text model · Gemma · iOS

Can I run Gemma 3 12B on iPhone 15 Pro?

Compatibility verdict VRAM threshold engine

No, not enough memory would not load

No. Gemma 3 12B needs ~8.9 GB even at Q4_K_M, but iPhone 15 Pro only has ~4.5 GB usable.

Needs ~8.9 GB Device usable ~4.5 GB

Needs ~8.9 GB even at Q4_K_M, but only ~4.5 GB is usable.

That figure is at a 4k context and moves about ±15% as context length changes.

The gap is about 4.4 GB: Gemma 3 12B needs roughly 8.9 GB at Q4_K_M and iPhone 15 Pro leaves only about 4.5 GB usable for a model. The lightest tracked hardware that runs Gemma 3 12B is the Nvidia GeForce RTX 3060 (12GB) at 12 GB. See Gemma 3 12B on Nvidia GeForce RTX 3060 (12GB).

Q4_K_M needed: ~8.9 GB
Usable on device: ~4.5 GB
Device memory: 8 GB

Share on X Share on Reddit

Which quant fits

Quant ladder vs ~4.5 GB usable

Q2_K

~6.6 GB

Q3_K_M

~7.5 GB

Q4_K_M

~8.9 GB

Q5_K_M

~10.2 GB

Q6_K

~11.4 GB

Q8_0

~14.1 GB

FP16

~25.6 GB

The line marks iPhone 15 Pro's ~4.5 GB budget; rungs past it are too large.

How to run it

On iOS use Apple Foundation Models (Built into iOS 26, ~3B on-device model, zero download, fully private.).

Model Gemma

Parameters: 12B
Q4_K_M size: 7.3 GB
Q8_0 size: 12.51 GB
Context: 128k
Ollama tag: gemma3:12b

Full Gemma 3 12B requirements →

Device iOS

Memory: 8 GB unified
Usable for weights: ~4.5 GB
Power draw: ~14 W
Best runtime: llama.cpp + Metal (via PocketPal or Off Grid app)

Best models for iPhone 15 Pro →

What you can run instead

Run Gemma 3 12B on other hardware

Nvidia GeForce RTX 3060 (12GB)Nvidia GeForce RTX 4070 (12GB)Apple M2 (16GB)Apple M4 (16GB)Nvidia GeForce RTX 4060 Ti (16GB)Nvidia GeForce RTX 4080 (16GB)

FAQ

Can iPhone 15 Pro run Gemma 3 12B?

No. Gemma 3 12B needs ~8.9 GB even at Q4_K_M, but iPhone 15 Pro only has ~4.5 GB usable.

How much memory does Gemma 3 12B need?

iPhone 15 Pro does not have enough memory. At Q4_K_M the weights are ~7.3 GB; with KV cache and runtime overhead, budget ~8.9 GB at a 4k context.

What is the best tool to run Gemma 3 12B on iOS?

On iPhone and iPad, Apple Foundation Models (Built into iOS 26, ~3B on-device model, zero download, fully private.) is the standard choice. Phones realistically run 1B-4B class models. Anything larger thermally throttles or OOMs.

Embed this

A live badge for your model card or README, updated as the data is.

Markdown

[![Gemma 3 12B on iPhone 15 Pro](https://localmodel.run/badge/gemma-3-12b/iphone-15-pro.svg)](https://localmodel.run/can-i-run/gemma-3-12b/iphone-15-pro)

Sources

Weights are measured from GGUF files; KV cache and overhead are computed, so totals can vary ~15% with context and runtime. Any tok/s is a bandwidth estimate. See methodology.