$fpdf->Output( 'D', "filename.pdf") return pdf string to browser instead of forcing download

Question

I merged multiple pdfs using fpdf, storing it locally to a path works fine. I want to skip storing and download the pdf straight from memory. I used the following in a service :

//All had the same outcome (returned pdf string to the browser *see imager)
$fpdf->Output( 'D', "filename.pdf")
$fpdf->Output( 'I', "filename.pdf")
$fpdf->Output( 'S')

Using:

• PHP 7.4
• Laravel 8
• setasign/fpdf (1.8.6)
• setasign/fpdi (v2.6.0)

I tried:

$fpdf->Output( 'F', "path/filename.pdf")
return response->download("path/filename.pdf")

$output =  $fpdf->Output( 'S');
        
return Response::make($output, 200, [
       'Content-Type' => 'application/pdf',
       'Content-Disposition' => 'attachment; filename="merged.pdf"',
       ]);

same issue, it returns the pdf string to the browser.

Answer 1

1. Verify the response headers, not the content alone.
2. Your Browser may also interfere, when being set as default pdf viewer.

When the response headers tell you,

Content-Disposition attachment;filename="xy.pdf"

then you are okay.