How to Update a Factorio Server and Pin a Version

Updating a Factorio server, pinning a version, and the save compatibility ladder that decides whether an old world still loads.

Updated September 12, 2026

Factorio

Your Factorio server's version is set by one field, and that field behaves differently from almost every other setting in the panel: its own description warns that changing it "will require a full server reinstall to change." That makes version choice a decision to make deliberately rather than a dial to nudge. This page covers what each accepted value resolves to, what a version change actually does to your files, and the order to do it in so you do not lose a factory.

The short version

Factorio Version accepts latest, experimental, or a specific version string. latest means current stable; experimental means the current experimental branch. Changing the field triggers a reinstall, so download your save first. Stay on stable unless you have a concrete reason not to.

What Each Value Resolves To

The field is not free-form magic — it maps onto Wube's own release feed at factorio.com/api/latest-releases, which publishes the current builds as plain JSON. That feed is what your Factorio server resolves the value against at install time.

Field value	Resolves to
`latest` (default)	The current stable headless build
`experimental`	The current experimental headless build
A version string, e.g. `2.0.77`	Exactly that build

Checked on 12 September 2026, that feed reports stable headless 2.0.77 and experimental headless 2.1.17. Those numbers move, so re-check the feed rather than trusting this table — it is a snapshot, and Factorio's release cadence is brisk.

A pinned version has to be a real published build. The wiki's Version history page is the canonical list of what exists, grouped by major version — currently up to the 2.1 line.

Stable Versus Experimental

Wube runs two tracks. Stable is what the vast majority of players and effectively all mod authors are on. Experimental is where new work lands first, and joining it means running a build your players' clients may not match.

That last part is the one that bites, because Factorio has no tolerance for a mismatch. The wiki states the rule for multiplayer without qualification: "All game instances need the installation of exactly the same game-versions and mods." There is no degraded-compatibility mode. A client on a different build does not get a worse experience; it does not connect.

Experimental is a one-way door on a rented server

Moving to experimental is a reinstall. Moving back off it is another reinstall — and a save written by a newer build will not load on an older one. If your group is not all willing to switch their clients to the experimental branch on Steam, do not put the server on it.

Mods compound this. Factorio mods declare compatibility with exactly one major version, and Wube's modding docs are firm that "Even if a mod would otherwise work on a newer major release, this field needs to be updated to explicitly mark it as compatible." Most authors do not target experimental early. How to install Factorio mods covers the compatibility rules in full.

Saves Go Forward, Not Back

This is the constraint that governs the whole process, and the wiki documents it precisely. Its install guide publishes a compatibility ladder showing which build loads which saves. The entries all take the same shape, and the current one reads:

"2.0.x: loads saves from 1.0.0 up to 2.0.x"

Note the upper bound. Every build loads saves up to its own version — never past it. A world written by a 2.1 server is outside the range a 2.0 build accepts, so reinstalling to an older version gets you an older binary but not a save that binary can read.

The ladder also shows the opposite limit. The wiki explains why old builds are still published: "Installing old versions is mostly useful to load old save files. The most recent version of the game cannot load very old save files, so it is necessary to download an older version, and resave the save file with it to upgrade it." Old worlds sometimes need a stepping-stone build to come forward. Archived releases are at factorio.com/download/archive.

Between them, those two facts mean the rollback you imagine having is not the rollback you have. Which is why the wiki's upgrade advice is the only step in this article that is genuinely non-negotiable: "It is recommended to create backups from this directory (of saves, config, etc) before installing a new version."

Changing the Version, in Order

Run /server-save from the panel Console. This writes the current world out immediately.
Download the save zip to your own machine. Not to another folder on the server — a reinstall touches the server. This is the step that makes the rest recoverable.
Download data/server-settings.json and the contents of mods/ if you have customised either.
Note what latest currently is. If you are moving from latest to a pin, you want to know the number you were actually on. Check the console output on boot, or factorio.com/api/latest-releases.
Set Factorio Version on the Startup tab and run the reinstall.
Re-upload your save and confirm Save Name still points at it.
Re-upload your mods to mods/, matching the new major version.
Start, and read the log. A version or dependency problem appears there before it appears anywhere else.
Tell your players. They need the matching client build, which for Steam users means opting into or out of the experimental beta branch.

A reinstall rewrites the server files

Treat anything you have not downloaded as gone. That includes your save, your edited server-settings.json, your mod zips and mods/mod-list.json.

When to Pin a Version

Pinning is the right call in three situations, and overkill everywhere else.

A mod your group depends on has not updated. Pin to the last build it supports and stay there until it does.
You are mid-campaign and want no surprises. A pin means the server does not move underneath a 300-hour factory.
Your players are on a specific build and cannot or will not update.

Otherwise leave it on latest. Stable releases are well tested, mod authors track them, and you avoid the reinstall cost of moving later.

latest is not a snapshot, it is a pointer

Leaving the field on latest means a reinstall for any reason will pull whatever stable is at that moment — which may not be the version your save and mods were built against. If that matters to you, pin the number.

Common Questions

Does my server auto-update to new Factorio releases?

No. The version is resolved when the server is installed, not on every boot, so a running server stays on its build until you reinstall. That is a feature — an unannounced version bump would lock out every player until they updated.

What version is my server on right now?

Run /version in the panel Console, or read the first lines of the startup log. Do not assume from the field value; latest means whatever stable was at install time.

Can I downgrade?

You can reinstall to an older build, but the wiki's compatibility ladder caps each build at saves "up to" its own version — so a world written by a newer server will not open on it. Downgrading only works if you kept a save from before the upgrade.

Will my mods survive the reinstall?

Assume not, and re-upload them. They also need to match the new major version — a mod marked 1.1 will not load on a 2.0 server regardless of whether the code would have worked.

My players suddenly cannot connect after a Steam update

Their clients moved and the server did not. Factorio requires exact version matching. Either they roll back their client, or you reinstall the server onto the matching build.

Is experimental worth it?

For a production group, no. For testing a mod against an upcoming release on a throwaway server, yes — and that is the right shape for it, a separate server rather than your main one.