Roleplay on your iPhone without running SillyTavern

Updated

SillyTavern is a powerful, self-hosted roleplay front end, and it's built for a computer or server rather than a phone. Castmates is the opposite trade: an iPhone app with the model on the device, nothing to set up, and a lot less control. Here's how to tell which one you want.

Free to start · No account · 100% on-device

What SillyTavern is, and why it's awkward on a phone

SillyTavern is free, open-source software you run yourself. It talks to a model you provide, either one running on your own machine or one you reach through an API. It's popular because you can control almost everything. On an iPhone, that usually means opening it in Safari from a PC or home server that stays on, which works but needs setup and a connection back to that machine. We haven't tested every way people run it on phones, so check the project's own documentation for current options.

Castmates vs. a SillyTavern setup

Castmates SillyTavern
Setup Install from the App Store, one ~2 GB model download Install and host it yourself, then connect a model or API
Where the AI runs On your iPhone Wherever your backend is: your PC, a server or a cloud API
Model choice One model, fixed Almost any model you can run or reach
Characters 35 curated characters, your own, and imported cards Import character cards from the community
Tuning Lorebooks, edit a reply, Continue, branch a chat Prompts, samplers, lorebooks, extensions
Works offline on the phone Yes, after the download Only if the backend is reachable
Cost 30 free messages a day; Pro $6.99 a month, $29.99 a year or $44.99 once Software is free; you pay for your own hardware or API use
Phone requirement iPhone with 6 GB RAM or more Any device with a browser

What you give up with Castmates

Who it suits

If you enjoy tuning your setup, keep SillyTavern. If you've wanted to roleplay on your phone without keeping a computer running or paying for an API, and you don't want an account, Castmates is simpler. It's rated 18+. You can meet the cast before installing, and our private roleplay page explains what stays on the device.

Frequently asked questions

Is there a SillyTavern app for iPhone?
Not an official one that we know of. SillyTavern is a self-hosted web interface, so on an iPhone people usually open it in the browser from a computer or server they run at home. Castmates is a different thing: a native iPhone app where the model runs on the phone itself.
Is Castmates a replacement for SillyTavern?
Only if what you want is simple roleplay on your phone. SillyTavern gives you far more control: pick any model, edit prompts and samplers, use extensions. Castmates imports character cards and lorebooks, but has none of the rest. It trades control for zero setup.
Do I need a server or a PC to use Castmates?
No. Install the app, let a model of about 2 GB download once, and chat. Replies are generated on the iPhone, with no computer and no API key involved.
Which iPhones can run it?
An iPhone with 6 GB of RAM or more and about 2 GB of free storage. On older phones the model won't run well, so a browser-based setup is the better route there.
Can I import character cards or use my own model?
Cards, yes. Castmates imports SillyTavern and Chub cards as PNG or JSON (V1, V2 and V3), with their lorebooks. Your own model, no. Every character runs on the model that ships with the app, and you can't swap it.
Does it work offline?
Yes, after the first model download. Chatting works in airplane mode, and your messages aren't sent to a server.

Try Castmates free

35 characters, 127 scenarios, and every conversation stays on your iPhone.