Help with Enabling Range Requests for Linearized PDFs

[javim89]

Hello everyone,

I have a question about optimizing the preview of a PDF file over 100MB in my application. It’s a linearized PDF, and as I understand, PDF.js should allow range requests (partial downloads). You can see an example of this in Mozilla's viewer, where the partial requests (status 206) are flowing in:

https://mozilla.github.io/pdf.js/web/viewer.html?file=https%3A%2F%2Fs3.amazonaws.com%2Fpdftron%2Fdownloads%2Fpl%2F2gb-sample-file.pdf

This works as expected in the Mozilla example, but I haven't been able to achieve the same behavior using this library.

My PDFs are hosted on S3, which supports range requests, and I’m using the following code to load the PDF:

<Document file={docUrl} onLoadSuccess={onDocumentLoadSuccess}>
  {Array.from(new Array(pdfNumPages), (el, index) => (
    <Page key={`page_${index + 1}`} pageNumber={index + 1} />
  ))}
</Document>

From what I understand, this code should automatically support range downloads if the PDF is linearized, but it doesn’t seem to work. The first page doesn’t render until the entire PDF is downloaded.

I also tried adding a manual Range header:

<Document
  file={docUrl}
  onLoadSuccess={onDocumentLoadSuccess}
  options={{
    httpHeaders: {
      Range: "bytes=0-",
    },
  }}
>
  {Array.from(new Array(pdfNumPages), (el, index) => (
    <Page key={`page_${index + 1}`} pageNumber={index + 1} />
  ))}
</Document>

but the issue persists. Could someone guide me on how to resolve or improve this?

Thanks in advance for any suggestions!

[javim89]

For anyone else who has a similar problem, I had the S3 configuration wrong.

This configuration helped me solve the problem.

#1691 (comment)