Base64 decoder
Decode Base64 encoded text or files
Max file size: 5 MB · Drop file here or click to upload
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How Base64 decoding works
Decoding turns Base64 text back into the original bytes. Every 4 characters become 3 bytes, and the padding at the end tells the decoder how many bytes the last group holds. The result can be readable text, such as JSON, or binary data, such as an image or a PDF that was embedded in an email, an API response or a data URL.
This decoder accepts standard and URL-safe Base64 and ignores spaces and line breaks. It reads the first bytes of the result to detect JPEG, PNG, GIF and WebP images, which it previews, as well as PDF and ZIP files. You can read the result as UTF-8, ASCII or Latin-1 text, or download it as a file. Decoding happens in your browser.
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How to decode Base64
- Paste the Base64 string, or upload a text file that contains it.
- Check the detected type: text, image or binary data.
- For text, change the encoding if characters look wrong.
- Copy the text, or download the result as text or as a file.
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Base64 decoder FAQ
- Can I decode a Base64 image?
- Yes. Paste the Base64 string and the decoder detects JPEG, PNG, GIF and WebP from the first bytes and shows a preview. Use Download as file to save it with the right extension. If your string starts with a data URL prefix, such as data:image/png;base64, remove everything up to and including the comma first.
- Why do I get an invalid Base64 input error?
- The input contains characters outside the Base64 alphabet, or its length cannot be valid. Common causes are a data URL prefix left in place, quotes or other text copied around the string, or a value that was cut short. Spaces and line breaks are ignored, and URL-safe minus and underscore characters are accepted.
- Why does the decoded text show strange characters?
- Either the data is binary, such as an image or a compressed file, or it was encoded with a different character set. Try switching between UTF-8, ASCII and Latin-1. If the detected type is binary data, the content is not meant to be read as text; download it as a file instead.
- Is my data sent to a server when I decode it?
- No. Decoding, file type detection and image previews all happen in your browser tab. The Base64 you paste and the files you upload are not sent to a server or stored, and downloads are created on your device.
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