What Is Base64 To File Decoder?
Base64 To File Decoder converts Base64-encoded strings back into their original files — images, PDFs, audio, video, documents, or any binary data. Paste a Base64 string or data URI, preview the result instantly, and download the decoded file. This tool runs 100% client-side. Your data is never uploaded to any server.
It supports automatic MIME type detection, inline preview for images, audio, video, and PDFs, hex dump inspection, custom filenames with auto-extension, drag-and-drop file loading, and detailed file metadata display.
How to Use This Tool
Paste or Load Base64
Paste a Base64 string or data URI into the text area. Or click 'Load from file' to import a .txt file. You can also drag and drop files onto the tool.
Decode & Preview
Click Decode & Preview to convert the Base64 back to its original format. The tool auto-detects the MIME type and shows an inline preview for supported formats.
Inspect the File
View file metadata (MIME type, extension, size) in the info panel. Toggle the Hex Dump to inspect raw binary data byte by byte.
Download
Edit the filename if needed, then click Download File. The file extension is auto-detected from the MIME type.
Features Explained
Data URI Support
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Paste a full data URI like 'data:image/png;base64,...' and the tool automatically extracts the MIME type and Base64 data. Raw Base64 strings without a data URI prefix are also supported.
Inline Preview
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Images are displayed as inline previews. Audio files get a playback control. Videos render in a player. PDFs display in an embedded viewer. Text and JSON are shown in a monospace pre block.
Auto MIME Detection
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The tool detects MIME type from data URIs and automatically maps it to the correct file extension (14 common types supported). Unknown types default to application/octet-stream.
Hex Dump View
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Toggle the hex dump to inspect the first 512 bytes of the decoded file. Each line shows the offset, hex values, and ASCII representation — useful for verifying file headers and binary data.
File Info Panel
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After decoding, a panel shows the detected MIME type, file extension, and exact decoded file size in a clean horizontal layout.
Drag & Drop
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Drag a .txt or .b64 file containing Base64 data directly onto the tool. The file contents are loaded into the text area automatically.
Load from File
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Click 'Load from file' to import Base64 from a text file (.txt, .b64, .base64, .pem). The file is read locally — nothing is uploaded.
Custom Filename
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Edit the download filename before saving. The tool auto-appends the correct extension based on the detected MIME type if no extension is present.
Common Use Cases
Decode email attachments
Email systems often encode attachments as Base64. Paste the encoded data here to recover the original file.
Inspect API responses
APIs sometimes return file data as Base64 strings. Decode and preview them to verify the content before integrating.
Recover embedded images
Extract images from data URIs found in HTML, CSS, or JSON files. Paste the data URI to preview and download the image.
Debug certificate files
Load PEM-encoded certificates or keys to inspect the binary content with the hex dump view.
Verify file integrity
Use the hex dump to check file headers (magic bytes) and confirm the file type matches expectations.
Convert data URIs to files
Turn inline data URIs from web pages into downloadable files with the correct extension.
Privacy & Security
This tool runs 100% in your browser. Your Base64 data is never sent to any server. All decoding, preview rendering, and hex dump generation happens locally using JavaScript.
No cookies, no analytics, no third-party services. Data exists only in your browser's memory and is discarded when you close or refresh the page.