The first thing that happens when you put mods on a Factorio server is that half your group can't get in. They hit join, the game thinks about it for a second, and then they get a wall of red text listing mods they don't have. Someone decides the server is broken. Someone else decides it's your fault. It's neither.
Factorio is stricter about mods than almost anything else we host, and the sooner your group understands that, the less of your evening you'll spend on it. So, two things before the list.
There's no such thing as a mod only some of you install. In Valheim or Conan you can hand one player a cosmetic mod and nobody else needs to care. Not here. The wiki puts it about as bluntly as a wiki can: "All game instances need the installation of exactly the same game-versions and mods." Factorio checksums every mod at startup and compares those checksums against every peer on join, which it has done since 0.12.30, and a mismatch of a single point release is enough to bounce somebody. Sounds miserable. It mostly isn't, because the client does the work for you: join a modded server, the game offers to sync, and it pulls the exact versions the server is running straight from the mod portal before restarting you into the game. Startup settings sync as well, though those sometimes want a second connection attempt and another restart before they take, which is the one part of the flow that reliably confuses people. Warn your group. They'll stop reporting it as a fault.
Match the release to your server's Factorio version, not to "latest". As I write this the stable branch is 2.0.77 and 2.1.15 is out on experimental, and a good few of the mods below now ship a 2.1-targeted release sitting on top of their 2.0 one. The portal keeps both. If your server's on stable, the big download button is not the one you want. Take the release whose Factorio version matches instead, because otherwise the server starts, quietly declines to load the mod, and tells you nothing useful until you go and read the log yourself.
Everything below I checked against mods.factorio.com the day I wrote this. Where the name everybody links is actually a dead package, I've said so and named the live one.
Quality of life
Squeak Through 2, by _CodeGreen
Walk between your pipes and assemblers instead of taking the scenic route around your own factory. Now the bit that matters: the mod everyone links, Squeak Through by Supercheese, hasn't had a release since February 2021 and it targets Factorio 1.1. It will not load on a 2.x server. Squeak Through 2 is the live one, it's been updated through this summer, and it explicitly declares itself incompatible with the original, so if an old guide talked you into installing both, there's your boot failure.
Even Distribution, by 321freddy
Drag a stack of coal across twelve furnaces and they each get the same share of it. Small thing on a solo save. Genuinely large thing on a shared server, where "I filled the first four boilers and forgot about the rest" is an entire category of confusing outage that nobody thinks to check for. Even Distribution has been going since 0.15 and picked up a 2.1 release in June.
Text Plates, by Earendel
Physical letters you place on the ground to label things. Sounds trivial, right up until you're the fourth person to wander into somebody else's oil setup wondering what on earth any of it feeds. Label the bus. Label the outposts. Label the thing that must not be switched off, in large friendly capitals, because somebody will otherwise switch it off. Text Plates costs you nothing.
Planning and diagnosis
Factory Planner, by Therenas
The ratio calculator, in-game. Tell it what you want per second and it works backwards through the recipe tree to machine counts and raw inputs, which on a shared server is mostly a way of settling arguments before anyone pours concrete. Factory Planner is under very active development: there was a release two days before I wrote this. Helmod does the same job behind a denser interface and has an equally long maintenance record, so which of the two you get along with is taste rather than correctness. Pick one. Not both.
Rate Calculator, by raiguard
Select a chunk of your factory and it tells you what that selection actually produces and consumes. Factory Planner tells you what you should have built. Rate Calculator tells you what you did build, and the gap between those two numbers is where most "why is the mall starving" arguments quietly end.
Bottleneck Lite, by raiguard
A small coloured light on every machine: green if it's running, red if it's starved, yellow if it's backed up. On a base with four people building in four directions, Bottleneck Lite is the fastest way to spot whose section has stalled without having to ask anybody. It's also the mod most likely to end an evening's confusion in about nine seconds.
Factory Search, by Xorimuth
Search the whole base for an item, a recipe, a machine or a circuit signal, and get map pings for every hit. The older and bigger your shared save gets, the more you'll reach for Factory Search. The classic use case: somebody built something two hundred tiles north eight months ago and nobody can remember where, or what it was for, or whether the belt going into it still matters.
Running a shared server
This is the category people ask us about most and the one where Factorio has the least to offer, honestly. There's no Pippi-equivalent admin dashboard here. The handful of "admin command centre" packages on the portal have download counts in the low thousands, which for a game this old tells you plenty, and I'm not going to put one in front of you on that evidence. Most of your real admin surface is base-game server settings and the console. What mods are genuinely good at on a shared server is coordination, so that's what these three do.
Todo List, by JasonMiles
A shared task board inside the game, synced across everyone connected. Assign jobs, tick them off, stop three people independently deciding to rebuild the smelter tonight. Todo List has been maintained since 2019 and it's about as close as Factorio gets to project management.
Milestones, by Wiwiweb
Records when your group hit each landmark (first steam engine, first blue science, first rocket) and timestamps them against playtime. Purely a morale thing rather than a functional one. On a community server that's been running a year, Milestones is one of the nicest additions you can make, and it costs you nothing but a zip.
Blueprint Sandboxes, by somethingtohide
Gives each player a private editor surface to design and test on, then lets them bring the finished blueprint back out into the real world. On a shared factory, Blueprint Sandboxes is the difference between somebody prototyping a new smelter block and somebody prototyping a new smelter block in the middle of your production line.
The big overhauls
Both of these are enormous, and the choice between them is mostly a choice about Space Age.
Krastorio 2, by raiguard
The gentler of the pair. New tiers, new buildings, a rebalanced tech tree and a proper ending, without asking anyone to relearn the game from scratch. Krastorio 2 reached 2.1 in June. If your server is on Space Age there's a separate merge project, Krastorio 2 Spaced Out by Polka_37, which is the maintained way to run the two together and shipped a release earlier this month.
Space Exploration, by Earendel
The huge one. Interplanetary logistics, a tech tree that runs for hundreds of hours, and a reputation it has thoroughly earned. Two hard facts before you plan a server around it.
First, Space Exploration is flat-out incompatible with Space Age. Not a soft warning, not a "some things may break". The mod names Space Age as an incompatibility in its own metadata and the game refuses to load the two together. Because Earendel now works at Wube, and because Space Age exists partly out of what SE proved could be done, an awful lot of people assume the two are a natural pair. They aren't. You're choosing.
Second, SE is not one file. It pulls in something like fifteen required dependencies: AAI Industry, Alien Biomes, Jetpack, Robot Attrition, five separate graphics packages and a handful more besides. Upload all of them. Miss one and the server will start and stop again immediately, with the log as the only place that says why.
If your server's on Space Age and what you want is more to do rather than something else to do, a content mod built on top of it is the healthier route. Cerys and Maraxsis are both actively developed, both add a new world with its own problem to solve, and both need every player on the server to actually own Space Age.
Getting these onto your LOW.MS server
Factorio mods don't go through Mod Manager here. There is a Factorio catalogue sitting in there, but it's a mirror that was last touched in 2019 (its copy of Warehousing is version 0.0.11, against 1.0.3 on the portal today), so read it as history rather than as an option. Everything real happens in the file system. That's fine, because Factorio's mod format is unusually friendly to exactly that.
- Download the
.zipfrom mods.factorio.com and don't extract it. Factorio reads the zips exactly as they come. - Log in to the LOW.MS Control Panel, open your Factorio service, and go to File Manager, then the
mods/folder. - Drop the zips in. For a large modpack, SFTP on port 8822 is far quicker than doing it through the browser, and an overhaul like Space Exploration is very much a large modpack.
- Open
mod-list.jsonin the same folder and check each new mod is listed with"enabled": true. - Restart from the panel. Mod changes aren't picked up on a running server.
Mod settings are the awkward part, because Factorio keeps them in a binary mod-settings.dat you can't sensibly hand-edit. The workaround is to install the same mods locally, configure them in your own game, and upload your mod-settings.dat over the server's copy. There's a fuller walkthrough in How to Install Mods on Your Factorio Server, and if you're running the DLC then Running Factorio Space Age DLC on Your Server covers how it turns up as its own set of mod entries.
A few habits worth picking up
- Take a Cloud Backup before every mod change, not only the ones that look scary. Pulling a content mod back out of a save it has already touched is how worlds die.
- Add mods in small batches and restart between batches. When the server won't boot you'll know precisely which zip did it.
- Read Log Viewer before you ask anybody anything. Factorio's mod errors are unusually specific and they name the file.
- Don't update the server on the day a Factorio release lands. Give the authors a few days.
- Agree a pinned mod set with your group and change it deliberately. Sync-on-join means everyone follows the server, so every change you make is a change you're making for all of them.
If it's already gone sideways, Factorio Server Troubleshooting covers the usual suspects, and if you're still shopping, our Factorio server hosting page is over here. Open a ticket if a modpack defeats you. I'd honestly rather help you get Space Exploration's dependency tree straight than watch you lose a weekend to it.