Guides Locally AI

How To Replace Siri With a Free Local Model

In this guide, you will download a free AI model to your iPhone and connect it to your phone’s Action Button like Siri.

beginner 6 steps

Introduction

In this guide, you will download a free AI model to your iPhone and connect it to your phone’s Action Button like Siri. After setup, the model runs locally, so you can use it without an internet connection and without sending private prompts to a cloud service. The initial setup requires internet access and may take a few minutes while the model files download.

Do the model downloads on Wi‑Fi before you need the assistant offline. Most models are several gigabytes.

Step-by-step 6 steps

Instructions

  1. Step 1 of 6

    Download Locally AI

    Open the App Store and download Locally AI.

    Once it installs, open the app and continue through the welcome screen.

  2. Step 2 of 6

    Choose Your First Model

    When the app asks you to choose a model, start with the latest Gemma model available in the app.

    Pro tip: Do the downloads on Wi‑Fi before you need the assistant offline. Most models are several gigabytes.
    image-2194

    Gemma is Google’s open-source model family and is a strong first pick for this setup. It is good enough for normal assistant tasks and gives you a clean baseline before you start testing bigger models.

    Pro tip: Model names usually include sizes like 4B, 6B, or 8B. That number is roughly the model’s parameter count. Bigger usually means more capable, but it also means a bigger download and slower performance on your phone.
  3. Step 3 of 6

    Download and Test the Model

    Tap download and keep the app open while it finishes.

    This part may take a few minutes. That is normal. You are downloading the actual model file onto your phone, so it can be a few gigabytes.

    Once the model is installed, try one quick prompt before you connect it to the Action Button.

    Prompt
    Give me a quick plan for the three most important things I should do before a 30-minute client call.
    image-2198

    This test gives you a feel for speed and answer quality. If it responds well enough for quick assistant tasks, you are ready to bind it to your phone.

  4. Step 4 of 6

    Open Action Button Settings

    Swipe down on your home screen and search for Action Button.

    image-2199

    Open the Action Button settings. Swipe through the options until you see Shortcut.

  5. Step 5 of 6

    Choose Locally AI Voice Mode

    Tap whatever is currently set as the shortcut, then search for Locally AI.

    image-2200

    Select Voice Mode. Your Action Button should now be set to Locally AI Voice Mode.

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    Press the Action Button and wait for the chime. The first time you open Voice Mode, Locally AI may ask you to download a speech-to-text model. Download it.

    That speech-to-text model is what lets the app handle voice input locally. It is a separate download from the AI model itself.

    Pro tip: If Voice Mode does not launch right away, go back into the Action Button settings and confirm the selected shortcut says Locally AI Voice Mode, not New Chat.
  6. Step 6 of 6

    Test Your Local Assistant

    Press the Action Button and ask a question out loud. Try something practical:

    Prompt
    Explain the difference between local AI and cloud AI in simple terms.
    Prompt
    Translate "I will send the document this afternoon" into Spanish.
    Prompt
    Give me three ways to prepare for a quick client call.

    In testing, the local model was useful but not perfect. One smaller model missed a couple of basic factual questions. Local models are getting better fast, but they can still be less reliable than huge cloud models like those used in ChatGPT or Claude.

    For everyday assistant tasks, that tradeoff can still be worth it. Explaining concepts, translation, quick planning, and simple rewrites are all good fits.

    Pro tip: After the model and speech-to-text model are downloaded, turn on airplane mode and ask another question. If it still responds, you have proved the important part: the assistant is running locally on your phone.

You're done

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Overview Back to the steps

Background and context

Who This Is Useful For

  • iPhone users with an Action Button who want a better assistant shortcut than Siri
  • Privacy-focused users who want more AI tasks to run on-device
  • People curious about local AI who want an easy first model to test
  • Anyone who wants a quick voice assistant for explaining concepts, translating text, or working through small tasks

What You Will Build

You will turn your iPhone’s Action Button into a shortcut for an AI assistant that runs on your phone without needing internet or cellular connection after the model is downloaded.

IMG_3010
  • A Locally AI model downloaded onto your iPhone
  • Locally AI Voice Mode connected to the Action Button
  • A local voice assistant you can test with practical prompts

What You Need

  • An iPhone with an Action Button, such as an iPhone 15 or newer
  • The Locally AI app
  • 3+ gigabytes of storage space
  • Internet access for the initial model download
  • Wi‑Fi recommended for downloading several-gigabyte models

Going Further

  • Once the newest Gemma model is working, download a bigger model and run the same prompt through both. The point is not just to pick the “best” model in theory, but to find the model that is useful enough, fast enough, and private enough for the tasks you actually want a phone assistant to handle.
  • Compare how fast each model responds
  • Compare how much storage each model takes
  • Compare how accurate the answers are
  • Compare which one sounds better out loud