What Capacities is
AlternativeTo files Capacities under Note-taking, Todo List Manager. It is recorded as Freemium, Proprietary, from Germany, EU. It ships on Mac, Windows, Online, Android, iPhone, Android Tablet, Linux, iPad. The topics its entry raises are linked notes.
That is our reading of the record. For AlternativeTo's own wording, see its page for Capacities — the facts above were read on 2026-08-16.
| Price | Freemium |
|---|---|
| Licence | Proprietary |
| Category | Note-taking, Todo List Manager |
| Origin | Germany, EU |
| Platforms | Mac, Windows, Online, Android, iPhone, Android Tablet, Linux, iPad |
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.
Side by side
| Side by side | SumizAI | Capacities |
|---|---|---|
| Price | $1/month, one plan, 7-day trial without a card | Freemium |
| Licence | Proprietary | Proprietary |
| Platforms | macOS, Windows, iOS, Android | Mac, Windows, Online, Android, iPhone, Android Tablet, Linux, iPad |
| Category | Note-taking — AI chat into Markdown | Note-taking, Todo List Manager |
| Where notes live | Standard .md files in a folder you choose | AlternativeTo does not say |
| AI model | Seven providers, always on your own API key | Its description does not mention AI |
| Origin | Poland, EU | Germany, EU |
Where they differ
- AlternativeTo's description of Capacities 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.
- Capacities is freemium: there is a free tier and a paid one, and the line between them is the thing to read before committing. SumizAI has one plan at a dollar a month, so there is no feature held back for a higher tier — and an unpaid account still opens and exports every vault it already has.
- AlternativeTo's description of Capacities does not mention Markdown, so check what format your notes end up in before you fill it up. SumizAI writes standard
.mdfiles to a folder you picked, and an unpaid account can still export all of them. - Capacities is described in terms of linking notes together. SumizAI links them too, but deliberately without a syntax of its own: a link is an ordinary Markdown link,
[Title](file-name.md), and the model may only point at a file that actually exists. There are no wiki-style[[…]]links to lose on export. - Both are run from the EU: SumizAI's operator is registered in Poland and the servers are in Germany.
Which one to pick
Reasons to pick Capacities
- you need it to run in a browser
Reasons to pick SumizAI
- the notes you want already exist inside conversations with an AI model
- you want the filing — title, chapter, duplicate check — to happen without you
- you want the result as plain
.mdfiles in a folder you picked - you would rather pay your AI provider directly than have a note app resell the model
Facts about Capacities: AlternativeTo, read 2026-08-16. SumizAI is not affiliated with Capacities, and the name is used only to identify the product being compared.
Taken from the AlternativeTo lists: Obsidian.