Short answer
To remove a page from a PDF, type its number (e.g. 3), choose your file, and download the new PDF without it. It's free and runs entirely in your browser, so nothing is uploaded.
Deleting a stray page — a blank, a cover, a duplicate — is the most common edit. Enter the page number, or a list like '1,4', and the rest of the document is preserved in order.
The new file is built on your device, so a confidential PDF never leaves it.
Enter its page number (the total page count) and download — that page is removed and the rest kept.
No — pages are removed in your browser.