PDFs in Amazon S3 don't open in Chrome for view
If you want the browser to treat the file as pdf you should let him know that his file is a pdf. The way to do so is to send the relevant header:
Content-type: application/pdfThe current header that is sent by s3 is:
Content-type: application/octet-streamSince you upload the files to s3 - you can either set the correct mime-type for the file during uploading or afterward, using some of the s3 tools (for example s3cmd for windows).
According to the link to the documentation you provided, the putObjectFile function is deprecated, but this is the definition:
putObjectFile (string $file, string $bucket, string $uri, [constant $acl = S3::ACL_PRIVATE], [array $metaHeaders = array()], [string $contentType = null])As you can see - the last parameter is contentType - so you can set it to application/pdf when uploading the file.
This will set the correct header when downloading.