The Sims Mod Manager

Hi! This is the official blog for The Sims Mod Manager, a free and open source app that handles mods for The Sims 1, The Sims 2, The Sims 3, The Sims Medieval and The Sims 4 in one place. Windows, Mac and Linux.

Install, enable, disable and sort your mods without ever opening the game folders yourself. It finds your Mods folder on its own, including when the game sits somewhere the launcher never put it and when the folder name is in your language rather than English. Drop a zip, a rar, a 7z or a .sims3pack on the window and it unpacks everything to where that game reads it. Disabling just renames the file so the game skips it, so nothing you own ever gets deleted.

It pulls the artwork out of your .package files too, so the library looks like your mods instead of a wall of file names. And it'll tell you when two mods are overwriting the same thing, when a folder is buried too deep for the game to load it, and when something you have installed is known to be broken.

It reads your saves as well. Every save the game wrote, backups included, opened without opening the game: each household with its funds and its house, who lives there and how they feel about each other, the photos your Sims took, and the numbers for the whole world, from population and net worth down to the highest skill anybody in it has. It only ever reads. Nothing in a save gets written, renamed or moved.

It handles your packs now as well, the ones EA sold you rather than the ones you downloaded. Every expansion, game pack, stuff pack and kit you own on one screen with its own artwork, and in The Sims 4 the names come out of the installer in whatever language you play in.

You can switch them off from there. In The Sims 4 the app writes the same setting the game's own pack screen writes, so the two agree with each other; in The Sims 3 it goes through the registry, Windows only, and it needs administrator rights, which it tells you rather than letting a switch snap back. Nothing on disk moves and nothing gets deleted either way, so turning one back on puts it back. The game only reads its pack list when it starts, so whatever you change is waiting for you at the next launch.

The Sims 2 Legacy Collection can do it too, sitting behind a toggle in Settings because a neighbourhood opened without a pack it was played with is the quickest way to lose a Sims 2 save, so back yours up first. The Sims 1 lists what you have and leaves it there, since its expansions installed straight into the base game.

Ten languages, dark mode, and the Sims 1 UI sounds if you want them.

There's also a shop in the app, The Exchange, and it exists for the people making the mods. Upload from the portal on the site, write your page the way you want it (bold, italics, links, the formatting you'd get anywhere else), pick your own screenshots, call your version whatever you call it. Push an update and everyone who installed it hears about it. Your name is on the card and so is the number of people who have actually downloaded it, counted properly, one machine once a day, nothing estimated. Releasing the same thing in eight shades no longer means eight cards on the shelf either: give the set a name and the colours gather under one, each still its own page and its own link. Every mod gets a link that opens straight to it inside the app, so you can post it wherever you already post. No queue to sit in, nobody taking a cut, no feed deciding who deserves to be seen. It's your page.

Download now for Mac, Windows and Linux. It's free!

The app has a Packs screen now. It lists what EA sold you next to what you downloaded: expansions, game packs, stuff packs and kits, each one with its own artwork, its pack code and what it's costing you on disk.

Where a game has a safe way to run without a pack, there's a switch next to it. The Sims 4 writes the same packstoskipmount line the game's own Pack Selection screen uses, so the two agree instead of fighting each other. The Sims 3 takes the pack out of the registry the launcher reads, which is Windows only and needs administrator rights. The Sims 2 switches sit behind an opt-in in Settings marked experimental, because a neighbourhood played with a pack can break when it's opened without one, and that's a thing to switch on deliberately rather than find by accident. The Sims 1 merged its expansions into the base game back in the day, so there the screen is a list.

Nothing gets moved, renamed or uninstalled either way. A pack you switch off is still sitting on your drive, the game just stops loading it the next time it starts. Useful if you want a lighter game, or if you're trying to work out which pack a mod is really fighting with.

Sims 4 players who own every expansion and every game pack get a little something on that screen. Not saying what.

The rest of the release is smaller. The library sorts by name, date or size now, and can push disabled mods to the bottom. It reads CC Magic's .off marker, so packages an old manager switched off don't disappear from the list any more. And it finds your Documents folder when OneDrive has moved it somewhere else, which is where a good chunk of the "it can't find my game" reports were coming from.

@friendofbellas asked if I'd be interested in a Greek translation. I said yes, obviously. Then they went and did it, all 158 strings, checking things with me as they went.

The setup help for each game is in there, and the long paragraph about why two of your mods are stepping on each other, which cannot have been fun.

Eleven languages now, nine of them from simmers who offered. Which is roughly how the whole app gets built. plumbtreemods is the reason Sims 1 files land in the right folders, bunsenpixel worked out why the macOS window kept opening solid white, and a good chunk of everything else turned up because simmers offered to help however they could. I couldn't have asked for a better community.

Ευχαριστώ, @friendofbellas 💚 This project is as much yours as it is mine.

hey, thank you! false positives with Defender are pretty common for smaller indie apps like this, mostly because we're not signed with an EV certificate (the expensive kind of code signing that tells Windows "trust me"), so any new build looks a little suspicious to it at first. there's no single install folder though, it depends on how you installed it:

Used the installer normally? it's probably at C:\Users\yourname\AppData\Local\Programs\The Sims Mod Manager

Picked "install for all users" during setup? then it's C:\Program Files\The Sims Mod Manager

Grabbed the portable zip? wherever you unzipped it, no fixed spot

quickest way to check for sure: right click the app's shortcut and hit "open file location." that jumps straight to the right folder.

Yes, the original game from 2000. Mods for The Sims 1 live next to the game files instead of in Documents, and the manager knows that. If you still play the classic and try this early version, tell me how it goes.

Download for free on Windows, Linux and Mac

There's a Saves screen in the app. It reads the save files the game wrote and shows you what's in them, without loading the game.

Pick a save and you get its households, with what they have in the bank, how many rooms the house has, who lives there, and the portraits the game itself drew. There's a photo album of the pictures your Sims took, and a page of stats for the whole world: population, net worth, life stages, the highest skill anybody has, what the save actually costs on disk. Backups show up as well, so you can see all four copies The Sims 4 quietly keeps.

How much you see depends on the game, because it only shows what the game really stored. The Sims 2 keeps the most by a long way, down to family trees, degrees and majors, and the hobby your Sim was born for. The Sims 1 gives you families, their houses, and how everyone feels about everyone. The Sims 3 barely writes anything about individual Sims, so there you get the world, the household and its portrait.

It never writes. The files are opened read-only, and nothing in a save gets renamed or moved.

Also new: on The Exchange your name is on your listings, every listing counts its downloads, and colour variations of the same mod gather under one card instead of filling the shelf.

Testing whether a mod is breaking your game? Don't delete it. The manager renames it so the game skips it, and one click brings it back. Nothing is ever deleted. Early days for this app, so feedback is very welcome.

Thanks! Added in v2.1.2: there's a Refresh button on the library now, next to the grid/list/folders switcher. Hit it after copying mods in and they show up. Tysm for your support!

v2.0.0 is out and the app has a shop in it.

It's called The Exchange, it sits at the bottom of the sidebar, and it holds mods for all five games at once. The chips across the top filter it down to whatever you're playing. Press Install and the file goes into the right folder for the game that mod was made for, even if you're looking at a different game's library right then. No zip, no unzip, no guessing between Mods and Downloads.

It's an alpha, so the shelves are thin. Publishing is free, there's a portal for it on the site, and whatever goes up shows in the app for everybody.

Every mod on the shelves also has its own page now, in all ten languages, with the cover art and the creator's install notes. Share that link wherever you post and it works for your whole audience, not just the part that already has the manager. One button opens it in the app, one goes and gets the app, one just downloads the file the way you always have.

The app keeps track of what it installed, too. When a creator puts up a newer version, that mod grows an Update badge in your library and the sidebar counts how many are waiting.

Nothing to do with the shop, but the other big one this release is the broken-mod warnings. After a game patch, the app can tell you which of your mods other players have reported broken. The list gets downloaded, the matching runs on your own machine, and nothing about your library leaves it.

Free, no account unless you want to publish. Windows, Mac and Linux.

Download it here.

Your .package files have artwork hiding inside them. The Sims Mod Manager digs it out and shows you actual thumbnails instead of a wall of identical file icons. Still an early version, so if a thumbnail looks wrong on your setup, I'd love to hear about it.

v1.1.0 is out, and it's for anyone who doesn't keep their games where the launcher put them.

If your Sims 1 or Sims Medieval lives on a second drive, in a custom Steam library or in some Games folder you made years ago, the app never found it. It checked a few fixed paths under Program Files and then shrugged and asked you to point at the folder yourself.

Now it reads the library list Steam keeps, then walks your drives a few folders deep and looks for the game's actual files. Sims.exe sitting next to GameData for TS1, Game/Bin/TSM.exe for Medieval. Folder names are ignored on purpose, because disc copies come with translated names, every re-release renames something, and a copy you moved yourself is called whatever you felt like that day. It gives up after a while too, so a sleeping external drive can't freeze the app.

Two annoyances also gone. Deleting a mod while the game still had it open used to throw a useless error, now it retries and then tells you in plain words. And a rar it can't open says so instead of looking like a crash.

Free, no account, Windows Mac and Linux.

Download for free on Windows, Linux and Mac

Hey guys, Felix here. Some people asked me about my position on AI generated apps and where this project inserts on all of that.

I work as a software developer at a company that is very, very into AI. I have watched people I sat next to get let go and not replaced, because an AI licence costs less than a salary. Every time it happens I wonder when it's my turn. So that's where I'm writing this from.

Which isn't to say I hate the thing. I use it every day. It writes documentation in a language that isn't my native one. It comments a method so that someone who shows up in six months can actually help me. Copilot autocomplete finishes the boring block I've typed a thousand times already. It also drinks the ocean, which nobody likes to put on the slide but if everyone learns to use it more responsibly this topic would be lighter.

It still isn't an employee.

Vibe coding is when you describe what you want, paste back whatever the model hands you, and ship it without reading it. Which would be fine if it stayed a toy. But this is software people install on their own machine, pointed at folders they've been filling for years now. Mine can delete files. If I don't understand my own code, I'm gambling with someone else's Downloads folder.

It also makes the rest of us look replaceable, which is exactly the argument being used to walk my colleagues out of the building.

I drew this one by hand in draw.io for the post. Although this one is very very very very simple and lacking technical details (don't want to give you traumas), I don't do it nearly as often as I should and I won't pretend diagrams are part of my routine, but that's sort of the point. I'd love to watch someone who vibe coded their whole app open a blank canvas and draw their own architecture even in this simplified way, arrows and all, without screenshotting the folder tree and calling it a diagram.

Two bugs got reported on github recently. Both are closed now (hopefully for good, otherwise I'll be reopening them and eating my words).

The first one came from someone with 45,201 mods installed. Linux killed the app for eating too much memory, which also skips every mechanism that would have written a log, so there was nothing to read. The culprit was my own conflict detection. It compares packages by their internal resource keys and built a pair for every combination sharing one. Sims 2 creator tools stamp the same ids into every file they ever export, so that library came out at roughly two billion pairs (I know, crazy!), rebuilt from scratch on every single toggle (NASA computer over here). The tab lag on top of it was the filter chips recounting all 45,201 mods on every repaint, about 478ms a frame. (That number is off my own machine with a fake 45k folder built to match. I never got to see theirs.)

The second one was a Mac on macOS 10.15 where the app died before a single line of my code ran. I asked the reporter to launch the binary from the terminal, because the one error line that mattered never makes it into Apple's crash report. It said the isolate snapshot was invalid. Flutter changed how it packages compiled code in 3.44 and the new format isn't readable on Catalina or Big Sur. Not my bug. It's flutter/flutter#189183, still open upstream, so I pinned my release builds to an older Flutter and shipped.

Ask a model to fix "app crashes with many mods" and you'll get a try/catch around the symptom and a paragraph telling you it's solved. Neither of those was ever going to come out that way.

There's no GetX in this project. No state package at all, just one ChangeNotifier and ListenableBuilder doing the work. I like GetX. Four years of Flutter every single day since 2022 and I still reach for it on small things. But I'm not building something I want to maintain for years on a package the community is quietly walking away from. That's a judgement call about trust and momentum, and a model that has read every GetX tutorial ever written will cheerfully tell you it's fine.

I'm also doing my masters in CS right now, and it's noticeable how much responsible AI use has crept into subjects that have nothing to do with AI. That's the right instinct. Nobody is telling students not to use it. They're being taught to be accountable for what comes out.

This whole thing is a love project anyway. The Sims 2 was my first computer game and the one I properly fell for, the best one in the franchise, and I won't be taking questions on that. I had the four-disc Deluxe pack and I treated those discs like treasure. Anyway. You don't hand something like that to an autocomplete and hope.

And none of this protects me, by the way. Knowing my own code line by line either made by me or assisted with AI hasn't made anybody at work harder to replace. That's the part I don't have an answer for, so I'm not going to pretend the post has one.

So use the tool. Let it write your docs, let it finish your boring blocks and basic modules. Then read every line it gives you like it came from a stranger, because it did.

And study, for god's sake. Even if you don't enjoy coding, be good enough to review it, test it, and know when the machine is lying to you with total confidence.

v1.0.15 is out and the lights are off.

Dark mode, finally. Every screen of it, and the games keep their own colours down there, so Sims 2 is still blue, Sims 3 still green and Sims 4 still mint. Light, Dark, or follow your system so it flips on its own when the sun goes down.

It also speaks ten languages now. English, 简体中文, Español, Português (Brasil), Français, Deutsch, Italiano, Русский, Polski and 日本語.

Not a half job either. Setup screens, mod categories, buttons, error messages, and even the dates and file sizes get written the way your language writes them. It picks up your system language on its own, and there is a picker in Settings if you would rather read it in something else.

Everything else is where you left it. The Sims 1, 2, 3, 4 and Medieval in one window, free, open source, Windows, Mac and Linux.

so previously the conflict detector was basically a guy squinting at file names going "hmm. hair_v1.package and hair_v2.package. suspicious." which, correct, but not exactly forensic.

now it actually opens the package and reads the resource keys inside. type/group/instance. it knows when two mods are fighting over the same resource even if the file names are completely unrelated. it knows.

and it will tell you. it will tell you 79 times.

click one and it explains itself like a very polite bomb disposal expert: here is the other version, here is why the game loads them in an order nobody can predict, please pick one.

it also notes that overlaps can be intentional (patch mods exist, we're not monsters) so you don't nuke something on purpose. but be honest. you have four versions of the same vest. you know you do. i know you do. i had to look at a screenshot of it to write this post.

other things in 1.0.12:

linux/steam deck people: it now finds your Documents folder inside wine/proton prefixes. steam compatdata, flatpak, heroic, lutris, plain old ~/.wine. previously it looked in ~/Documents, found nothing, and quietly assumed you didn't own the sims. sorry.

toggling a mod while the game has it open no longer explodes with a windows error message in whatever language windows felt like that day. it waits a moment, tries again, and if the file genuinely vanished it just says so in a human sentence.

crash reports no longer contain your file paths. turns out "an error occurred" was helpfully attaching C:\Users\YourRealFirstName\...\thirst_trap_hair_FINAL_v3.package for context. it now sends .package and nothing else. the app has learned discretion. it did not have discretion before. we don't have to talk about it.

the settings toggle is now called "Scan inside mods" because "scan for artwork" was underselling what it's doing in there.

anyway. 1502 mods. 79 conflicts. no judgement. (some judgement.)

I got tired of digging through my Mods folder in Windows Explorer trying to remember which .package file was the broken one. So I built a mod manager that works across The Sims 1, 2, 3, Medieval and 4. It's an early version, so if something feels off, tell me. I genuinely want the feedback.