Base64 to Image Converter - Online Decode & Preview

A Base64 to Image Converter is a tool that takes a Base64-encoded string and decodes it back into a viewable image file. Base64 encoding is commonly used to embed images directly in HTML, CSS, JSON, or API responses. This tool reverses that process—simply paste your Base64 string, and it instantly renders the image for preview and download. It supports all major formats including PNG, JPEG, GIF, WebP, SVG, BMP, and ICO.

Simply paste your Base64 string into the input box above and click "Decode & Preview" (or wait for auto-detection). The tool automatically identifies whether you've pasted raw Base64 or a full Data URI (e.g., data:image/png;base64,...). Once decoded, you can preview the image, check its format and dimensions, and download it to your device with a single click. No data is uploaded to any server—everything happens locally in your browser.

This tool supports all common image formats: PNG, JPEG/JPG, GIF, WebP, SVG, BMP, and ICO. When you paste a raw Base64 string without a Data URI prefix, the tool automatically detects the format by reading the file's magic bytes. For Data URIs, the MIME type specified in the prefix is used. If format detection fails, the browser attempts to render the decoded data as a generic image.

A valid Base64 string contains only characters from the set: A-Z, a-z, 0-9, +, /, and optionally = for padding. The string length should be a multiple of 4. If your string contains other characters or has incorrect padding, the tool will display an error message. You can also look for the Data URI prefix (data:image/...;base64,)—if present, the actual Base64 data follows the comma. The tool validates your input and provides clear feedback if something is wrong.

Yes! This tool fully supports Data URIs. Simply paste the entire Data URI string (e.g., data:image/png;base64,iVBORw0KGgo...) into the input box. The tool automatically extracts the MIME type and the Base64-encoded portion, then decodes and displays the image. This is especially useful when working with images embedded in HTML, CSS files, or API responses that use the Data URI scheme.

Yes, this tool is completely safe and private. All decoding and processing happens entirely within your browser using JavaScript. Your Base64 string and the resulting image are never transmitted to any server. This means your data remains on your device at all times. You can use this tool offline once the page is loaded, and no third-party tracking or data collection occurs through the image conversion process.

Common issues include: (1) Extra whitespace or line breaks—try trimming the string. (2) Missing or incorrect padding characters (=). (3) Invalid characters outside the Base64 alphabet. (4) The string is truncated or incomplete. (5) The decoded data is not a valid image file—the string may encode something other than an image. If you're copying from a source with a Data URI prefix, make sure to include the full prefix. The tool provides specific error messages to help you diagnose the problem.

Base64 is a binary-to-text encoding scheme that represents binary data as a string of ASCII characters. A Data URI is a complete string that includes both a MIME type prefix and the Base64-encoded data, formatted as data:[mime-type];base64,[data]. For example, data:image/png;base64,iVBORw0KGgo... is a Data URI, while iVBORw0KGgo... alone is raw Base64. This tool handles both formats automatically.

There is no hard limit, but very large Base64 strings (tens of megabytes) may cause browser performance issues during decoding and rendering. As a practical guideline, strings up to 5-10 MB (approximately 7-13 million characters) should work smoothly in modern browsers. The tool displays the estimated decoded file size so you can gauge performance. For extremely large images, consider using a desktop image editor instead of a browser-based tool.