Tesla's Optimus Gen 4 to Be Built at Giga Texas, Fremont Lines to Be Stepping Stone

A few days after announcing the discontinuation of the Model S and Model X, Elon Musk said this is only the warm-up. The production lines for the Model S and Model X in Fremont are being repurposed to produce Optimus Gen 3.

Optimus Gen 3 will be built in Fremont, while the next-generation Optimus (Optimus 4) will be produced in Austin at Giga Texas.

Looking Even Further

On X, Elon explained the choice to use the older Fremont facility for Optimus, noting the site has required multiple retrofits and upgrades to support automation.

During the Earnings Call, Elon said Optimus (gen 3), which will occupy the former Model S and Model X space, will target a final annual capacity of 1 million units. The future line in Texas is expected to reach much higher volumes, likely up to 4 million units per year by the end of 2027.

That same Texas line is ultimately planned to scale to 10 million units per year, assuming Tesla’s plan proceeds as expected.

Optimus 4 will be built in Texas at much higher volume

— Elon Musk (@elonmusk) January 29, 2026

Gen 3 vs Gen 4

The roadmap for Optimus is shaping up as two main phases.

Phase 1 will have Fremont producing Optimus Gen 3, using the footprint from the Model S and Model X lines. That line will tackle the initial challenges of mass-producing Optimus, including the complex, entirely new supply chain required for a bespoke humanoid robot.

Phase 2 will place Giga Texas as the site for the more widely available Optimus Gen 4. That Texas line will have about three to four times the Fremont line's initial capacity and up to 10x its final capacity once fully expanded.

Texas is the New HQ of Autonomy

The move centers Giga Texas in Tesla’s autonomous strategy. The Austin factory is expected to house much of Tesla’s AI-related infrastructure and production lines, whether that be the brains (Cortex 1 and 2), the wheels (Cybercab), or the bodies (Optimus Gen 4).

Fremont remains an important manufacturing hub near Tesla’s engineering and design studios, but it increasingly looks like a legacy facility used transiently to test and commission new lines with engineers nearby to resolve issues.

Keep Iterating

Tesla has not officially unveiled Optimus Gen 3, which is scheduled for this quarter, yet Elon is already planning manufacturing for Gen 4. Tesla intends to apply initial field learnings from Gen 3 to the Gen 4 model to make it easier to mass-produce.