How the format is detected
Every image format starts with a signature, often called magic bytes: PNG files begin 89 50 4E 47, JPEG FF D8 FF, GIF "GIF8", WebP "RIFF…WEBP". The tool decodes your Base64 and reads these bytes, so it works even when the string has no data:image/… prefix or the prefix is wrong.
You get the detected type, pixel dimensions and file size, and a download button that saves the file with the correct extension.
Frequently asked questions
Do I need the data:image/png;base64, prefix?
No. Paste with or without it. If it is present, it is ignored and the real type is detected from the bytes.
Why is nothing shown?
The data may be truncated (common when copying from logs), or it is not an image. The tool reports which: invalid Base64, or valid Base64 whose bytes do not match a known image signature.
Is it safe to preview SVG?
SVG is rendered through an <img> element, where browsers block scripts inside it, so previewing is safe.
Are images uploaded?
No. Decoding and preview happen entirely in your browser.