Why people look for an AI Dungeon alternative
AI Dungeon is an online game, and its story responses come from models it runs on its own servers. People who look for something else usually want one of three things: a story that works without a connection, chats that stay on their own device, or a set of characters that keep their voice from one conversation to the next instead of a free-form adventure. We haven't tested AI Dungeon's current plans ourselves, so check its site for the latest details.
Castmates vs. AI Dungeon
| Castmates | AI Dungeon | |
|---|---|---|
| Where the AI runs | On your iPhone | On its servers |
| Works offline | Yes, after the model download | No, it needs a connection |
| Account | None | An account to save your adventures (check its site) |
| How free use works | 30 messages a day | A free tier, with paid plans for more credits and larger models (check its site for current prices) |
| Model choice | One built-in model | Several models, including larger cloud models on paid plans |
| Format | A cast of 35 characters, plus custom characters you build | Open-ended text adventure, with scenarios and community-made adventures |
| Platforms | iPhone app | Web, and mobile apps |
| Age | 18+ | See its own terms |
| Phone requirement | iPhone with 6 GB RAM or more, ~2 GB model download | Any device with a browser or a supported app |
Sources: the Castmates App Store listing, and AI Dungeon's public site and app listings, checked on 9 October 2026. AI Dungeon's plans and prices change, so check its site before you subscribe. If something in AI Dungeon's column is out of date, tell us at [email protected] and we'll fix it.
The honest trade-offs
- AI Dungeon is better for open-ended adventures. You can take a story anywhere, and it has scenarios and community-made adventures to start from. Castmates is built around a fixed cast, not a blank page.
- AI Dungeon has bigger models. Its paid plans give access to larger cloud models with longer memory. A model that fits on a phone is smaller, so long chats won't recall as much.
- AI Dungeon runs on more devices. It works on the web and on other phones. Castmates needs an iPhone with 6 GB of RAM or more, and it's English only for now.
- Fewer characters, fewer choices. Castmates has 35 written characters and no model picker. It isn't a general story engine.
What you get instead
Every reply is generated on your iPhone, so your messages aren't sent to a server, there's no account to make, and it works in airplane mode once the model is installed. The free plan gives you 30 messages a day with the full cast and one custom character. Pro lifts the daily limit and the character cap.