Why people look for a Replika alternative
Replika is a cloud app: your messages go to its servers, and you sign in with an account. It is free with in-app purchases and has well over 200,000 ratings on the US App Store. People who want something different usually mention one of three things: they'd rather keep their conversations off a server, they want something that works without a connection, or they want story-driven characters instead of a single companion. We haven't tested Replika's behaviour ourselves, so check its listing for current details.
Castmates vs. Replika
| Castmates | Replika | |
|---|---|---|
| Where the AI runs | On your iPhone | In the cloud |
| Works offline | Yes, after the model download | No (cloud app) |
| Account | None | Privacy labels list an email address and user ID |
| How free use works | 30 messages a day | Free with in-app purchases (App Store listing, Oct 2026) |
| Format | A curated cast of 35 characters, plus your own custom characters | One customizable companion with memory, voice and video calls |
| Age rating | 18+ | 18+ on the App Store |
| App size | 34 MB app plus a ~2 GB model download | About 433 MB |
| Languages | English | 5 listed on the App Store |
| Phone requirement | iPhone with 6 GB RAM or more | iOS 17.0 or later |
Sources: both App Store listings, checked on 9 October 2026. If something in Replika's row is out of date, tell us at [email protected] and we'll fix it.
The honest trade-offs
- You need a recent iPhone. Castmates runs its model on the phone, which takes an iPhone with 6 GB of RAM or more and about 2 GB of free space. On an older phone, a cloud app is the better choice.
- No video calls and no avatar. Castmates has voice calls that run on the phone, in English, but no video and no 3D avatar. If that's what you want from a companion, Replika offers it and we don't.
- Less long-term memory. A model that fits on a phone has a limited context window, so characters won't recall everything across weeks of chats the way a cloud service can.
- English only, iPhone only. No other languages yet, and no Android or web version.
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.
If you also looked at Kindroid, the other companion app people compare with Replika, our Kindroid alternative page covers the differences, including its voice calls and selfies.