LXQt is the merger of the Light X11 Desktop Environment (LXDE) based in GTK and the razor-qt desktop environment based in Qt, both serving similar purposes - to provide a very lightweight DE that is still relatively modern and functional. Does it live up to this, however? Let's find out!
Warning that once again, I am my own person with my own opinions. Don't rage PM me ("all the DEs suck but DWM/xmonad sucks less" in particular will earn an instant block, fuck off) or anything like that, but suggestions are of course always welcome, particularly if I get something wrong. That being said, each experience will obviously be different.
Also worth noting, I am testing Lubuntu 20.04 on a 2010 Toshiba Satellite p845-s4200, i5 1st Gen running @ 2.6000 GHz. I am also testing it on a 2016 Asus Vivobook E403SA, Pentium @ 2.4000 GHz. As always I will be primarily testing the DE on an Ubuntu flavour unless stated otherwise. The only way to give a truly in-depth review for me is to use it as a daily driver and Ubuntu tends to be best for my use case. Expect some DEs to be tested on other distros tho (most notably GNOME which I'll base my experienced off of Fedora and Ubuntu and XFCE which I'll base off of Artix and Xubuntu).
Accidentally delted my screenshots but I got:
The DE was also astoundingly smooth - even running this on my weak ass Pentium, it never slowed down a bit, even with a ton of tabs open for school (which has the heavyweight Google Drive, Classroom, YouTube, etc. as well as Discord). It definitely is the best out there for lower computers. In general, I do have a rule of thumb - if it can't run LXQt, you probably need to dump the machine and get a new one (if you really can't dump it, OpenBox or IceWM by itself is fine on a Debian/Ubuntu minimal install, Artix would probably be best there since no systemd leads to less resource usage and it otherwise has all the packages you'd need, if it can't run that it won't run modern tasks well at all and is honestly not functional).
In terms of CPU usage I've noticed that it tends to be quite low. This Pentium is horrendously weak but it rarely overloads itself even with multiple browser windows and other applications open, which is quite rare for this machine. It handles windows quite efficiently and I can open as much as I want with no downside. As seen in the CPU monitor that the panel had, it only really surged up to high usage when I opened something new and otherwise was consistently below 10%.
Another thing I've noticed is battery efficiency. A focus on battery life is incredibly rare amongst Linux DEs (ironically many of the lightweight DEs are horrendous with this, XFCE is a notable example) but LXQt manages that quite well. I don't even have TLP installed but it lasts around 10 hours or so which is similar to Xubuntu's performance with TLP. I do recommend TLP in any case however, it's fantastic and will buff battery life immensely.
Overall LXQt really lives up to its reputation as a lightweight and well-performing DE. A huge part of this is Openbox, which is just a fantastic WM. I don't recommend changing to another WM if you wish to keep performance.
I came in expecting the functionality to not be good at all as the cost for better performance. I was pleasantly surprised to find out I was quite wrong there. LXQt really does keep up with other DEs by default iwth functionality, though it does not go past that.
The menu and panels work just as you'd expect. They offer the standard set of applets (however, the panel configuration menu doesn't seem to include the network manager applet for whatever reason) and all of these work reasonably well as you'd expect. There's not much to really say regarding these, except that unfortunately, neither off anything beyond what is there by default. Personally, I prefer something akin to XFCE's Whisker Menu or KDE Plasma's menu over the bare-bones menu LXQt has, and there's really no way to change it. Likewise, xfce-panel has more applets and you can even extend it, whereas LXQt does not have that.
This trend stays with the default apps. Most of these apps are lightweight and do what they need to and not much else. These tend to work pretty well for the most part. Unfortunately, it also sometimes relies on KDE apps as defaults which tend to be significantly more bloated and heavier. Again, none of these apps really do mucb beyond what it says on the tin. While it's naturally compatible with most KDE apps - after all it is a Qt based DE and KDE runs the Qt game on Linux - it's not great to have to install such bloated software.
With this being said, however, it does come with some poor defaults. It doesn't suspend or even lock the screen upon being closed by default, which is beyond stupid. Without keyboard shortcuts, there is no easy way to change the brightness. Some of hte apps are also not the most intuitive, most notably PCManFM which just is overall janky with its flow. As a whole, some design choices can only be summed up as random and unintuitive. It's easy enough to configure it to what you want to be though.
LXQt gives what you need up to the level of other DEs by default, but it does not go past that the same way others do. It's more than functional enough for what it gives though.
I won't lie, I wasn't expecting too much coming into this - it is a relatively lightweight distro after all and I didn't expect much in the way of features. But yet, LXQt does it and does it well - it doesn't give too much but it gives just what you need.
Most of the customization is on the end of Openbox. Really, it's a fantastic WM and imo one of the greatest strengths of LXQt. It makes configuration absurdly easy while being very powerful. You can change the workflow to just about anything you want it to be and get more or less functionality to go with it.
In terms of the settings center itself... there's really very little that changes much. You can fix some of the bad defaults but that's really all you can do, which is fine seeing the design philosophy of the desktop. This puts it well behind its competitors, however, which spoil you with choice.
That being said, there's really not much you can do with it. There's no extra bells and whistles as is the aim. Compared to MATE/Xfce/KDE, it's definitely far less configurable. It doens't really shine here, but it's not bad for the resource usage you get.
LXQt, surprisingly, has quite the nice aesthetic (though in all honesty almost everything with LXQt is surprisingly good to where its not really surprising). I'm on Lubuntu and by default, the Arc theme, Ubuntu font and ePapirus icon creates a slick, modern and colorful look. OpenBox by default looks quite nice with its borders and it's easy enough to change if desired. Even the default themes from screenshots I've seen look decent enough.
Unfortunately, Lubuntu doesn't have too much in the way of additional themeing. There's no (good imo) Solarized theme in particular, which to me is a huge bummer. This does limit it in terms of looks to what you can really salvage. What's there is quite good, however. In addition, the default look that other, non-Lubuntu distros have is not great, and you will need to download additional themes in order to make it work. Even on Lubuntu, I'd recommend doing so just in case. The additional themes primarily come from OpenBox themes and Qt themes. OpenBox has some decent ones but there's nothing special, while Qt you won't be getting much. The situation isn't great there, but at least the aesthetics are decent enough by default - particularly on Lubuntu - to make this worthwhile.
Regarding themeing, things aren't so great. There is no way to theme Qt apps by default. You instead need to install Kvantum, which is a themeing engine that will do so for you. Install both it & the themes, which should be in a package (on Lubuntu this is qt5-style-kvantum and qt5-style-kvantum-themes). Then, open it up and choose the theme you want (wip)
LXQt is honestly much better than its often portrayed. It's definitely the lightest DE out there, even when compared to XFCE (which on Xubuntu should just be called midweight), MATE (which isn't quite as light...) etc.. However, it is surprisingly still decently featured. It has customizability, functionality, aesthetics and more up to par other heavier DEs defaults, though it never manages to go past that. A lot of this really has to do with Openbox - it is an absurdly good WM as I've stated multiple times and is perfect alongside LXQt. I can confidently recommend LXQt for just about any machine out there if you don't plan to do much beyond a standard use case of primarily going on the web and doing a select few limited desktop tasks, or if you have a gaming machine and want all the RAM you can possibly get. I rank it quite highly amongst the Linux DEs for its sheer lightness.
That being said, it really falters when you go beyond the first impression. There are some very poor defaults (why does it not suspend when I close the laptop?) and it lacks a lot of default applications of its own. The ones it has are very very good, but they're not enough in general. The only real solution is to rely on either GTK ones (which may introduce bloat with their GTK-exclusive tools) or KDE/Deepin apps (which are just naturally super bloated). This takes a toll over time. It also does not have very much beyond the default configuration. You can't really make it your own nearly as much as you could with Xfce, MATE and KDE - it has far fewer themes and customization options, and you're basically stuck with the default panel plugins and what OpenBox gives. All that LXQt has over them is less resource usage, which really does come at a cost. As a result, it's great for light usage of the desktop itself - either you're spending most of your time on the internet browsing or you're gaming - but when it comes to using a ton of local apps, it falls behind its competition.
As for distros, I have only tested Lubuntu but it's still probably the best choice out there. Fedora Spins tend to be pretty bad (messy, lacks a lot of features you'd really expect, not too well integrated and overall feels like they're just Fedora with the DE slapped on them with minimal testing done and Fedora imo is worse than Ubuntu) and thus I generally advise against them, and while I suppose Debian might work with LXQt but really it's just outclassed by Lubuntu seeing that they have the same issue. If you really want to go lighter with LXQt, Artix has an image for it by default. It doesn't use systemd nor does it make some heavier choices Ubuntu does, which leads to it being incredibly lightweight. Be warned that Lubuntu 18.04 LTS does not use LXQt - it is the last of the Lubuntu versions to use LXDE instead (which tbf isn't a bad choice but its hardly developed anymore). 20.04 is the best to use LXQt with.
||Decent - it keeps on par with other DEs defaults but does not go beyond||Again, decent - keeps on par with defaults, doesn't go beyond||Great with Lubuntu, decent regardless. Limited in choices though.||A fantastic balance between the "meat" of a DE and extremely low resource usage.||Mid-High, hampered primarily by not being able to do much beyond what you're given and some poor defaults.|