Tacita

A chat that never leaves
your devices.

On-device AI on your phone. Your computer as the heavy-lift backend. Sealed end-to-end with a key only you know.

Get it on Google Play Coming soon App Store

No server. No account. No telemetry.

The pair

One key. Two devices.

A real model on the phone. Heavy lifting on the computer. Packets sealed end-to-end with the same vault key — never a server in the middle.

iOS / Android

Tacita Mobile

A real language model on your phone. Sealed by a key only you know.

Get the app

Windows / Linux

Tacita Desktop

Pair once and the phone offloads heavy generations to your computer's GPU.

Get the desktop app
How it works

Three things, no exceptions.

On your device, by design

The language model runs locally. No prompt or response ever touches a server.

Sealed with your key

Your conversations are encrypted with a password only you know. We can't recover it. That's the point.

Multiple vaults

Keep separate encrypted spaces on the same phone. Personal, work, anything else — never mixed.

Features

Built for serious
conversations.

Every feature is shaped by the same constraint: never call home.

  • 21shipped features
  • 0servers
  • 30languages

Vaults, including secret ones.

Separate encrypted spaces with separate passwords. Secret vaults never appear in the unlock list — they open only when you type the password.

Sharper replies

Gemma 4 E4B — markedly better answers, tuned for flagship phones. The Light model stays one tap away when you want to spare battery.

Thinking, with tools.

Reasoning mode can call web search mid-thought, read the result, and keep reasoning. Capped at three calls per turn.

See what you show it

Drop in a photo or screenshot and the model reasons about it — entirely on your device. Nothing leaves.

Persistent memory

Pin facts the assistant should remember across every chat in the vault — name, preferences, work shape. Up to 20 short statements. Free does not include memory.

Answers from the live web

Let the assistant pull fresh information from the public web when a question needs it — current prices, news, sports results, release versions. Each result opens inside Tacita's in-app incognito browser, so cookies and history never leak. Pro only.

And 15 more — the rest of the toolkit
  • Conversation, branched.
  • Open formats, no lock-in.
  • Speaks 30 languages.
  • Adapts to your phone.
  • No ads, ever
  • A roster of characters
  • Talk, don't type
  • Browse the model catalog
  • Full sampling control
  • Faces for your characters
  • Civitai, built in
  • Run the big models
  • Same chats, phone and desktop
  • No cloud, no relay, no account
  • Built for power users
Pricing

Pay once. Keep forever.

No subscriptions. Buy once on Google Play (App Store soon) and you own it.

Free €0 Always
  • Conversation, branched.
  • Vaults, including secret ones.
  • Open formats, no lock-in.
  • Speaks 30 languages.
  • Adapts to your phone.
  • Thinking, with tools.
Best value
Pro + Bridge €39.99 One-time. Lifetime.

Everything in Pro, plus Tacita Desktop on your computer.

  • Everything in Pro
  • Your computer joins in
  • Generate images on your GPU
  • Faces for your characters
  • Civitai, built in
  • Run the big models
  • Same chats, phone and desktop
  • No cloud, no relay, no account
  • Built for power users
Pro €19.99 One-time. Lifetime.
  • Sharper replies
  • No ads, ever
  • A roster of characters
  • Answers from the live web
  • See what you show it
  • Talk, don't type
  • Persistent memory
  • Browse the model catalog
  • Full sampling control

€19.99 is the EU base price. Your storefront converts to your local currency and applies regional taxes; the price you see at checkout is the price you pay. Restore the purchase on any device signed into the same store account.

Pro + Bridge — €39.99

Image generation, on your own GPU.

Tacita Desktop runs SD, SDXL, and Flux locally on your computer; the encrypted Bridge streams the result to your phone — chat-side gen, persona avatars, anything you ask for. No server in the loop.

  • Your GPU, not ours

    Models run on the desktop you already own.

  • Encrypted on the wire

    Same Noise transport that protects your chat.

  • Zero plaintext spill

    Desktop overwrites the temp PNG before deleting.

SD 1.xSDXLFluxLoRAs

Encrypted in transit. Wiped on the desktop. Stored encrypted on your phone.

Get Pro + Bridge — €39.99 One-time. No subscription.
Privacy

What we don't do.

Most apps ask you to trust their privacy policy. Tacita is built so there's nothing to trust us with in the first place.

  1. We have no servers.

    Really — there's no cloud infrastructure to hack.

  2. We have no accounts.

    There's no user database. You don't sign up. We can't email you.

  3. We have no telemetry.

    The app sends nothing back. We couldn't tell you how many people use Tacita, or what they write.

  4. We have no backdoor.

    If you forget your password, the data is lost. We can't recover it even if we wanted to.

  5. We don't sell your data.

    We don't have it. See above.

Curious about the cryptography? Tacita ships modern, named primitives — and a signed software bill of materials so anyone can verify the binary they downloaded. See how it's built →

Sealed by default. Verifiable by anyone who reads the binary.

Download

Get Tacita.

One app on your phone. One companion on your computer. Same vault, same key.

FAQ

Common questions.

Short answers to what people ask before they install. Detailed answers, with citations, on the FAQ page.

  1. Does Tacita send my chat to a server?

    No. Tacita has no backend. Every message you write and every reply the model generates is computed and stored entirely on your phone. The app makes only three explicit, user-initiated network calls: downloading a model file, verifying an in-app purchase receipt with RevenueCat, and a one-shot reachability check at startup. None of those carry chat content.

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  2. What happens if I forget my password?

    The conversations are gone. Tacita does not keep a backup, a recovery key, or any kind of backdoor. Your password is the only input that can derive the encryption key, and we never see it. This is the trade-off you accept in exchange for a vault nobody else can open.

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  3. What language model does Tacita run?

    Tacita ships with two curated Gemma 4 instruction-tuned GGUF models: Light (E2B, ~2.89 GiB on disk, 4 GB minimum device RAM) and Pro (E4B, ~4.64 GiB on disk, 8 GB minimum device RAM). Pro users can additionally browse and install other Gemma-family GGUFs (every generation: 1, 2, 3, 3n, 4) directly from Hugging Face inside the app.

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  4. What character card formats does Tacita support?

    Tacita imports the community-standard CCv2 (PNG / APNG with a tEXt chunk keyed "chara"), CCv3 (tEXt chunk keyed "ccv3"), CHARX (a ZIP envelope with card.json at the root), and raw JSON envelopes. Every documented spec field is preserved as a discrete persona field, including the lorebook, alternate greetings, and creator notes.

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  5. How much does Tacita cost?

    The free tier is €0 forever. Tacita Pro is €19.99 paid once — a lifetime in-app purchase. There is no subscription, no recurring charge, and no usage-based billing. Storefronts convert €19.99 to your local currency and apply regional taxes; the price you see at checkout is the price you pay.

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  6. Is Tacita on iOS?

    Not yet. The Android build ships first; the iOS port is in progress and will arrive on the App Store later. The privacy and crypto contract is identical on both platforms.

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See every question we get answered →