Local AI is artificial intelligence that runs directly on your device instead of remote servers. A local AI model processes your prompts on your machine. Nothing is uploaded, so it stays private, works offline, and is free of usage fees. The trade-off used to be complexity: runtimes, model files, command-line tools. Sigma removes that step by building local AI into the browser: you download a model once and use it in AI Chat, on any page, or with the browser agent.

Is local AI as good as ChatGPT?

For everyday tasks like questions, summaries, writing, and translation, modern local LLMs are surprisingly close to cloud models, and they respond instantly because nothing travels over the network. The largest cloud models are still stronger on complex reasoning, long documents, and specialized coding work. That's why Sigma doesn't force a choice: run a local model for private everyday work and switch to a cloud model for heavy tasks anytime, right from the same chat.

Can you run AI locally for free?

Yes. In Sigma Browser, local AI is completely free: download a model and use it with no API fees, subscriptions, or usage limits. Since inference happens on your own hardware, there is no per-request cost and no provider metering your usage. The only real “cost” is disk space for the model file and some RAM while it runs, and you control both by choosing a model size that fits your machine.

What are the best local AI models?

The best local AI models balance quality and hardware requirements. Smaller models are fast and light enough for laptops and phones; larger ones produce better answers but need more RAM. In Sigma you can run models like Hermes and OpenClaw locally: download one right in the browser and start using it immediately, no separate tools required. If you already use another runtime, connect your own model via API key instead.

How do you run AI locally?

Traditionally you'd install a runtime, download model weights from a hub, configure paths, and wire everything to your apps. In Sigma it's built in: download the browser, get a local model in one click or connect your own via API key, and start chatting. The model then works everywhere in the browser (AI Chat, page summaries, the agent) with no terminal, no config files, and no separate app to keep updated.

What is the difference between local AI and cloud AI?

Local AI processes everything on your device: private by design, offline-capable, and free to use once the model is downloaded. Cloud AI runs on provider servers: more raw power and bigger models, but every prompt leaves your machine, usage usually costs money, and the provider sets the rules and rate limits. Most people end up wanting both, which is why Sigma lets you switch between local and cloud models anytime, per task.

Do I need a powerful computer to run local AI?

Not for smaller models: modern laptops, including Apple Silicon Macs, run compact local LLMs comfortably, and even mid-range hardware handles chat and summaries well. Larger models need more RAM and benefit from a dedicated GPU, but they're optional: Sigma lets you pick a model that fits your hardware, and you can always switch to a cloud model for the heaviest tasks. If your machine can run a browser smoothly, it can run local AI.

A local LLM is a large language model that runs entirely on your own hardware instead of a provider's data center. The model file is stored on your device, and all inference (the actual “thinking”) happens on your CPU or GPU. In Sigma Browser, a local LLM powers AI Chat, page summaries, and the browser agent, so you get modern AI features while every prompt, page, and file stays on your machine. You can download a ready-to-use model right in the browser or connect one you already run.

Is local AI safe and private?

Local AI is one of the most private ways to use AI, because nothing you type is transmitted to external servers: there is simply no server involved. In Sigma, prompts, page content, and documents processed by a local model never leave your device, are not logged, and are not used for training. The browser adds another layer on top: open-source code, end-to-end encrypted sync, and prompt injection defence. For sensitive topics like health, finance, and legal, local AI is the safer default.

Can I use local AI on my phone?

Yes, within the limits of mobile hardware. Sigma Browser is available for iOS and Android, and compact local models run comfortably on modern phones, handling chat, summaries, and drafting. Larger models are still better suited to laptops and desktops with more RAM, which is why Sigma lets you pick a model that matches your device, or switch to a cloud model on the phone when you need extra power.

What can you do with local AI in a browser?

Everything you'd expect from built-in AI, minus the cloud: chat with a local AI assistant in any tab, summarize long articles, draft and rewrite text, translate, review documents, and extract key details from files. Sigma's browser agent can also run on a local model to automate web tasks like filling forms, comparing options, and collecting information, while everything is processed on-device. And because a local LLM works offline, all of this keeps working on a plane or with Wi-Fi turned off.

Is local AI open source?

Many of the best local AI models are open source or openly licensed, which is a big part of the appeal: you can see what you run, and nobody can take it away or change the terms. Sigma fits that philosophy: the browser's code is open, local models run at no cost, and you're never locked into a single provider. Download an open model right in the browser, or connect your own via API key.

Does local AI work offline?

Yes, and that's one of its biggest advantages. Because the model lives on your device, local AI keeps working with no internet connection at all: ask questions, summarize saved pages, draft and rewrite text mid-flight or off the grid. In Sigma, offline mode covers AI Chat and writing tools with your downloaded model; features that inherently need the web, like live search, loading new pages, and cloud models, resume when you're back online.

Local AI in Your Browser

Run local AI models and LLMs right in Sigma Browser: private, offline-capable, and free.

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What Is Local AI?

Local AI means running AI models directly on your device instead of in the cloud. Your prompts are processed by a local LLM on your machine, and nothing is sent to external servers. Sigma builds local AI into the browser, so there's no separate app or complex setup: download a model once, and it works in every tab.

Run LLMs locally in any tab

Your data never leaves your device

Works offline, no connection needed

Free, no API fees or subscriptions

Local AI models on-device in Sigma Browser

Why Use Local AI in Sigma Browser

Cloud AI sends every prompt to someone else's servers. Local AI keeps everything on your machine, fully under your control. Here's why that matters.

Total privacy

A self-hosted AI right in your browser: prompts, pages, and files are processed on-device, so everything you type stays strictly between you and your machine.

Works offline

Turn off Wi-Fi and keep working. A local AI model answers questions, summarizes pages, and drafts text entirely on your device, wherever you are.

One-click setup

Download local AI models right in the browser or connect your own via API key. Local AI setup takes about a minute: download, click, chat.

Open source and free

Sigma's code is open, and local AI runs completely free: you own the model, your hardware does the work, and you decide the limits.

Local AI Use Cases

What people actually run on local AI models in Sigma, and everything below keeps working even with the internet off.

Private AI chats

Ask a local AI assistant about finance, legal, or health topics. Sensitive conversations stay on your device: nothing is logged or sent anywhere.

Local AI agent

Run Sigma's browser agent on a local model: automate web tasks and fill forms in Private Mode, without cloud processing.

Summarize and write offline

Summarize any page, draft replies, and rewrite text with a local LLM, even with no internet connection.

Work with sensitive files

Review documents and extract key details locally. Contracts, reports, and personal files never leave your machine.

How to Run AI Locally in Sigma

Installing Sigma Browser from a dmg file into the Applications folder

Download Sigma Browser

Get Sigma for macOS, Windows, iOS, or Android. Free, no account needed.

Get a local AI model

Download a local LLM right in the browser, or connect your own model via API key. Local AI setup takes about a minute.

Asking the AI a question in the Sigma Browser chat box

Chat, browse, automate

Use your local model in AI Chat, on any page, or with the agent, both online and offline.

Local AI vs. Cloud AI

Both have their place. Here's the honest comparison.

Comparison Parameters

Local AI in Sigma

Cloud AI

Privacy

Data stays on your device

Prompts sent to provider servers

Offline

Works without internet

Requires connection

Cost

Free, no API fees

Subscriptions and usage fees

Speed

No network latency

Depends on connection and load

Limits

Your rules, your models

Provider rules and rate limits

In Sigma you don't have to choose: switch between local AI models and cloud models anytime. Run everyday and sensitive tasks on a local LLM, and call a cloud model when you need maximum reasoning power.

Download Sigma Browser

Download for macOS

Download for Windows

Get on App Store

Join Android waitlist

Other platforms

Also available on Windows, iOS and Android. Linux version coming soon!

Questions & Answers

If you have any questions,
reach out to us on X at @Sigma_Browser

Local AI in Your Browser

What Is Local AI?