Data URL vs Raw Base64
A complete image Data URL carries both the MIME type and the Base64 payload, for example data:image/png;base64,iVBORw0.... That is the most reliable input because the page can preserve the declared type for preview and download.
Raw Base64 contains no MIME metadata. On this page, raw input is treated as image/png; the decoder does not guess JPEG, GIF, WebP, or SVG from file signatures. If the source is not PNG, use a complete Data URL so the correct MIME type and file extension are preserved.
What Happens During Decoding
The page removes surrounding whitespace, decodes the Base64 payload into bytes, and previews the result in the browser. Download creates a local Blob using the MIME type from the Data URL, or PNG for raw Base64 input.
If a value fails, check for copied quotes, a missing base64, marker in a Data URL, invalid Base64 characters, or a MIME type that does not match the data.
When to Use This Tool
Use Base64-to-image decoding when an API response, CSS snippet, JSON document, or debugging log contains an embedded image. Base64 is transport encoding, not compression: the encoded text is usually about one third larger than the original binary data.
For the reverse operation, use Image to Base64. For non-image Base64 text, use the general Base64 encoder/decoder. Processing and downloads stay in the browser.