In my experience, this has been hands down the most consistent html to pdf add_on in Firefox. It seems like I only recall a single instance where it failed to perform. Other than that it has consistently and faithfully reproduced html documents in pdf format. The only caveat is that if the Open radio button is chosen the browser window will automatically close after the converted document downloads and will subsequently restart. It's a small inconvenience; so I normally click the Save option. It's one of the best add_ons in Firefox! Reading through some of the other reviews on the product, it's obviously a hit and a clear favorite. Because of that I have in addition bookmarked the website https://www.printfriendly.com