The actual form would be http://web.mit.edu/~simsong/www/ugh.pdf#page=177 http://web.mit.edu/~simsong/www/ugh.pdf#page=177 For pdf.js (used by Firefox), refer

The actual form would be http://web.mit.edu/~simsong/www/ugh.pdf#page=177 http://web.mit.edu/~simsong/www/ugh.pdf#page=177 For pdf.js (used by Firefox), refer to https://github.com/mozilla/pdf.js/wiki/Viewer-options https://github.com/mozilla/pdf.js/wiki/Viewer-options If using Adobe Reader, refer https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pdfs/pdf_open_parameters.pdf#page=5 https://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/pd... (The second variant mentioned by you that works in Firefox using pdf.js appears to be a undocumented feature!)