Two of the AI chat apps on Android do not run their own models at all, and one of them publishes the list. DuckDuckGo names them outright: Duck.ai is described in its help pages as private conversations with third party AI chat models, and the free ones include Anthropic's Claude 4.5 Haiku, Mistral AI's Mistral Small 4, OpenAI's GPT-5.4 nano and mini, plus gpt-oss-120b and Gemma 4 31B. Microsoft's Play listing says Copilot works with the latest OpenAI and Microsoft AI models. The rest run their maker's own models, so the model is not always what separates them. What it does change is checkable: the account, the free ceiling, and what the vendor does with your conversations.
Model quality is what everyone argues about and what nobody reading a store page can settle. What is left is four things a vendor has written down.
Google puts that last one plainly in the Gemini Apps Privacy Notice: human reviewers, including trained reviewers from its service providers, review some of the data it collects, and it asks you not to enter confidential information you would not want a reviewer to see. That is the baseline for every cloud assistant here.
Google answers it in the Gemini Apps Privacy Hub. Used while signed out, Gemini Apps process data such as your IP address and browser type under the general Google Privacy Policy, that data is not associated with your Google account, and the Gemini Apps Privacy Notice does not apply.
Microsoft frames it as what you gain: signing in, its getting started page says, gives you chat history, more image creation, longer conversations and longer usage of voice. Its privacy FAQ lists users not signed into Copilot among categories it does not train on.
DuckDuckGo goes furthest. Across its Duck.ai help pages an account appears only for the paid subscription and the optional Sync and Backup. Chats save locally by default, and the daily limit is enforced by a method the company calls completely anonymous, resting on its line that it never logs IP addresses to disk.
None of that promises anything about the build on your phone; find out at first launch, before you type anything worth keeping.
One vendor states its free tier plainly: DuckDuckGo says Duck.ai is free to use, but there is a daily limit on usage. Paying adds models and raises the ceiling: GPT-5.4 and Claude Sonnet 4.6 on Plus, and on Pro also Claude Opus 4.8 and twice the Plus limits.
The others publish no number. Google's listing pins one feature to a tier: cinematic video with Gemini Omni is for Google AI Plus, Pro, Ultra and Workspace users. Anthropic's invites you to try Claude for free; OpenAI's and DeepSeek's say only that their apps are free. So do not plan around a message count you read somewhere, and for tiers on one app see using Gemini on Android.
Inputs differ, in the vendors' own words: Gemini Live shares your screen or camera, ChatGPT lists Advanced Voice Mode and photo upload, Claude takes any photo, PDF or screenshot. OpenAI's listing also describes screen share with Accessibility Services, in limited availability, answering questions about screen details without screenshot uploads. An Accessibility service can read everything on screen and act for you, so grant it deliberately, and checking what an app can access explains why it attracts abuse. You may need no voice mode at all: Android's keyboard already dictates into any text field, as our voice to text notes roundup explains.
Plenty of listings use the word private; few keep the work on the phone. PocketPal AI, from LLM Ventures, is the clearest case on Play: it says it runs large language models directly on your phone, with no servers and no data leaving the device.
The word private on a listing does not tell you where the work happens. This one is direct about the cost: 6GB or more of RAM for smaller models, 8GB or more for larger ones, older or budget devices will not cope, and, in as many words, this is not ChatGPT.
Its Data safety card is a lesson in reading one. The summary says personal info may be shared with third parties, which looks like a flat contradiction. Tap See details and the whole entry is one line: an email address, marked Optional, for account management. A summary names a category, not a quantity.
It is the trade offline translation made years ago: the text never leaves the phone, and the output sits a step below the online version, as our translator apps guide spells out.
On a Play listing, only the row between the developer name and the star rating belongs to that app. Read on 4 August 2026: ChatGPT by OpenAI, with Contains ads and In-app purchases; Microsoft Copilot by Microsoft Corporation, the same two; Google Gemini by Google LLC, neither; Claude by Anthropic PBC, In-app purchases only; DeepSeek by DeepSeek and PocketPal AI by LLM Ventures, neither.
Be strict about where you read them: the same words appear elsewhere on the page, in the carousel of similar apps and in Google's own site furniture. A normal result is not alarming, since In-app purchases on a free assistant just means a paid tier exists.
The other kind of assistant arrives without being installed: turning off Meta AI in WhatsApp is about partial controls rather than a switch. For the browser that carries Duck.ai, our Android browser roundup covers DuckDuckGo itself.
Google. With Keep Activity on, chats are saved and used, in Google's wording, to provide, develop and improve its services, including training generative AI models, auto deleting after 18 months. Off, future chats stay out of training unless you send feedback, but are still stored 72 hours. Chats already seen by service provider reviewers are disconnected from your account, kept three years, and not removed when you delete your activity.
Microsoft. Conversation activity is stored 18 months by default, and except for certain categories of user, or those who opted out, Microsoft uses it for AI training. In the mobile app: the menu, your profile icon, Account, Privacy, then turn off Training on conversation activity and Training on voice conversations. Opting out will not exclude those conversations from other general product or system improvements, nor from advertising, digital safety, security and compliance purposes.
Anthropic. On mobile: your name, Settings, Privacy, then Help Improve our AI models. Turning it off stops future training use, and Anthropic states the limit in the same breath: your data stays in training already started and in models already trained. Allowed chats may be kept de-identified for five years.
DuckDuckGo. By default Duck.ai does not record or store your chats, and conversations are not used to train models by DuckDuckGo or the underlying providers. The exceptions are published: feedback you share, prompt caching held up to an hour and never written to disk, Anthropic chats retained where law requires or to combat malicious use, and uploads scanned for child sexual abuse material.
DeepSeek and OpenAI. DeepSeek's privacy policy, updated 10 February 2026, says it collects, processes and stores personal data in the People's Republic of China, and lists opting out of training among rights that may be available where you live, exercised by email rather than a toggle. It also says a deleted account cannot be reactivated or its content retrieved. OpenAI states its position at the address printed in the ChatGPT listing.
Every one of those settings governs what happens next, not what has already gone. Find the switch on the day you install the app.
Several share them. DuckDuckGo's help pages describe Duck.ai as private conversations with third party AI chat models and name the free ones, including Anthropic's Claude 4.5 Haiku, Mistral Small 4 and OpenAI's GPT-5.4 mini. Microsoft's Play listing says Copilot works with the latest OpenAI and Microsoft models.
Some vendors document it. Google's Gemini Apps Privacy Hub covers signed out use and says that data is not associated with your Google account, and Microsoft's privacy FAQ lists users not signed into Copilot among categories it does not train on. Neither guarantees a given app will skip its sign in screen, so check at first launch.
In the Microsoft Copilot mobile app, open the menu, select your profile icon, then Account, Privacy, and turn off Training on conversation activity and Training on voice conversations. In Claude on mobile: your name, Settings, Privacy, then Help Improve our AI models. For Gemini the equivalent switch is Keep Activity, which has to be turned off. All three affect future chats only.
PocketPal AI is the clearest example on Google Play. Its listing says it runs large language models directly on the phone with no servers and no internet, and needs 6GB or more of RAM for smaller models. An app that calls itself private is not necessarily doing the work on the phone, so look for a listing that says so outright.
It is a developer declaration, not a Google audit, and the summary line is only a category. PocketPal AI's card summarises as personal info shared with third parties, while See details shows one optional email address for account management.