Base64 File Converter
Convert files to Base64 and decode Base64 back to downloadable files entirely in your browser.
All conversion happens on this device. Your files and Base64 content are never uploaded.
Encode file to Base64
Choose a file or drop it below to generate a raw Base64 string.
Processing file...
Decode Base64 to file
Paste Base64 to reconstruct the original file and download it.
File preview
When to use this Base64 file converter
These common workflows match the way developers and IT teams use Base64 with real files:
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Embed an image in an email template
Convert a logo or icon to Base64 so you can inline it in HTML email without depending on external hosting.
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Inspect a Base64-encoded certificate
Paste encoded certificate data, reconstruct the file, and open it locally with the tool you already trust.
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Inline a font in CSS
Convert WOFF or WOFF2 files to Base64 for experiments with @font-face or single-file demos.
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Verify encode-to-decode round trips
Encode a file, decode the Base64 back to bytes, and compare the result when you need confidence in the workflow.
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Extract binary content from API payloads
Save Base64 attachments from JSON responses as real files without writing a one-off script.
Frequently Asked Questions
- How do I use this app?
- Enter or paste the required input, adjust any options, run the primary action, and review the result. Use the Clear/Reset control to start over.
- Is this app free to use?
- Yes. The app is free to use and does not require an account.
- What happens to my input data?
- The app MUST NOT store user-provided input. If any network request is required for a feature, the app MUST clearly disclose it in the Help section.
- Why am I getting an error or unexpected output?
- Most issues come from invalid input or incompatible options. Verify the input format, try the default settings, and use Clear/Reset before trying again.
- Where can I find instructions and troubleshooting tips?
- Use the in-app Help panel. It MUST explain inputs, options, and common mistakes, and it MUST be usable with a keyboard (including closing with Escape).
How to Use Base64 File Converter
How to use
Encode a file
- Choose a file with the picker or drag it into the drop zone.
- Wait for the browser to read the bytes and generate the Base64 output.
- Review the file metadata, then copy the Base64 string for your code, email template, CSS, or payload.
Decode Base64 to a file
- Paste a Base64 string into the decode panel.
- The tool validates the input, detects file details when possible, and enables download.
- Download the reconstructed file. Images also show an inline preview.
Tips
- Whitespace is ignored when you paste Base64 copied from JSON, logs, or certificates.
- Large files stay local to your browser, but conversion time still depends on your device and browser memory.
- Use Clear all before switching tasks if you do not want the current file or Base64 string to remain on screen.