FPDF - generated PDF is not displayed properly in browser - php

Question

I am generating a PDF document with a FPDF library.
I am trying to display a generated document in browser (Firefox, Chrome, Opera) but all i get are strange characters starting with:
%PDF-1.3 3 0 obj <>...
This is my code. I am trying to add two images to the document.
$pdf = new FPDF();
$pdf->AliasNbPages();
$pdf->AddPage();
$pdf->Image('./image.png',10,10,0,0,'png');
$pdf->Image('./image.png',10,120,0,0,'png');
$pdf->Output('file.pdf','I');
If I use the output with the 'D' option:
$pdf->Output('file.pdf','D');
and save the file on the disc, the pdf document is fine.

Answer 1

You probably need to add the correct content type header. When the web server serves up a file, it tries to give the correct content type header it guesses from the file, but here, as you're generating it with PHP, the default header will be sent, which is usually text/html. Try adding this to the start of your code:
header('Content-type: application/pdf');
And it should send with the correct content type header.

Answer 2

I run into the same problem and I add ob_get_clean(); before $pdf->OutPut() and I got the correct result.
It was because the header was not correct, but even I set the header before outputting the pdf, it still not correct.

Answer 3

change D to I
$pdf->Output('file.pdf','I');
send the file inline to the browser. The plug-in is used if available. The name given by name is used when one selects the "Save as" option on the link generating the PDF.
from there documentation
fpdf documentaion

Answer 4

Add exit as follows :
$pdf->Output();
exit;
Reference

Answer 5

Try:
ob_start (); //used before output.
$pdf->Output();
?>

Answer 6

I don't know if i should put it as a comment or answer, i had same issue on my localhost, but once i placed my code on live server the issue resolved automatically. Try cleaning all cookies on your local system and it may help too.

Answer 7

I had applied all the above options with different sequences and this is how finally it works. Thanks
$str = iconv('UTF-8', 'windows-1252', $custom_data);
$final = html_entity_decode($str ,ENT_QUOTES, 'windows-1252');
$pdf = new FPDF();
header('Content-type: application/pdf');
$pdf->AddPage();
$pdf->SetFont('Courier','',16);
$pdf->MultiCell(190, '10', $final, '', 'L');
ob_get_clean();
$pdf->Output($afterDash.".pdf", "I");
exit;