SumizAI vs Altretta

What Altretta is

AlternativeTo files Altretta under Note-taking, Team Collaboration. It is recorded as Freemium, Proprietary, from Estonia, EU. It ships on Mac, Windows, Linux, Online. The topics its entry raises are encryption, collaboration, plugins and code.

That is our reading of the record. For AlternativeTo's own wording, see its page for Altretta — the facts above were read on 2026-08-16.

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

Where they differ

• Both mention AI. The difference is whose key it runs on: SumizAI never resells inference — you connect one of seven providers (Anthropic, OpenAI, Gemini, Groq, OpenRouter, a local Ollama or your own server) with your own API key and pay that provider directly. Check what Altretta does with the model bill before comparing prices.
• Altretta 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 Altretta 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.
• Altretta is described as something more than one person uses at once. SumizAI is not: there are no shared vaults, no comments, no permissions and no sync between devices. If the work is a team's, that is a reason to pick Altretta over SumizAI.
• Altretta advertises encryption. SumizAI answers the same worry a different way: on the desktop the notes never leave your disk, and the material a question sends to the model is capped at the table of contents plus at most five notes — and the app shows you which five it used.
• Altretta is extensible through plugins. SumizAI is not, and that is a genuine trade: you cannot bend it into something else, but there is also no plugin to keep working after the next release. What it does instead is fixed and small — a chat, a filing rule and a folder of Markdown.
• AlternativeTo lists no mobile version of Altretta. SumizAI runs on macOS, Windows, iOS and Android.

Which one to pick