Base64 Validator

Validate and inspect Base64 strings

Input

About Base64 Validation

Paste any Base64 string to check its validity and inspect its structure. The validator detects invalid characters, padding errors, and estimates the decoded file size.

Data URI — detects if the string is a full data:...;base64,... format and extracts the MIME type. URL-safe — checks if the string uses -_ instead of +/.

A text preview is shown when the decoded content is readable plain text. Binary files show a “not available” message.