The AI Companion Glossary
The words that come up around AI girlfriend and companion apps, defined in plain language. If a term on our rankings or in the blog tripped you up, it is probably here. Every app in this category is for adults 18+.
- AI companion Basics
- An app or platform that holds a persistent, personalized conversation as a chosen character, often adding voice, images and memory. "AI girlfriend" and "AI boyfriend" apps are AI companions with a romantic framing. The ten apps we rank are all AI companions of one style or another.
- LLM (Large Language Model) Under the hood
- The AI model that writes a companion's text. It predicts language from patterns learned in training, which is why staying in character depends on how well the product keeps feeding the model the persona. Better LLMs hold a personality more consistently.
- NSFW Content
- Not Safe For Work: adult or explicit content. "NSFW-capable" apps allow it for adults 18+; the feature exists on some platforms and is filtered out on others. We note each app's policy in the comparison table.
- SFW Content
- Safe For Work: non-explicit content. "SFW-leaning" apps like Replika keep conversations away from explicit territory by design, trading heat for a gentler, lower-pressure feel.
- Persona Character
- The defined personality, look and backstory a companion holds. A strong persona stays consistent across a conversation and, on apps with memory, across sessions. Our characters page tours common persona archetypes.
- Hearts / credits Pricing
- A pay-per-use virtual currency some apps use instead of a flat subscription. Swipey AI uses hearts: you spend them on premium actions rather than paying a fixed monthly fee. Both models are legitimate; what matters is seeing the cost before you pay it.
- Roleplay Feature
- Playing out a scene or scenario with a companion, such as a particular setting or dynamic. Better apps keep the character inside the scene without needing constant reminders of where you are and who she is.
- Context window Under the hood
- How much recent conversation the model can consider at once. A larger window means the companion keeps more of the current chat in mind before older lines fall out of view. It is not the same as long-term memory.
- Memory Feature
- A system that stores details beyond the context window so a companion can recall them in future sessions. Memory is the single ingredient that most separates a companion from a plain chatbot. We go deep on it in our memory explainer.
- Image generation Feature
- Creating pictures of a companion from a text prompt or her defined look. On NSFW-capable apps this can include adult imagery for 18+ users. Image quality varies widely; Candy AI leads on it in our comparison.
- Voice / TTS Feature
- Text-to-speech that lets a companion speak. Good voice adds tone and warmth that text cannot, but only when it matches the character. A mismatched voice can break the illusion faster than no voice at all.
- Character card Character
- A shareable bundle of a persona's traits, backstory and settings, common on community-driven platforms. It is a starting template; the live conversation is where the character actually forms.
- Jailbreak Content
- Attempting to trick a filtered model into producing content it normally blocks. We do not recommend it: it is against most platforms' terms, and choosing an NSFW-capable app built for adults is the honest route to adult content.
- Freemium Pricing
- A model where the app is free to start with paid upgrades. Most companion apps are freemium. The free tier's generosity varies enormously; Character.AI's is the most open, while image-first apps often gate the good parts.