Base64 Decoder
Paste a Base64 string or data: URL to get the original content back. Text is shown directly; images are previewed and binary files such as PDFs or ZIPs can be downloaded.
Runs in your browser
How to use
- Paste the Base64 string or data: URL.
- Read the decoded text, or preview the detected file.
- Download the file if it is binary.
How it works
The decoder accepts standard Base64 and Base64URL, with or without = padding, and ignores whitespace and line breaks. A data: URL prefix is stripped automatically.
The decoded bytes are checked for a file signature (magic bytes) to recognise PNG, JPEG, GIF, WebP, PDF and ZIP. Otherwise they are decoded as UTF-8 text.
Examples
- Text
- SGVsbG8sIHdvcmxkIQ== → “Hello, world!”
Common uses
- Reading Base64 values from APIs, emails and logs
- Extracting images from data URLs
- Inspecting encoded configuration values
Privacy & security
This tool runs entirely in your browser. Your files and text are never uploaded to our servers — processing happens on your device and results are created locally. How each tool handles files
Frequently asked questions
Why do I get “not valid Base64”?
The string contains characters outside the Base64 alphabet or is truncated. Make sure you copied it completely.
Can I decode a JWT here?
You can decode each part, but the JWT Decoder shows the header and payload as formatted JSON directly.
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