Decode Base64 online.
Paste Base64 text or open a file. Standard Base64, Base64URL, missing padding, and Data URI input are handled locally.
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Drop a text or binary file anywhere in the converter.
Your input and results are processed only in this browser. They are not uploaded to or stored on a server.
How to decode Base64
Base64 is an encoding format, not encryption. Anyone who has the value can decode it.
- Paste a Base64 value or open a file that contains one.
- The tool detects the format and applies common corrections such as removing whitespace or restoring missing padding.
- Copy readable text, or download binary output as a file.
Your input is not stored.
The site does not store your input or conversion results, and it does not send them to a server. Everything is processed in your current browser session and disappears when you reload or close the page.
Standards and input handling
By default, the tool follows RFC 4648 and handles standard and URL-safe alphabets, optional padding, MIME whitespace, and Data URI prefixes. Turn on strict validation when the exact format matters.
Frequently asked questions
Is Base64 encryption?
No. Base64 changes binary data into printable text. It provides no secrecy or authentication.
Why can't I read the decoded output?
The output may be a file, compressed or encrypted data, or text in a different character encoding. Try downloading the file or choosing another character encoding.
Does this site upload my input?
No. Conversion happens in your browser. Your input, files, and results are not uploaded to a server.