Context: I've been using my Firefox profile for a couple of years now. My history file has become huge, naturally. I got Firefox Sync set up between my main desktop PC and my laptop. HW configs: PC: i5-3450, 8 GB DDR3 RAM, Crucial M4 128 GB SSD laptop: Pentium SU4100, 4 GB DDR3 RAM, WD 5400 rpm HDD Accessing history entries when typing into the Awesome Bar on my desktop takes quite a long time despite the decent config, the laptop is even slower. The experience is quite unresponsive. I figured if I cleared the history up a little bit, I might avoid creating a new profile to speed things up. The question itself: to illustrate: Is there a way to delete all history entries that have been visited fewer than x (let's say 5) times and at the same time the recent visit is fewer than y (let's say 120) days old? afaik the history file is some kind of SQL database, but I'm not really sure how the data is saved, if there's a "safe way" to edit it and what the query to do what I need would look like. Thanks in advance for any help. I kept browsing through previous SuperUser questions to see if I could find relevant information. "In my Firefox profile directory, there is a filed named places.sqlite. Opening it with sqlite reveals (amongst others) the tables moz_places and moz_historyvisits. It seems that moz_historyvisits uses the primary of moz_places to refer to the URLs." As I'm unfamiliar with databases, I don't really understand the way the two tables mentioned in the quote are related. screenshot of a part of the tables I've noticed the visit_count is in a standard format, making it easy to work with. The last_visit_date looks encrypted to my naked eye, but I can't see in which way. Hope that helps, I'm at my wits' end.