Convert large pdf to text

I am working with large pdf , having 3k pages , I want to convert pdf to text, so how can I extract text from the pdf , the code which I was working before is not able to convert or extract text from pdf more than 100 pages. below is the Code sample .

using (var writer = new StreamWriter(txtDocumentStream))
{
	var textAbsorber = new TextAbsorber();
	pdfDocument.Pages.Accept(textAbsorber);
	await writer.WriteAsync(textAbsorber.Text);
	writer.Flush();
	txtDocumentStream.Position = 0;
	await _UploadBlobFromStream(txtDocumentStream, txtMediaPath);
}

suggest the efficient and fastest way to perform the operation

@abdulkadirsabirbohari

In order to make the process faster, you can absorb text on page level like below sample:

foreach(var page in doc.Pages)
{
  // extract text and save into file
}

In case you face any issues, please share your sample file with us so that we can test the scenario in our environment and address it accordingly.