Paste a string to validate if it is properly Base64 encoded. Get detailed diagnostics including character set analysis, padding check, and decode test.
A valid Base64 string contains only characters from the Base64 alphabet: A-Z, a-z, 0-9, + and / (or - and _ for URL-safe variant). The string length must be a multiple of 4 when properly padded with = characters.
Common issues include trailing whitespace, line breaks, or characters outside the Base64 alphabet. This validator checks all these conditions and attempts to decode the string to confirm it produces valid binary data.
Common reasons include: spaces or line breaks in the string, characters outside the Base64 alphabet (like @, #, or !), or incorrect padding. The validator will tell you exactly what's wrong.
Technically, proper Base64 requires padding to make the length a multiple of 4. However, many implementations accept unpadded strings. This validator considers unpadded strings as 'valid but missing padding.'
URL-safe Base64 replaces + with - and / with _ to avoid conflicts with URL special characters. This variant is commonly used in JWT tokens, data URIs, and filenames.
Codifique ou decodifique strings Base64 diretamente no seu navegador
Converta texto para Base64 ou decodifique Base64 para texto simples
Converta imagens para strings codificadas em Base64
Decodifique strings Base64 de volta para imagens visíveis
Codifique qualquer arquivo para uma string Base64
Decode any Base64 string back to its original file
Decodifique strings Base64 para documentos PDF
Decodifique e inspecione tokens JWT
Codifique ou decodifique URLs com codificação percentual
Converta caracteres especiais em entidades HTML
Converta entre formatos hex e Base64
Decode Base64 strings to plain readable text
Decode Base64 and pretty-print as formatted JSON
Generate Base64 data URIs from text or files