Replika
By Luka, Inc.
Replika is an AI companion app that lets users create and converse with a personalized chatbot designed to build an ongoing relationship over time, offering emotional support, casual conversation, and customizable avatars.
Definition
Replika is an AI companion app that lets users create and converse with a personalized chatbot designed to build an ongoing relationship over time, offering emotional support, casual conversation, and customizable avatars.
Overview
Replika was one of the earliest mainstream AI companion apps, launched by the startup Luka, Inc. before the current wave of large language model-powered chatbots. It lets users create a personal AI companion with a customizable name, appearance, and personality, and is positioned around ongoing relationship-building and emotional support rather than task completion or productivity. Under the hood, Replika uses generative AI models to hold open-ended, memory-aware conversations that reference details a user has previously shared, aiming to feel continuous over weeks and months rather than resetting each session. The app has offered different relationship modes (such as friend, mentor, or romantic partner) and has iterated its underlying models over time as the broader conversational AI field advanced. Replika helped popularize the AI companion category that later saw entrants like Character.AI and Pi, and it has also drawn attention — and some controversy — around the psychological effects of forming attachments to an AI companion, and around abrupt changes to companion behavior when the underlying models or policies are updated.
Key Features
- Customizable AI companion with persistent name, appearance, and personality
- Memory of past conversations for continuity over time
- Multiple relationship modes such as friend or mentor
- Mobile app with chat and voice interaction
- Avatar customization and virtual environment features
- Focus on emotional support and companionship over task completion