What Merlin AI is
AlternativeTo files Merlin AI under AI Writing, AI Chatbot. It is recorded as Freemium, Proprietary, from United States. It ships on Android, iPhone, Android Tablet, iPad, Google Chrome. The topics its entry raises are plugins and chat.
That is our reading of the record. For AlternativeTo's own wording, see its page for Merlin AI — the facts above were read on 2026-08-16.
| Price | Freemium |
|---|---|
| Licence | Proprietary |
| Category | AI Writing, AI Chatbot |
| Origin | United States |
| Platforms | Android, iPhone, Android Tablet, iPad, Google Chrome |
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 | Merlin AI |
|---|---|---|
| Price | $1/month, one plan, 7-day trial without a card | Freemium |
| Licence | Proprietary | Proprietary |
| Platforms | macOS, Windows, iOS, Android | Android, iPhone, Android Tablet, iPad, Google Chrome |
| Category | Note-taking — AI chat into Markdown | AI Writing, AI Chatbot |
| 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 mentions AI |
| Origin | Poland, EU | United States |
Where they differ
- Merlin AI is a place to have the conversation. SumizAI is not a chatbot — the conversation is the input, not the product. What comes out of it is a
.mdfile with a title, a place inbase.mdand a duplicate check against the notes already in the vault. If you only want to talk to a model, you do not need SumizAI. - Merlin AI 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 Merlin AI 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. - Merlin AI 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.
Which one to pick
Reasons to pick Merlin AI
- you want to extend it with plugins
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 Merlin AI: AlternativeTo, read 2026-08-16. SumizAI is not affiliated with Merlin AI, and the name is used only to identify the product being compared.
Taken from the AlternativeTo lists: ChatGPT.