I refused to choose between private and capable.
Every AI tool I used asked me to trust a company with my most private thoughts — my business ideas, my personal worries, my family conversations. I wanted AI that was genuinely mine: on my device, and not readable, sellable or deletable by someone else’s policy change.
So I tried the private route — running AI locally. Every local-AI app I found was a project in itself: fiddly to set up, sluggish on an everyday laptop, and bare-bones even when it ran — none of the things that make modern AI genuinely useful.
I refused to choose between private and capable. So I built hYYa ai to do both.
Same app, same memories, your choice. We built this for everyone — the curious kid, the busy professional, the grandmother asking about her medication, the developer shipping at midnight. One app. Every level. Yours.”
The hYYa Apps Team
Everyone else makes you pick a side
Cloud assistants are capable, and every word you type is processed on someone else’s machine. Local-model runners keep everything on yours — and hand you the setup, the model-picking and the missing features along with it. Both are one-engine products. hYYa ai is built the other way round — it carries both engines, and each one covers what the other cannot.
hYYa ai
Two engines, one app. hYYa Vault answers on your device — free forever, no account, no connection. hYYa Cloud answers from frontier models when the work outgrows your machine. One switch, one conversation.
hYYa Vault
The on-device engine. Your prompts, your replies and your history stay on your machine — no account, no connection, free forever. On its own, the ceiling is whatever your own hardware can carry.
hYYa Cloud
The online engine. Frontier models, live web research and reasoning across a whole document library — no ceiling from your own hardware. On its own, it needs a connection, and the work is processed on a server.
| What differs | Cloud assistants | Local-LLM apps | hYYa ai |
|---|---|---|---|
| Engines in the app | One | One | Two |
| Answers with no connection | No | Yes | Yes — hYYa Vault |
| Frontier models | Yes | No | Yes — hYYa Cloud |
| Your own tools, the live web and your connected apps | Yes — on their servers | Rarely — most are a chat box | Tools on your device; the web and your apps at your opt-in |
| Your own hardware sets the ceiling | No | Yes | Only on hYYa Vault |
| Where your words are processed | Someone else’s servers | Your own device | Your choice, question by question |
| Switch engine mid-conversation | No | No | Yes |
“I refused to choose between private and capable.”
— the hYYa Apps team
The market sorts into those two boxes. hYYa ai is built to be neither — it is both, and the switch is yours.
Two engines, one app
You are not choosing a product at signup. Both engines live in the same app and share the same conversations and history, and you move between them between one question and the next. hYYa Vault answers on your device. hYYa Cloud answers from frontier models.
hYYa Vault
Private & On-DeviceThe on-device engine, in full.
- AI runs on your device. Your prompts, your replies and your history stay there. Nothing you type, store or open reaches a server unless you turn on an online feature — and the first time you do, hYYa tells you exactly what will leave and where it goes, then asks
- Works without Wi-Fi or mobile data; no account required
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Web search inside a DataLens lens
only your typed question leaves the device. hYYa Cloud runs the search and returns the results; the on-device model reasons over them. In ordinary chat, switching Web Search on hands the whole question to hYYa Cloud, and Cloud answers it
- Free forever — private AI shouldn’t cost a subscription
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Chat with models that run on your own device
no setup project: hYYa reads your device and recommends one model that fits, you tap once to download it, and nothing downloads on its own
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DataLens
ask your own PDFs, Word, Excel, PowerPoint and scans. Every answer points to the passage it came from, and scanned or part-scanned pages are read on your device too
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Studio
Excel workbooks with working formulas across several sheets, Word reports with a cover page and contents, PowerPoint with charts you can still edit, and interactive dashboards that stand on their own
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Quantity Surveyor
take off construction drawings to Excel: DXF gives a full per-service take-off, vector PDF gives whole-drawing totals measured from the drawing’s own geometry at the scale you set
- Turn any answer into a PDF, Word, Excel, PowerPoint or Markdown file
- Digitize invoices, schedules and contracts into verified tables
- Memory, a history you can search, and your own tools connected — each one asks before it runs
hYYa Cloud
Frontier Cloud AIThe online engine, in full.
- Frontier models from multiple labs — Claude Opus, Claude Fable and Grok, not locked to one provider (On-Demand and up) — plus advanced models like Gemini
- Web search with citations, document chat, connected apps, image & voice
- Conversations never used to train models or sold — your data is yours
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Everything hYYa Vault does
DataLens, Studio, Quantity Surveyor, file generation and Digitize are on both hYYa Cloud plans
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DataLens at library scale
Both paid plans read your whole document set in one go rather than in pieces, scanned and image-only PDFs included
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Quantity Surveyor reads binary AutoCAD .dwg
which the on-device engine cannot — take-off is on every plan
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Studio branded exports
on every plan — Word, PowerPoint, Excel, and an interactive dashboard you can publish at a link and switch off again
- Create Document from chat — Word, Excel, PowerPoint or Markdown, on request
- Digitize invoices, POs and forms into an exact Excel workbook, checked against the document’s own total
- Contract-review depth applied automatically inside DataLens — no separate tool
- Image generation and editing — attach a photo and restyle it, or combine up to six
- Real-time voice with Live Translate across 14 languages
- Opt-in Memory · Connections (8 apps) and Agents
- Bring your own API key on Cloud Ultra · credit packs on Cloud On-Demand, paid for once and never expiring · export your whole chat library to a single file
Two doors to hYYa Cloud
They differ by how you pay, not by what you get.
A one-off credit pack. You buy a balance, nothing renews and there is nothing to cancel. The credits stay on your account with no time limit, and unspent credits are refundable within 14 days.
The monthly subscription, with the largest renewing allowance and advanced models that cost no credits. The allowance refreshes each month and does not carry over; credits you buy are a separate balance the reset never touches.
Otherwise the two carry the same toolkit — Bring Your Own Key is the only thing Cloud Ultra has that Cloud On-Demand does not. There is no free hYYa Cloud tier and no trial. Current prices are on hyya.ai.
The toolkit doesn’t change when the engine does
hYYa Vault runs much of this toolkit fully on-device, free and without an account — DataLens, Studio, Quantity Surveyor, file generation and Digitize all work offline. Voice, Live Translate and image generation are hYYa Cloud only, and hYYa Vault has no microphone at all. The online extras work the other way round: Web Search, your Connections and your own API key are hYYa Vault’s to switch on — off by default, each needing a signed-in hYYa Cloud account, and each telling you what will leave before it does. Your own MCP tool servers are the exception that needs nothing at all: they run on the device, offline and with no account. Web Search in chat hands the whole question to hYYa Cloud even from the on-device engine; inside a DataLens lens only your typed question leaves and the on-device model reasons over the results. hYYa Cloud is about scale and reach: a whole tender package rather than one drawing, reasoning across an entire library at once rather than one document, plus frontier models and live web search. Everything that follows is on both hYYa Cloud plans, counted against your allowance — the frontier models and whole-library DataLens included. The one exception is Bring Your Own Key, which is Cloud Ultra only.
Both engines
Smart Memory
Opt-in per user, off for total privacy — hYYa remembers what you choose.
Both engines
DataLens
Chat with PDFs, contracts and reports on every plan. On either paid plan, read a whole library at once and share it with a team of up to 10.
hYYa Vault
Your own tools (MCP)
Connect your own MCP tool servers and run them on your device — offline, with no account, and every call asks before it runs.
hYYa Cloud · Vault opt-in
Web Search
Off by default, switchable on while the on-device engine is selected. hYYa Cloud runs the search — in chat it answers the whole question; in a DataLens lens only your typed question leaves and the on-device model reasons over the results. Needs a signed-in hYYa Cloud account.
hYYa Cloud · Vault opt-in
Connections
Gmail, Calendar, Outlook and Notion, read-only — off by default and switchable on from the on-device engine. Needs a signed-in hYYa Cloud account.
Cloud Ultra · Vault opt-in
BYOK
Bring your own API key — your models, your quota, your billing. Switchable on from the on-device engine, and Cloud Ultra only.
hYYa Cloud
Agents
Daily app briefs on autopilot, built on your Connections.
hYYa Cloud
Image & Voice + Live Translate
Generate images, speak hands-free, interpret across 14 languages in real time.
Frequently Asked Questions
How is hYYa ai different from a cloud AI assistant, or from a local-LLM app?
Those are one-engine products. A cloud assistant is capable, and everything you ask is processed on someone else’s servers, with no offline mode. A local-LLM app keeps everything on your machine, and stops at whatever your hardware can carry. hYYa ai carries both engines in one app: hYYa Vault answers on your device, free and without an account, and hYYa Cloud answers from frontier models when a job outgrows your machine. You switch between them between one question and the next, and the conversation carries over. The free app carries both engines on Mac, iPhone, iPad and Android; hyya.ai in a browser is hYYa Cloud.
How is hYYa Vault different from other local-LLM apps?
Most local-LLM apps hand you a chat box, and leave the setup, the model-picking and every missing feature to you. hYYa Vault reads your device and recommends one model that fits, nothing downloads on its own, and the toolkit comes with it: DataLens over your own PDFs, Word, Excel, PowerPoint and scans, with a citation to the passage each answer came from; Studio exports; construction take-off from DXF and vector PDF; file generation and Digitize. All of that runs on your device, free, with no account and no connection. It also connects your own MCP tool servers on the device, and every call asks before it runs. Then there is the part a chat box cannot do: at your explicit opt-in hYYa Vault reaches further — web search, your connected apps read-only, and your own API key on Cloud Ultra — each off by default, each telling you what will leave before it does. Web search in chat is answered by hYYa Cloud; inside a DataLens lens only your typed question leaves and the on-device model reasons over the results. Voice and image generation are hYYa Cloud only, and hYYa Vault has no microphone at all.
Where do I use hYYa ai?
hYYa ai is live on the web at hyya.ai, which works in any browser with nothing to download. There is also a free app, on the App Store for Mac, iPhone and iPad and on Google Play for Android — one download that carries both engines: hYYa Vault runs entirely on your device with no account and no internet, so it answers offline on an iPhone, an iPad or an Android phone exactly as it does on a Mac, and hYYa Cloud adds the frontier models and live web research — you switch between them whenever you like. The Mac needs Apple silicon running macOS 26 or later and will not run on an Intel Mac; iPhone and iPad need iOS or iPadOS 26 or later; Android needs Android 8.0 or later on a 64-bit device. Vault needs no account at all; signing in is only for hYYa Cloud, and one account then covers the web and every device.
What’s the difference between hyya.com and hyya.ai?
hyya.com is the hYYa Apps studio site — the home of all hYYa apps, our story, and this showcase. hyya.ai is the live product itself: sign in, choose your plan, and start using hYYa ai. Think of hyya.com as the portfolio and hyya.ai as the front door to the app.
How does hYYa ai relate to the other hYYa apps?
hYYa ai is the flagship app from hYYa Apps, the studio that also builds hYYa Prayer Pal and hYYa Subscriptions Tracker. All three apps share the same design philosophy — private by default, beautifully built — but serve different daily needs. You can find every hYYa app at hyya.com.
Is hYYa Vault really offline?
Yes. hYYa Vault uses AI models that run entirely on your device, and out of the box nothing you type, store or open is sent to any server — not your prompts, not your responses, not your conversations. The features that can reach the internet are off until you switch them on — web search, connected apps, your own API keys and cloud-scale DataLens. Each is off by default, each needs you to sign in, and each tells you what will leave your device before it does — Web Search sends your message text for that turn, never your documents, files or chat history. It works without a Wi-Fi or mobile connection. No account is required, and it is free forever. Offline does not mean cut down: DataLens answers questions about your own PDFs, Word, Excel, PowerPoint and scanned documents and points to the passage each answer came from, reading scanned pages as well; Studio builds Excel workbooks with working formulas, Word reports, PowerPoint with charts you can still edit, and interactive dashboards; Quantity Surveyor takes off construction drawings to Excel from DXF and vector PDF; and any answer can become a PDF, Word, Excel, PowerPoint or Markdown file. Voice and image generation are hYYa Cloud only.
How much does hYYa ai cost?
The hYYa ai app is a free download and carries both engines, so hYYa Vault runs on your own device at no cost, forever — no account, no connection, nothing to pay. hYYa Cloud is the paid half, and it has exactly two doors: a one-off credit pack, which buys a balance and never renews, or a Cloud Ultra subscription. There is no free hYYa Cloud tier and no trial. Current prices are on hyya.ai, which is where you buy.
What can hYYa Cloud do?
Everything hYYa Vault does, plus more. DataLens answers questions about your own PDFs, Word, Excel, PowerPoint and scanned documents and points to the passage each answer came from, and on either paid plan it reads your whole library at once. Studio builds branded Word, PowerPoint and Excel exports, and an interactive dashboard that stands on its own — publish it at a link, and switch it off whenever you like. Quantity Surveyor takes off construction drawings to Excel, and hYYa Cloud is the engine that reads binary AutoCAD .dwg. It also adds Create Document, Digitize, contract-review depth inside DataLens, image generation and editing, real-time voice with Live Translate across 14 languages, web search with citations, opt-in memory, Connections to 8 apps and Agents.
What is actually free?
The app itself, and the whole on-device engine with it. hYYa Vault runs entirely on your own machine — chat, DataLens over your own documents, Studio exports, construction take-off and file generation — with no account, no connection and no cost, for as long as you use it. What is not free is hYYa Cloud: there is no free Cloud tier and no trial, so reaching the frontier models and the online features means buying a credit pack or subscribing.
How do the hYYa Cloud tiers differ?
By how you pay, not by what you get. Cloud On-Demand is a one-off credit pack: you buy a balance, nothing renews, there is nothing to cancel, the credits you buy stay on your account with no time limit, and unspent credits are refundable within 14 days. Cloud Ultra is the monthly subscription, with the largest renewing allowance and advanced models that cost no credits. Your monthly allowance refreshes each month and does not carry over; credits you buy are a separate balance, and the reset never touches them. Otherwise the two carry the same toolkit — Bring Your Own Key is the only thing Ultra has that On-Demand does not. Current prices are on hyya.ai.