The most straightforward way to trigger a download is by creating a hidden anchor ( ) tag, setting its href to the Base64 data, and programmatically clicking it. The Implementation javascript
: revokeObjectURL ensures the browser doesn't keep the file in memory after the download starts. Handling Content Types (MIME Types) js download file from base64 string
function downloadBase64File(base64String, fileName) const link = document.createElement('a'); link.href = base64String; link.download = fileName; document.body.appendChild(link); link.click(); document.body.removeChild(link); // Usage const myBase64 = "data:application/pdf;base64,JVBERi0xLjQKJ..."; downloadBase64File(myBase64, "my-document.pdf"); Use code with caution. How it works : We create a temporary tag. The most straightforward way to trigger a download
💡 : If your Base64 string already includes the data prefix (e.g., data:image/png;base64,... ), you can extract the MIME type dynamically using a Regex or by splitting the string. Best Practices and Security How it works : We create a temporary tag
For a download to work correctly, the browser needs to know what kind of file it is receiving. Common MIME types include: : application/pdf PNG Image : image/png CSV : text/csv
: Works consistently across all modern browsers.