26 Sep 2026 · 8 min readLLMs

Offline LLMs: Running AI on Your Own Machine

Running a language model on your own machine is now genuinely practical — no key, no subscription, no data leaving the device. The catch is hardware. This guide covers what local models are actually better at than cloud ones, roughly what each model size needs in RAM, and the situations where local is the wrong answer.

What you actually gain

  • Privacy, genuinely. Nothing leaves the machine — which matters for client data, medical notes, anything under an NDA, and anything you simply don't want logged.
  • No cost, no rate limit, no quota. Use it as much as you like.
  • Works with no connection. Airplane mode, a train, a field site, a secure facility.
  • Offline-capable tools built on top of it — transcription, translation, summarisation of your own files.
  • Predictable latency, in the sense that it never queues behind a busy server.

What your hardware can handle

Model size in parameters, and the quantisation used to shrink it, determine what fits. The number that actually matters is memory — system RAM if you're loading from disk, or VRAM if you have a GPU.

  • 1–3B parameters: 8GB RAM is comfortable. Fast on CPU. Fine for classification, extraction, short rewrites, simple questions.
  • 7–8B: 16GB RAM, or any modern GPU with 8GB+ VRAM. This is the sweet spot for general quality.
  • 13–14B: 32GB RAM, or 12–16GB VRAM. Noticeably better reasoning and longer context.
  • 30B+: 64GB RAM or a serious GPU. Diminishing returns per GB, and it will be slow on CPU.
  • Quantisation (running the model at reduced precision) roughly halves the memory needed with a modest quality cost — 4-bit is the common default for a reason.
💡 Pro Tip: Most laptops today can run a 7–8B model at 4-bit comfortably. The bottleneck on a PC without a dedicated GPU is memory bandwidth, so expect tokens per second in the teens rather than the dozens.

How to actually run one

You do not need to install Python, learn a framework, or write any code. Pick a desktop application, download a model, and start chatting.

the shape of it
1. install a local runner (a desktop app, not a library)
2. download a model file in GGUF format, sized to your RAM
3. run it, and use it exactly like any other chat window

For developers, the same models are served over a local
API and anything that speaks that API works unchanged.

Once it's running, treat it like any other model: the prompting advice in the LLMs guide applies identically, and the failure modes are the same ones.

The honest trade-offs

  • Weaker than the best cloud models, especially on hard reasoning, long context and anything current. A 2024-era small local model will not match a frontier model.
  • No current information, and no browsing. It knows only what it was trained on, frozen at download time.
  • Slower. On a CPU, a long answer can take minutes.
  • You own the hardware cost, the disk space (tens of gigabytes) and the setup time.
  • Model choice is on you — a bad small model is much worse than a good large one, and the download is long.
⚠️ Note: Local is not automatically private. If you install something that phones home, or a web UI that proxies your prompts, the privacy benefit is gone. Check what the app actually does before you paste anything sensitive.

When local is the right answer

  • Anything confidential: client material, health notes, source code under NDA, unreleased work.
  • High-volume, repetitive work where a per-token bill adds up.
  • Environments with poor or no connectivity, or where cloud services are not permitted.
  • A base layer for your own tools — local transcription, tagging, and search over your own files.
  • When you simply want an experiment you fully control, with no account and no telemetry.

For general research, long documents and current events, a cloud model with search is still better. The two are complements: local for the private and repetitive, cloud for the hard and current.

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