Factorio 2.1 stable: what is known, what is not

No, Factorio 2.1 is not stable yet, and Wube Software has not said when it will be. On 22 October 2026 Wube's own release API answers stable 2.0.77 and experimental 2.1.23. The 2.1 update has been public since 23 June as an opt-in branch, and in those 121 days it has had 17 builds. The last statement on timing is from Wube's 26 June Friday Facts post: "we still have plenty of time before we plan to mark it stable". This page sets out what the records show on the day of writing, how long Wube's two earlier experimental runs took, why the mods matter, and what is still unknown. For the game itself, start with our Factorio explainer.

Everything below was read on 22 October 2026. The script in code/factorio-2-1-check.py re-reads the release API, the wiki's 2.1 history and the game's Steam posts, and marks any figure that has changed since. Run it after Wube's next announcement and it will say whether 2.1 has gone stable:

python factorio-2-1-check.py
python factorio-2-1-check.py --mods

Where 2.1 stands on 22 October 2026

Wube's records agree on the current version numbers:

The game's Steam news feed says the same thing another way. Wube posts there when a version goes stable, and the newest such post is "Version 2.0.77 released as stable" on 23 June 2026. None of the 350 Steam posts we read names 2.1 as stable. The stable branch itself has not moved since 23 June. That is 121 days, the longest stretch between stable posts since 2.0 launched with the Space Age expansion in October 2024. The previous longest was 96 days, from 2.0.76 on 19 March 2026 to 2.0.77.

What Wube has said about the stable date

Three statements, all from Wube, and none of them a date.

On 29 May, in Friday Facts #440, Wube wrote that "we plan to keep 2.1 as experimental over the whole summer (I.E, not mark it stable), so that mod authors will have plenty of time to update." The same post called 2.1 the end of active development: "We envision 2.1 as our last major update of Factorio". After 2.1 Wube plans to work on bug fixes, platform support and modding.

On 26 June, in Friday Facts #444, the post announcing the experimental branch: "please don't expect us to be changing things in too much of a rush, we still have plenty of time before we plan to mark it stable, and we will make any decisions and tweaks thoughtfully." The same post said Friday Facts would no longer keep "any specific schedule". Since then there have been four: #445 on 7 August, #446 on 18 September, #447 on 25 September and #448 on 9 October. We read all four and none of them gives a stable date.

Every release thread on Wube's forum ends with the same line: "New versions are released as experimental first and later promoted to stable." So 2.1 will not arrive as a separate download. Wube will promote one of the experimental builds, and the stable branch will update to it.

The summer Wube named is over and 2.1 is still experimental. That is the only firm point on timing. It does not tell us whether stable is weeks away or months away.

Seventeen builds in four months

The archive, the forum and the wiki all start the public 2.1 line at 2.1.7, on 23 June. Friday Facts #445 calls that build "the initial 2.1.0 release", so earlier numbers were probably internal. Wube has not said so, and we have not assumed it. We counted every line of the 17 release changelogs on the forum and checked each date against the wiki. All 17 dates match. The counts are in the data file that ships with this page:

The first build carries 651 of the 1,143 lines. The other 16 builds add 492 lines between them, and 354 of those are bug fixes. The longest gap between builds is 21 days, from 26 August to 16 September. The median gap is 5.5 days. The 2.1.18 and 2.1.19 builds came out on the same day, as did 2.1.15 and 2.1.16. Friday Facts #446 says the Steam-side work for the ARM64 Linux build went live in 2.1.15, and that "there was one major bug which necessitated a hotfix".

The Lines column counts every bullet, including the modding and scripting sections (49 and 42 lines after 2.1.7), which are aimed at mod authors rather than players. "Features" adds Wube's "Features" and "Minor Features" headings together.

Gameplay was still changing in October

For seven weeks the builds added no features and no balance lines: from 2.1.14 on 6 August to 2.1.20 on 22 September, those two columns are zero. Then on 6 October, 2.1.21 changed gameplay again: six minor features, including an index comparator for the selector combinator and "Read empty slots" for containers, plus two balance lines, "Retuned asteroid damage" and "Adjusted space platform drag to be based on weight rather than width".

Friday Facts #448, three days later, explained both. Asteroid damage was reworked for 2.1 so that an asteroid's remaining health decides how much damage it does. After player feedback that building platforms in Vulcanus orbit was "too punishing", 2.1.13 cut damage to stationary platforms by 90%: "A medium asteroid could previously do 3200 damage to a platform in orbit; after this change, it was only 320." In 2.1.21 a medium asteroid "now deals 2000 damage to a moving platform and 100 to a stationary one", which the post compares with "approximately 67" for a stopped platform in 2.0. The drag change goes further, and the post says so: "2.1 has been in experimental for quite some time now, and since this change retroactively affects all existing platforms, I apologize that this wasn't done earlier in development."

The two builds since, 2.1.22 and 2.1.23, are bug fixes, one optimisation, and modding and scripting lines, with no new features or balance changes. Two quiet builds are not a stable announcement, and we do not treat them as one.

How long the earlier experimental runs took

Wube has run the same experimental-then-stable cycle before. These are the two cases where both ends have a clear date in Wube's own records:

The 0.17 dates come from the Steam posts "Version 0.17.0 released" and "Factorio version 0.17 - Now stable", and from Friday Facts #314: "We released 0.17.69 as stable this Tuesday." The wiki dates 0.17.0 to 26 February 2019 as well. The 1.1.0 date comes from the wiki. The Steam post of 3 December 2020 agrees with it ("Last week we have started the experimental cycle"), and the 29 January 2021 stable post says the game "will/should auto-update to 1.1.19".

Two other updates are left out on purpose. 0.18 has no "now stable" post in the Steam feed; the next milestone there is "Version 1.0.0 released" on 14 August 2020. 2.0 was not an opt-in run. It shipped with the expansion, and Steam has "Version 2.0.7 released" on 21 October 2024 and "Factorio Version 2.0.9 now stable" two days later.

Two data points are not a forecast. They show only that 2.1 has now run longer than all of 1.1's experimental cycle, and for about 58% as long as 0.17's.

The mods question

Wube gave mods as the reason for the long experimental period, and the 1.1 stable post shows the same reasoning in 2021: "Its been 2 months since the 1.1.0 release, so most mods should have been updated." So we counted where the mod portal stands. Wube's mod API returned all 24,047 mods on 22 October. For each one it gives the lifetime download count and the game version its latest release declares:

Among the most popular mods, most authors have already released for 2.1. Further down the list, most 2.x mods still stop at 2.0. Three limits apply. Download counts are lifetime totals, so the ranking favours old mods, which is why some top mods still stop at 1.1. A mod whose latest release says 2.0 may or may not load in 2.1; we did not check that, and Wube's own warning is only "Mods you rely on may not be updated yet." And Wube has not said what share of updated mods it is waiting for, so these numbers say nothing about the date.

What 2.1 adds

Friday Facts #440 set the scope as quality of life, small features, fixes and polish, and modding improvements, and ruled out "new planets", "new enemies" and "new research trees or resource chains". The 2.1.7 changelog fits that scope. Its 43 feature lines include flipping for pumpjacks, burner mining drills and inserters (so blueprints flip properly); circuit network connections for pipes, storage tanks, boilers, heat exchangers, labs, land mines and heat pipes; requester and buffer chests that can set requests and read contents at the same time; patrols for spidertrons; and warnings when two different fluids are about to be connected. For Space Age owners, orbital requests can import from any planet or from other space platforms, small requests can be batched into one rocket, and quality now raises storage tank volume, cargo wagon size and locomotive power. Of the 20 balancing lines, eight are about shotguns, including piercing shell damage "from 8 to 12" and shooting speed "from 1/s to 1.5/s". The space platform hub's health rose from 1,000 to 5,000.

Fifty-seven of the 651 lines in 2.1.7 carry Wube's Space Age marker. Those changes reach only players who own the expansion.

If you opt in now

Friday Facts #444 lists what switching means, and the list still applies:

• "2.0 save games will load, but there may be changes that break your factory designs."
• "Once updated, blueprints and save games cannot be downgraded to 2.0." Wube recommends backing up saves and blueprints first.
• "There may be further gameplay changes and tweaks." 2.1.21 was one.
• "Mods you rely on may not be updated yet."

How to switch, in the post's words: on Steam, "Right-click Factorio in the library → Properties... → Game Versions & Betas → Experimental"; in the version bought from Wube's site, "Settings → Other → Enable experimental updates"; or download the experimental package from the download page. The same post raised the Linux minimum to GLIBC 2.36 for the standalone build ("Headless and Steam versions are not affected") and the macOS minimum to 10.13. One group has no choice. Friday Facts #446 says that on Steam, "Factorio for ARM64 Linux is available on the experimental branch (version 2.1)". The stable download page offers no arm64 build; the experimental page does.

What is not known

• The date 2.1 will be marked stable. Wube has given a window that has passed ("over the whole summer") and a phrase ("plenty of time"), nothing more.
• Which build will be promoted. Wube's forum says builds are "later promoted to stable", so it will be one of the experimental builds, but not which one.
• Whether more gameplay changes come first. The last ones were on 6 October.
• Whether, or when, the Nintendo Switch and Switch 2 versions receive 2.1. Nothing in Friday Facts #440 to #448 or in Wube's Switch 2 announcement says, and we did not read Nintendo's store pages.
• How many players are on the experimental branch. Wube does not publish that figure.

The data file and the script

datasets/factorio-2-1-releases.csv has one row per 2.1 build, 17 rows, with these columns:

Factorio already has a row in the site's games dataset from the September explainer, so this update does not add a second one. The script prints the current branches, the build count and gaps, the newest stable post on Steam, the two earlier runs beside 2.1, and with --mods the mod portal table above. Run it with --saved and a folder of saved copies to repeat the 22 October numbers without going online.