from a 64-character alphabet, plus padding. It lets binary data travel through text-only channels.
Encoding represents information in a specific representation ruleset—e.g., UTF-8 for text, Base64 for binary-in-text, or percent-encoding in URLs. It is reversible with the right decoder.
Protocols and formats that only allow safe ASCII text still need to carry binary attachments, images, and keys. Base64 wraps bytes so they survive JSON, XML, and SMTP text bodies.
No. Base64 is an encoding, not encryption. Anyone can decode it. Do not rely on Base64 alone to protect secrets.
Base64 strings are padded with '=' so the length is a multiple of four. Decoders accept standard padding automatically.
This tool is oriented at text input. For arbitrary binary, use a workflow that reads files as bytes in an environment that supports it.
Base64URL replaces +/ with -_ and often omits padding for use in URLs and JWTs. Standard Base64 uses +/ and padding; choose the variant your consumer expects.
No. It expands size by roughly 4/3. The tradeoff is safe transport and embedding in text formats, not compression.
Data URLs for small images, embedding files in JSON, email MIME parts, certificate PEM blocks, and attaching small blobs in logs or configs.
A character set defines symbols; an encoding maps those symbols to bytes (e.g., Unicode + UTF-8). Base64 sits on top: it encodes raw bytes as visible characters.