SumizAI vs VT

What VT is

What VT (VT Chat) is

VT Chat is a free, open-source AI chat application putting privacy first — all conversations stay local on the user's device, while the app provides access to more than fifteen AI models, including Claude 4 Sonnet, Claude 4 Opus, O3, Gemini 2.5 Pro, and DeepSeek R1. Released under the MIT license, VT combines advanced research capabilities with full code transparency and no central server storing conversation history.

Key features

Local conversation storage means chat history never leaves the user's device, unlike most commercial chatbots that store data on the provider's servers. Access to more than fifteen AI models in one app lets users compare responses across different systems without switching between separate tools or subscriptions. Advanced research capabilities support deeper analysis of topics requiring repeated querying and synthesis of information from multiple sources. Open-source code under the MIT license lets any developer verify exactly how the app handles data and customize it to their own needs.

Who it's for

VT Chat appeals to people who value privacy over the convenience of centralized cloud services — researchers working with sensitive data, developers who want to verify the code responsible for handling their conversations, and users concerned about how large tech companies use the history of their AI conversations. People who want to compare different AI models' answers to the same question, rather than relying on one provider, will find VT a natural tool for such experiments.

Use cases

In practice, VT Chat works well for working with confidential company documents, where local conversation storage eliminates the risk of a data leak through an external server. A researcher comparing the quality of different models' answers to the same complex question can switch between Claude, Gemini, and DeepSeek in one app, without creating separate accounts. A developer auditing the security of AI tools reads VT's source code to verify exactly how the app handles API keys and user data. Someone working offline or in an environment with limited internet access appreciates that conversation history stays available locally regardless of the server connection.

Pricing and business model

VT Chat is entirely free and open source under the MIT license — there's no fee for the app itself. Actual costs come from using individual AI models, paid directly to providers (Anthropic, Google, OpenAI, DeepSeek) depending on which API keys the user uses. That model gives full control over spending — you pay only for queries actually made to specific models, with no flat subscription fee for the app itself.

Limitations and what to watch for

Having to configure API keys for individual model providers yourself means an extra technical step not present in ready-made commercial chatbots with one account and one bill. Local data storage, while good for privacy, also means no automatic syncing of conversation history across different devices without extra setup. As an open-source project, the pace of adding new models and features depends on the activity of the contributor community rather than the resources of a commercially funded company.

AI notes stored locally

VT Chat itself offers no mechanism for exporting conversations as organized, portable note files — history stays in the app's local database, accessible only from within VT itself. A user wanting to keep a fragment of a conversation as an ai notes entry in Markdown format, alongside their other notes, has to manually copy the text out of the chat window and paste it into a separate notebook. For someone building an organized collection of ai notes from conversations with different AI models tested in VT, that manual step is the only available solution, since the app has no built-in export to a file format compatible with other notebooks.

A model without a middleman

Paying providers directly, instead of through an intermediary subscription to the app itself, means no markup added by VT on top of query prices — the user pays exactly what a given model costs at the source. For people using multiple models heavily at once, that can mean real savings compared to commercial aggregators that add their own margin to every query.

Trust built through code transparency

In a world where more and more AI tools operate as a black box, VT's open code lets anyone interested check exactly what happens to entered text — whether it goes anywhere off the device, how API keys are stored, whether any hidden telemetry mechanism exists. That transparency matters especially to organizations with strict data-security requirements that want to independently verify a tool before approving it for internal use.

What's worth checking before choosing

Before installing VT, it's worth checking whether you already have access to API keys for the models you want to use, since the app itself doesn't provide access to models — it's an interface, not a compute provider. It's also worth assessing whether local data storage without automatic syncing across devices fits your way of working, especially if you use multiple computers.

Bottom line

VT Chat is a solid choice for people who value privacy and want to compare multiple AI models in one open-source app with local data storage. Anyone who wants valuable fragments of conversations to automatically become ai notes saved as portable files should consider a tool built around that kind of export.

Comparison with SumizAI

VT Chat and SumizAI share a concern for privacy and local data, but differ in their main purpose. VT is an interface for talking to multiple AI models at once, with history stored locally but no mechanism for exporting to portable notes. SumizAI focuses on exactly that step — turning valuable answers from an AI conversation into ai notes saved as Markdown files in a vault the user owns. Anyone who wants to compare multiple models in one place will reach for VT; anyone who wants the best answers to automatically land in an organized file archive will find SumizAI a tool matched to that specific goal — and the two can work side by side, each in its own role.

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

• VT 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 .md file with a title, a place in base.md and a duplicate check against the notes already in the vault. If you only want to talk to a model, you do not need SumizAI.
• VT is open source (MIT), and SumizAI is not. If reading the source is what decides it for you, that is a real argument for VT. 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 VT 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.
• VT can be self-hosted. SumizAI has nothing to host on the desktop — the vault is a folder on your machine — and if you want the model on your own hardware too, a local Ollama is one of the seven providers it speaks to.
• VT runs in the browser. SumizAI is a desktop and mobile application, and on the desktop the vault is a folder on your own disk rather than a document in someone's cloud.

Which one to pick