Base64 Image Converter

What is Base64 Image Converter?

A Base64 Image converter transforms data between an image file and a Base64-encoded data URI. Base64 is a binary-to-text encoding scheme that represents binary image data as an ASCII string, typically formatted as a data URI (data:image/png;base64,...). This allows images to be embedded directly in HTML, CSS, JSON, or XML without a separate file request. This converter supports bidirectional conversion: Image to Base64 produces a data URI from an uploaded file, and Base64 to Image decodes a data URI back into a viewable, downloadable image.

How It Works

For Image to Base64, the tool uses FileReader.readAsDataURL to read the uploaded file as a Base64 data URI, then loads it into an Image element to extract dimensions and size for the preview. For Base64 to Image, the tool parses the input string, prepends a default data URI prefix if missing, loads it into an Image element to validate and extract metadata, and renders the preview. All processing is local and private.

Common Use Cases

• Embedding images inline in HTML emails or single-file web pages
• Inlining small images in CSS background-image to reduce HTTP requests
• Storing image data in JSON or XML configuration files
• Inspecting or recovering an image from a Base64 string
• Generating data URIs for use in markdown or documentation that supports inline images

Technical Details

Image to Base64 uses FileReader.readAsDataURL which returns a data URI string. Base64 to Image parses the data URI, extracts the MIME type via regex, loads it through an HTMLImageElement to validate and read naturalWidth/naturalHeight, and estimates byte size from the Base64 length (length * 3/4). The tool enforces a 5MB file size limit for uploads. Object URLs are revoked to prevent memory leaks. The converter runs entirely in the browser with no network requests.