Paste your Base64 string below to reconstruct and download the original file safely.
100% Local processing. No data is sent to servers.
Decoding is crucial when you receive binary data wrapped in JSON from AI APIs (like Vision or DALL-E models). By converting the Base64 string back to its original format (PNG, JPG, PDF), you can verify the output, store it locally, or perform post-processing. Our PureAINav decoder handles this without needing a backend proxy.
The tool looks for the Data URI prefix (e.g., data:application/pdf;base64,...). If present, it automatically extracts the MIME type and suggests a file extension. For raw Base64 strings, you can manually input the MIME type to ensure the browser treats the downloaded file correctly.
Base64 strings often represent sensitive documents, identification photos, or internal logs. Traditional online decoders upload your string to their server, creating a security risk. uBase64 Decoder uses the Blob and URL.createObjectURL APIs to decode and trigger downloads purely in your local browser memory.