Offline AI chat on iPhone
Short answer: yes — an AI chat can run entirely on an iPhone, with no internet. On iOS 26 with Apple Intelligence (iPhone 15 Pro and later), apps such as privateSLM and Locally AI answer with Apple's own on-device model, so there is nothing to download. On any other iPhone, an app like privateSLM, PocketPal AI or Private LLM downloads an open model once — under a gigabyte to a few gigabytes — and then works in airplane mode.
ChatGPT, Gemini and Claude are different: their apps send each message to the company's servers, so they stop working without a connection. That is also why the apps below are the private option — a model that runs on the phone has nowhere to send your words.
How to chat with AI offline on iPhone
- Install an on-device AI app — privateSLM is free, with no account (App Store).
- On an iPhone with Apple Intelligence on iOS 26, start typing: the system model is already on the phone. On any other iPhone, pick a free model once — from 0.7 GB (LFM2.5 1.2B) to 2.5 GB (Phi-4 Mini) — while you still have Wi-Fi.
- Turn on airplane mode and ask. Chat, documents and voice keep working.
Which model fits your phone depends on its memory; every model in the privateSLM catalog states the RAM it needs.
The offline AI chat apps for iPhone
| privateSLM | Locally AI | PocketPal AI | Private LLM | Enclave | |
|---|---|---|---|---|---|
| Price (US) | Free; expert packs $4.99, all $9.99, once | Free | Free | $4.99 once | Free on-device |
| Works with nothing to download (Apple's model) | Yes, on iOS 26 with Apple Intelligence | Yes, on iOS 26 with Apple Intelligence | No | No | Not mentioned |
| Documents offline | PDF, Office, Pages, scans | CSV, text, code | Not advertised | No | PDF, text, images |
| Voice | In and out | Local voice mode | Spoken replies | Not advertised | In and out |
| Minimum iOS | 17 | 18.1 | 15.1 | 17 (A12 or later) | 27 |
| Account | None | None | None to chat | None | None for local models |
We make privateSLM; the other columns are from each app's own listing, site or FAQ, read on October 21, 2026. For longer comparisons see Private LLM alternatives, Private LLM vs privateSLM and PocketPal AI vs privateSLM.
What an offline model can and cannot do
A small model on a phone is good at rewriting, summarising, explaining and answering from a document you give it. It knows less of the world than a cloud model and has no web search, so check facts it states from memory. Long answers slow down as the phone warms up — we measured that in 37.58 tokens a second lasts about four seconds.
FAQ
Can I use AI on my iPhone without internet?
Yes. Apps that run the model on the phone — privateSLM, Locally AI, PocketPal AI, Private LLM and others — work in airplane mode. On iOS 26 with Apple Intelligence, privateSLM and Locally AI use Apple's built-in model, so there is nothing to download first.
Does ChatGPT work offline?
No. The ChatGPT app sends each message to OpenAI's servers, so it needs a connection. An on-device app such as privateSLM runs the model on the iPhone instead.
What is the best free offline AI app for iPhone?
privateSLM and Locally AI are free and use Apple's on-device model where Apple Intelligence is available; privateSLM also reads PDF and Office documents offline. PocketPal AI is free and open source for running any GGUF model.
How much storage does an offline AI model need?
With Apple Intelligence, none — the model is part of iOS. Otherwise privateSLM's free models are 0.7 to 2.5 GB, downloaded once.
Is offline AI private?
When the model runs on the phone, your messages are not sent anywhere to be answered. privateSLM has no account, no server and no analytics; it uses the internet only to download a model.