Nyth AI

New: Spark (zero-download AI on iPhone 15 Pro+), Apex reasoning brain, and Nyth Pro with iCloud backup, search, personas and export. Still 100% on-device. No account.

Nyth AI: private AI chat on your iPhone and iPad

Use capable AI without sending your chats to our servers. Nyth runs language models on your device so your conversation text stays local. No account required. Built for people who care about privacy.

BRAINS FOR DIFFERENT JOBS

Choose the model that fits you, or start from Home with a preset and we will route you to the best brain for that flow:

• Flash: Fast answers for quick questions (300 MB) • Nova: General chat and creative brainstorming (1 GB) • Sage: Code, math, and deeper analysis (1.5 GB) • Spark: Apple's on-device AI on supported iPhones and iPads. No download. Instant start. (iPhone 15 Pro and later with Apple Intelligence) • Apex: Our most capable on-device brain. Stronger reasoning, code, and analysis (2.5 GB). Included with Nyth Pro.

Switch brains anytime in the Brains tab.

SMART HOME PRESETS

Code, research, creative writing, business, homework, and more. Each preset is tuned to pick a strong brain for the task.

NATURAL VOICE

• Dictate with the microphone (on-device speech recognition when supported) • Hear replies with spoken output; we clean up markdown so it sounds more natural • Simple recording and playback controls

NYTH PRO (ONE-TIME PURCHASE)

Upgrade once to unlock:

• Apex: Phi-3.5 Mini, our smartest downloadable brain • iCloud Backup: Sync conversations across your iPhone and iPad via your own iCloud (optional; uses your Apple ID storage, not our servers) • Search: Find anything across your saved chats • Export: Share or save conversations as readable text • Custom Personas: Create your own AI personalities with custom instructions

Free tier includes Flash, Nova, Sage, Spark (when eligible), voice I/O, Home presets, and unlimited local chat.

PRIVACY-FIRST

• AI inference on your device after you download a model (Spark uses Apple's built-in model with no download) • We do not run your chat on our servers • No ad or cross-app tracking in the app • Chats are stored on your device; optional iCloud backup stays in your private iCloud container

BEFORE YOU CHAT

Downloading a brain is a one-time fetch over Wi-Fi (typically hundreds of MB up to ~2.5 GB for Apex) from Hugging Face. After that, chat works offline with the models you have installed.

WHO IT IS FOR

Professionals, students, writers, and developers who want capable AI without shipping every message to the cloud.

Nyth AI: local inference. Your data on your device.