Free Image to Data URI Converter

How this tool computes its result

Converts an uploaded file to a Data URI using the browser's native FileReader.readAsDataURL (which handles base64 encoding and MIME-type detection automatically). In the reverse direction, it parses a pasted Data URI, checks for a ';base64' marker in the metadata segment via regex, and either decodes the base64 payload into a Uint8Array with atob() or, for non-base64 URIs, runs decodeURIComponent on the raw payload — either way wrapping the bytes in a Blob using the MIME type extracted from the 'data:<mime>' prefix, then triggering a browser download named by that MIME subtype.

Worked example

Uploading a small PNG produces a string like data:image/png;base64,iVBORw0KGgoAAAANSU... Pasting that exact string into the input field and clicking 'Download image from Data URI' calls dataUriToBlob, which detects the ;base64 flag, decodes it with atob(), and downloads a file named data-uri-output.png (the '.png' extension is derived from splitting the MIME type 'image/png' on the slash).

When not to use this tool

The image preview only renders for strings that literally start with 'data:image/' — pasting a technically valid Data URI for a non-image MIME type (for example, data:application/pdf;base64,...) will still decode and download correctly through the dedicated button, but it will never show a visual preview.

Common mistakes

• - Pasting a string into the decode field that doesn't start with the literal prefix 'data:' — downloadFromDataUri explicitly checks source.startsWith('data:') and shows 'Data URI input must start with data:.' otherwise, even if the rest of the string is valid base64.
• - Assuming the 'Copy Data URI' button copies whichever field has focus — it always prefers the freshly generated Data URI from a file upload over anything manually typed or pasted into the textarea.
• - Pasting a very large Data URI (multi-megabyte image) — unlike the CSV tool's 2 MB file-size cap, there is no size guard here, so huge base64 strings can make the textarea noticeably sluggish.

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