Base64 Encoder
Encode plain text to Base64 instantly.
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Base64 Decoder
Decode Base64 back to plain text.
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Frequently asked questions
Common questions about this tool.
Decoding reverses encoding: Base64 text becomes the original bytes, which are then interpreted as UTF-8 text or binary depending on context.
The original payload may not have been UTF-8 text, or the string was URL-safe Base64 with different alphabet rules. Verify the source encoding and variant.
Many decoders strip whitespace automatically. If decoding fails, remove line breaks inside the Base64 string and retry.
JWT payloads are Base64URL-encoded JSON. You can decode the middle segment for inspection, but always verify signatures on the server for security.
Text ecosystems (JSON REST, HTML data attributes, logs) remain dominant. Base64 is a simple bridge when you cannot send raw bytes inline.
PEM wraps Base64-encoded binary in BEGIN/END headers, used for certificates and keys. You decode the inner Base64 to get DER or other binary structures.
No. Decoded bytes might contain script or markup. Treat decoded content as untrusted unless you escape it for the target context.
UTF-8 maps Unicode codepoints to bytes using a variable-width scheme. After Base64 decode, interpreting bytes as UTF-8 only works if the source was UTF-8 text.
Invalid alphabet characters, wrong padding, or truncated strings break Base64’s fixed 24-bit chunking. Fix the string or use a lenient mode if the tool offers one.
Hashing is one-way and detects tampering; Base64 is two-way and only changes representation. Do not confuse encoding with integrity guarantees.