How To Tell If An AI Tool Really Runs Offline

“Runs on your device” has become a marketing phrase rather than a technical one. Plenty of tools that say it still send your text somewhere, either for part of the work or for everything except a cached greeting.

If the reason you want local processing is a real obligation, a client contract, a regulated environment, an NDA, then you need to verify rather than trust the landing page. Here is how, in rough order of effort.

Pull The Network Cable And Try It

The cheapest test is the most conclusive one. Disconnect from the network entirely, airplane mode plus unplugging any dock, and then use the feature.

A genuinely local tool works. A partially local tool fails in a specific and revealing way: it will often still open, still show your history, and then either hang or produce an error the moment you ask it to actually generate something.

Do this on a fresh launch as well as a warm one. Some tools fetch a token or a configuration file at startup and behave correctly until you restart them offline.

If a tool passes this test, it is processing your text locally. Nothing else you read matters as much as this result.

Read The Claim Carefully, Because The Hedges Are Load Bearing

Vendors who are being careful write narrow claims. Vendors who are not write broad ones. The difference is visible if you read for scope rather than tone.

Compare these two sentences.

Before:

Your data is processed securely on your device and never shared.

After:

In Local mode, rewrite text is processed entirely on your device and is never sent to a server. Your account and opt-in diagnostics still use the network.

The first sounds stronger and says less. “Processed securely” is compatible with a server round trip. “Never shared” is a claim about third parties, not about transmission. The second sentence tells you which mode, which data, and what is excluded, which means you can check it.

Wrivio’s own claim is deliberately in the second shape: local text never leaves your machine, but the app is not anonymous, because there is an account and there can be opt-in diagnostics that never include your text. That distinction is the whole point. A tool claiming to be both fully local and fully accountless is usually eliding something.

Watch What The Process Actually Does

If you want more than a pass or fail, Windows gives you the tools without installing anything.

Resource Monitor, reachable from Task Manager’s Performance tab, has a Network view that lists connections per process. Run a rewrite and watch whether the application opens anything. A local generation should produce no new connections at all.

Task Manager itself tells you something too. Local inference is a sustained CPU load lasting as long as the generation. If a tool produces a result in 400 milliseconds with no CPU spike, it did not run a model on your processor.

That second signal is a useful sanity check even when you cannot inspect the network, because you cannot fake the physics. Generating a paragraph on a CPU takes measurable work.

Check Whether The Model Is Actually On Disk

A local tool has to have a model file, and those files are large. If nothing on your machine grew by a gigabyte or more when you enabled local mode, there is no local model.

Look for a .gguf file or a comparable model format in the application’s data directory. Wrivio’s local tiers are Apache 2.0 Qwen3 models: roughly 1.1GB for the 1.7B Standard tier and 2.4GB for the 4B Best tier. Those numbers are the honest cost of on-device processing, and any tool offering local inference without a download of that magnitude is worth a second look.

Understanding the GGUF format helps here, because knowing what the file is makes it obvious whether one exists.

Decide What You Actually Need Before You Audit

Most people do not need every task to be local, and pretending otherwise leads to abandoning the whole idea when the local path is inconvenient.

The useful exercise is sorting your work once. Client-confidential drafts, anything under an NDA, anything with personal data in it: local. A subject line for a newsletter: it does not matter. Which tasks should stay local walks through that sorting, and what local AI on a work laptop asks of you covers the IT side.

A Wrivio Context for confidential drafting could say:

Rewrite this as a clear professional message. Do not soften commitments or deadlines. Keep every name, date, figure, and contract reference exactly as written. Do not add any detail that is not already in the text.

Press Ctrl+Shift+Space with Local selected, paste the draft, and check the diff. With the network off, you can watch the whole thing happen with no connection open.

Common Questions

What is the fastest way to check if a tool runs locally?

Turn off networking completely, restart the application, and try to generate something. A genuinely local tool works normally; a cloud tool fails at the moment of generation even if the rest of the interface still loads.

Does “on-device” always mean my text never leaves the machine?

No. Some tools run small tasks locally and send larger ones to a server, and some run everything remotely while caching results locally. Read for which mode and which data the claim covers rather than the phrase itself.

Is a tool with an account still private?

It can be. An account means the vendor knows you exist, which is different from the vendor seeing your text. The honest framing is private rather than anonymous, and any tool claiming both without explanation deserves scrutiny.

How large should a local model download be?

For a useful text model, expect at least a gigabyte and often several. A local feature that appears without any sizeable download is almost certainly not running a language model on your hardware.

Download Wrivio for Windows and run the disconnected test yourself before you trust any claim we make on this site.