Base64-Validator
Prüfen Sie, ob ein String gültiges Base64 ist – mit Padding-Status, Varianten-Erkennung und Größenanalyse.
Frequently Asked Questions
How do I know if a string is valid Base64?
Valid Base64 contains only A-Z, a-z, 0-9, + and / characters (or - and _ for URL-safe variant), with optional = padding at the end. The total length should be divisible by 4.
What are Base64 variants?
Standard (RFC 4648) uses + and /, URL-safe (RFC 4648 section 5) uses - and _, and MIME (RFC 2045) allows line breaks every 76 characters.
What does padding missing mean?
Base64 output should have a length divisible by 4, padded with = characters. Missing padding means = signs were stripped. Most decoders handle this, but strict parsers may reject it.
Can invalid Base64 still be decoded?
Sometimes. Missing padding can be auto-corrected. But strings with invalid characters or incorrect length will produce corrupt or garbage output.
Why does my Base64 have line breaks?
It is MIME-encoded Base64 (RFC 2045), commonly used in email. Line breaks are inserted every 76 characters. Strip them before decoding in most contexts.