SumizAI vs Notes (PFA)

What Notes (PFA) is

What Notes (PFA) is

Notes, also known as Privacy Friendly Notes, is an Android notes app built by the SECUSO research group at the Karlsruhe Institute of Technology in Germany. It's part of the broader Privacy Friendly Apps family — an academic project aiming to prove that everyday mobile apps can work without collecting unnecessary user data, without ads, and without the hidden tracking mechanisms common in many free apps on app stores.

Key features

The app focuses on the core function of a notebook — creating, editing, and managing text notes — without the elaborate, rarely used features that in other apps often serve as a pretext for requesting extra system permissions. No ads and no analytics trackers means the app doesn't quietly reach out to external ad servers in the background, something that can be verified since the code is fully open. Minimal required system permissions are one of the foundations of the whole Privacy Friendly Apps family — the app only asks for access truly necessary to save notes, not for your contact list, location, or microphone without clear reason. A clean, simple interface free of distractions supports focusing on the content of the notes themselves.

Who it's for

Notes (PFA) appeals to privacy-conscious Android users who don't want a simple notes app demanding access to contacts, location, or the microphone without a clear reason. Students and staff at German academic institutions, where the SECUSO project has name recognition, as well as anyone generally interested in software designed with data protection in mind from the ground up, will find a tool aligned with their priorities here.

Use cases

In practice, Notes (PFA) works as a basic notebook for everyday jotting — shopping lists, quick reminders, meeting notes — for people who deliberately avoid apps that collect data in exchange for free access. Someone working in a sector requiring extra caution around data privacy, such as healthcare or law, might choose this app precisely because of its open, auditable source code. Someone learning about digital privacy might treat Notes (PFA) as a practical example of what a simple app designed around data minimization should look like.

Pricing and business model

Notes (PFA) is entirely free and open source under the GPL-3.0 license, with no premium tier, no ads, and no user-data monetization mechanism of any kind. As an academic project, the app isn't maintained for profit, only as proof that privacy and usability don't have to be mutually exclusive.

Limitations and what to watch for

The focus on simplicity and minimalism means the app lacks advanced features found in commercial notebooks — cloud sync, sharing notes with other users, or rich text formatting. Being Android-only excludes iOS and desktop users entirely, which could be a real limitation for anyone working across multiple platforms.

AI notes with a minimalist approach

Notes (PFA) has no built-in AI model integration — which actually fits the project's philosophy centered on minimalism and privacy. Anyone wanting to keep an ai notes entry from an assistant conversation has to copy the text manually into a new note, with no automatic mechanism to capture the conversation. For many users of this app, that's a deliberate trade-off — fewer integrations with external services means fewer potential points of data leakage, even at the cost of convenience when saving ai notes.

What's worth checking before choosing

Before making Notes (PFA) your main notebook, check whether the lack of cloud sync and lack of a version for other platforms will be a problem in your daily use — the app is designed for local note storage on one device, not for multi-platform work.

Bottom line

Notes (PFA) is a modest but consistent app proving that an Android notebook can work without collecting data and without ads. Anyone who needs ai notes from AI conversations to land there automatically instead of requiring manual copying should look for a tool built around that specific workflow.

Academic context as a quality guarantee

The fact that Notes (PFA) was built within a technical university research project rather than a commercial company has concrete consequences for the user — its privacy claims aren't just marketing language, but the outcome of a research methodology the SECUSO group applies when analyzing permissions and data flow in mobile apps. The whole Privacy Friendly Apps family, Notes included, has been the subject of academic publications describing the methodology behind designing privacy-oriented apps, adding a layer of credibility beyond the developer's own claims.

A deliberately narrow scope, not a limitation

In a world of note apps racing to add more features, Notes (PFA) swims against the current, deliberately limiting its scope to the bare minimum needed to save and browse text. That design choice doesn't stem from a lack of development resources, but from the conviction that every extra feature is a potential extra system permission and extra attack surface that needs securing — the less code and fewer features there are, the easier it is to verify the app truly does only what it claims, and nothing more, including never sending any data off the device, not even an ai notes entry pasted in manually.

Trust built through verifiability

For a user without a technical background, it's hard to independently judge whether an app truly protects privacy the way its app-store description claims — which is why Notes (PFA)'s open source code matters beyond the circle of developers. Independent people and organizations working in digital security can run their own code audit and publish the results, giving the rest of the user base an indirect quality guarantee instead of relying solely on the maker's word. That transparency also covers how every single ai notes entry is stored, should someone choose to save one there manually — the entire storage mechanism is public and traceable line by line.

Comparison with SumizAI

Notes (PFA) and SumizAI share a concern for privacy, but differ in scope and medium. Notes (PFA) is a minimalist, local Android notebook with no external integrations at all. SumizAI generates ai notes directly from a conversation with an AI model — answers worth keeping land automatically as Markdown files in a vault the user owns, while keeping full control over the data. Anyone looking for an absolutely minimal, purely local phone notebook will pick Notes (PFA); anyone who wants ai notes from AI conversations to be created automatically while keeping data private will find SumizAI the better-fitting tool.

What SumizAI is

A note-taking application built around a conversation with an AI model. You ask a question, the answer streams back, and the answers worth keeping become Markdown notes — filed into a vault that is a folder on your own disk.

A vault is a directory holding base.md, a generated table of contents up to six levels deep, and a notes/ folder with one .md file per note. Before a note is written it is checked against the ones already there, so the fourth note about the same idea gets merged instead of added. Links between notes are ordinary Markdown links to files that exist.

The model is never ours: you bring your own API key to one of seven providers — Anthropic, OpenAI, Gemini, Groq, OpenRouter, a local Ollama or your own server — and pay that provider directly. A question sends the table of contents plus at most five relevant notes within a 24,000-character budget, and the app shows you which five it used.

Every answer kept this way becomes one of these ai notes, ready to search again months later without hunting back through old chats.

Side by side

Where they differ

• AlternativeTo's description of Notes (PFA) does not mention an AI model. That is the whole starting point in SumizAI: you have a conversation with a model on your own API key, and the answers worth keeping become notes without you filing them.
• Notes (PFA) is open source (GPL-3.0), and SumizAI is not. If reading the source is what decides it for you, that is a real argument for Notes (PFA). The guarantee SumizAI offers instead is structural rather than legal: the notes are Markdown files in a folder you chose, so they open in any editor whether or not the application is running.
• AlternativeTo's description of Notes (PFA) does not mention Markdown, so check what format your notes end up in before you fill it up. SumizAI writes standard .md files to a folder you picked, and an unpaid account can still export all of them.
• Both are run from the EU: SumizAI's operator is registered in Poland and the servers are in Germany.

Which one to pick