Brello vs ChatGPT: where your questions go

At a glance

Brello 1.0 and ChatGPT differ most in where a question is processed and who keeps a copy of it.

Where your question is processed

Brello 1.0 processes your question on the phone; ChatGPT sends it to OpenAI. That single difference shapes everything else on this page.

In Brello 1.0, the prompt goes only to the on-device runtime, Google’s LiteRT-LM, which runs one of three downloaded models on the phone’s GPU, or on its CPU when the GPU isn’t available: Brello Pro, based on Gemma 4 E4B by Google; Brello Vision, based on Gemma 4 E2B by Google; or Brello Core, based on Qwen3 1.7B by Alibaba. All three are released under Apache 2.0, and Brello isn’t affiliated with or endorsed by Google or Alibaba. Photos are copied into Brello’s private app storage and never uploaded. There is no Brello server, proxy or relay, so there are no Brello logs to keep. The one exception, web search, is covered below.

OpenAI’s privacy policy says it collects “Personal Data that you provide in the input to our Services (‘Content’), including your prompts and other content you upload, such as files, images, audio and video”.1 Its consumer data page says content “is stored on OpenAI systems and our trusted service providers’ systems in the US and around the world”, and that OpenAI may also send “select portions of content to trusted service providers” for “data annotation and safety purposes”.2

OpenAI publishes a separate version of its privacy policy for people in the European Economic Area, the United Kingdom and Switzerland. We quote the general version, updated 30 July 2026.1 For the general case of how cloud and on-device assistants differ, see on-device AI, explained.

What is stored, and for how long

Brello 1.0 keeps chats only on the phone until you delete them. ChatGPT keeps saved chats in your OpenAI account until you delete them, then removes them from OpenAI’s systems within 30 days, with exceptions.

Brello 1.0 writes chats, including any “Thought process” text, to a single file, conversations.json, in its private app storage. Android backup is turned off for the app, and its data-extraction rules exclude every storage domain from cloud backup and from device-to-device transfer, so chats are not copied to Google Drive backups or to a new phone. You delete a chat by swiping left on it, or every chat with “Delete all chats” in Settings. Nothing is synced, so if the phone is lost or reset, the chats are gone.

OpenAI says regular and archived chats “remain saved to your account until you delete them”. When you delete one, ChatGPT removes it from view immediately, and OpenAI “schedules it for permanent deletion from its systems within 30 days, unless the chat was already de-identified and disassociated from your account or OpenAI must retain it longer for security or legal obligations”.3 The privacy policy gives examples of longer retention: content or an account banned for breaking OpenAI’s usage policies, and data OpenAI is legally required to keep, such as under a subpoena.1

One legal hold is still in place. OpenAI’s post on The New York Times’ data demands, updated 22 October 2025, says its obligations under a court order to retain consumer ChatGPT content ended on 26 September 2025, and that it will “securely store limited historical April–September 2025 user data”, which “remains locked down, accessible only to a small, audited OpenAI legal and security team”.9

Is it used to train models?

Brello 1.0 can’t use your chats for training, because they never leave the phone. OpenAI may use ChatGPT conversations to train its models unless you opt out.

For its services for individuals, including ChatGPT, OpenAI says “we may use your content to train our models”. To opt out, you turn off “Improve the model for everyone” under Settings › Data controls, or select “Do not train on my content” in OpenAI’s Privacy Portal; after that, OpenAI “won’t use your new conversations to improve our models”.4 Feedback is an exception: if you rate a response with a thumbs up or down, “the entire conversation associated with that feedback may be used to train our models”, even after opting out. OpenAI also says it takes steps “to reduce the amount of personal information in training datasets”.4

People can see some content too. OpenAI says a limited number of authorised staff and trusted service providers may access user content to investigate abuse or a security incident, to provide support, to handle legal matters, or “to improve model performance (unless you have opted out)”. The same page asks: “Please do not enter sensitive information that you would not want reviewed or used.”2

Business plans work differently. OpenAI says that by default it doesn’t use inputs or outputs from ChatGPT Business, Enterprise or Edu, or from its API, to improve its models.4

Brello 1.0 has no account system, no analytics and no crash reporting, and no Brello server receives your questions. We have nothing to train on and nothing for a person to review.

Temporary Chat and memory

ChatGPT’s Temporary Chat keeps a conversation out of your history and out of training, though OpenAI may keep a copy for up to 30 days. Brello 1.0 has no temporary mode and no memory across chats.

OpenAI says “a temporary chat stays out of your chat history and is not used to improve OpenAI models while it remains temporary”. You choose before the first message whether it uses your existing memories; either way it doesn’t create or update them, and “OpenAI may keep a copy of a temporary chat for up to 30 days for safety purposes”. Saving a temporary chat turns it into a regular chat, which then follows your account’s settings.6

Memory works the other way. “When Memory is enabled, ChatGPT can remember relevant preferences and details from your chats and other available sources”, which, depending on plan and region, can include past chats, saved memories, custom instructions, files in Library and connected apps such as Gmail. Turning off “Reference chat history” schedules what was remembered from past chats for deletion within 30 days, and OpenAI “may retain logs of deleted saved memories for up to 30 days for safety and debugging purposes”.7

Brello 1.0 has neither feature. Each answer draws only on the last six messages of the current chat, clipped to fit a 4,096-token context window, so nothing carries over from one chat to the next. Every chat stays on the phone until you delete it.

Accounts and sign-in

Brello 1.0 has no accounts. ChatGPT can be used without signing in, but saved history, data export and account deletion belong to an OpenAI account.

OpenAI’s data-controls page explains how to turn off model training “when using ChatGPT without signing in”, in which case the choice is “saved in that browser”; when you are signed in, the setting “applies to your account across devices”. Signed-in Free, Go, Plus and Pro users can request a copy of their data and delete their account from settings.5 Creating an account means giving OpenAI the account information its privacy policy lists: “your name, contact information, account credentials, date of birth, payment information, and transaction history”.1

Brello 1.0 asks for none of this: there is no sign-up, and the models download from Hugging Face without an account or token.

Offline use

Brello 1.0 works offline after a one-time model download. None of the OpenAI pages we checked describes an offline mode for ChatGPT.

Brello Core is a 977 MB download, Brello Vision 2.59 GB and Brello Pro 3.66 GB, and Wi-Fi is recommended for it. After that, the assistant works fully offline; only web search, which is optional, needs a connection.

Web search: who sees the query

In both products a search provider receives a rewritten version of your question. They differ in who sends it and what travels with it.

Brello 1.0’s web search is off by default. With it off, a question that looks time-sensitive brings up a card titled “Search the web for this?” with two buttons, “Search the web” and “Answer offline”. When Brello searches, the phone sends a cleaned-up search text, sometimes with up to 10 words of the previous question added for context on a follow-up, directly to DuckDuckGo, Bing, Brave Search, Google News or Wikipedia, and then fetches up to four result pages itself. The requests carry Do Not Track and Global Privacy Control headers, and the model that reads the pages and writes the answer still runs on the phone. The search engine and the websites see a normal request, including the phone’s IP address.

OpenAI says ChatGPT search “sometimes partners with other search providers”, and when it does, it “typically rewrites your query into one or more targeted queries that it sends those providers”. ChatGPT may share a general location derived from your IP address, but OpenAI says “ChatGPT does not share the IP address itself, or any of your ChatGPT account information, with third-party search providers in order to run the search”. With Memory on, saved memories can shape the rewritten query.8

The trade-off runs both ways. Brello puts no company between you and the search engine, but the engine sees your phone’s IP address. ChatGPT keeps your IP address from its search partners, but OpenAI receives your whole question. How AI assistants handle your data explains these patterns in general terms.

What ChatGPT offers that Brello 1.0 doesn’t

ChatGPT has a much wider feature set than Brello 1.0. These are the differences OpenAI’s own pages describe.

• Memory across chats. ChatGPT can draw on past chats, saved memories, custom instructions, files and connected apps such as Gmail.7 Brello 1.0 carries only the last six messages of the current chat.
• Files, audio and video. OpenAI’s privacy policy lists files, images, audio and video among the content you can upload.1 Brello 1.0 takes text and at most one photo per message, with no files and no voice.
• History that follows your account. Saved chats stay in your account.3 Signed-in users on personal plans can export a copy of their data.5 Brello 1.0 has no sync, backup or export.
• More places to use it. ChatGPT runs on the web, iOS and Android.5 Brello 1.0 runs on Android phones and iPhone.
• Local results. ChatGPT search can use an approximate location from your IP address, or your device location if you share it, for nearby businesses, local news and weather.8 Brello 1.0 has no location permission.
• Projects and custom GPTs. Files can be kept as knowledge for a custom GPT or added to a project.3

Where Brello is weaker

Brello 1.0 is a prototype with small on-device models, and it gives up convenience to keep processing on the phone.

• Availability. Brello 1.0 (version 1.0.0, 4 October 2026) is on Google Play and the App Store.
• Smaller models. On-device models are far smaller than frontier cloud models: they can be wrong, have a knowledge cutoff and are weaker at long or complex reasoning. Brello’s system prompt asks the model to admit uncertainty, which is no guarantee.
• Short memory. A 4,096-token context window; each answer sees only the last six messages, clipped.
• Hardware demands. Android 8.0 or newer on a 64-bit ARM phone, 12 GB of RAM recommended for Brello Pro, a 977 MB to 3.66 GB download plus a speed cache of similar size, and up to a minute for a model’s first launch.
• Fewer inputs. One photo per message; no files, no voice input or output, and an English-only interface.
• No sync, backup or export. If you lose or reset the phone, the chats are gone.
• Web search depends on others. Third-party engines can take up to about 14 seconds per attempt or return nothing, and they see your IP address.

Other comparisons

We answer the same questions for four other assistants, each from its provider’s own pages.

• Brello and the Gemini app: activity storage, human review and Gemini Nano
• Brello and Claude: model training and how long Anthropic keeps chats
• Brello and Microsoft Copilot: where your questions go
• Brello and Perplexity: two ways to answer from the web

Sources, with the dates we checked them

We opened each page ourselves on 5 October 2026. Where a page shows its own date, we give it too.

Facts about Brello describe Brello 1.0, version 1.0.0 (build 1), as of 5 October 2026. Product names are trademarks of their owners; Brello isn’t affiliated with them.