Base64 Validator
Validate Base64 strings, detect file types, and preview content.
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How to Validate Base64
- 1Paste your Base64 string into the input field.
- 2The tool automatically validates the format.
- 3View the detected file type (MIME type) and size.
- 4Preview the content if it is an image or text.
Common Use Cases
Debug API Issues
Check if the Base64 string received from an API is valid and complete.
Identify File Types
Determine what kind of file a Base64 string represents (PNG, PDF, etc.).
Check Data Integrity
Verify that a Base64 string is not corrupted or truncated.
Preview Content
Quickly see what is inside a Base64 string without decoding it manually.
Frequently Asked Questions
What constitutes a valid Base64 string?
A valid Base64 string consists of characters A-Z, a-z, 0-9, +, and /. It usually ends with = or == for padding. It must not contain whitespace (though our tool handles that).
How does the tool detect the file format?
It looks for "magic numbers" (specific byte sequences) at the beginning of the decoded data that identify file formats like PNG, JPEG, PDF, etc.
Can I validate large strings?
Yes, but extremely large strings might slow down the browser. The tool is optimized for typical web use cases.
Is my data safe?
Yes, all validation happens locally in your browser. Your data is never sent to any server.