- NSFW Not safe for work
- Adult or sexual content. An app that is NSFW-capable allows this for verified adults across chat, images or voice; others filter or block it. On our grid this single row often decides a comparison, because Swipey AI allows it plainly while Character.AI blocks it and Replika restricts it.
- SFW Safe for work
- Non-explicit content only. An SFW-leaning app keeps romance and adult material off the table by design. That is a limitation if you want open romance and a feature if you do not: some people specifically want a companion that stays safe.
- LLM Large language model
- The underlying AI that turns your messages into the companion's replies. Different apps use different models, which is a big part of why chat quality varies. You do not need to know which model an app runs, only that it shapes how natural and consistent the conversation feels.
- Persona
- A single companion identity: its personality, look, voice and memory bundled together. Some apps give you one persona to nurture (Replika's model); others, like Swipey, let one account hold several distinct personas you switch between without losing each thread.
- Hearts / credits
- Pay-as-you-go tokens spent on premium actions such as image generation or voice minutes, instead of a flat monthly fee. Swipey uses a hearts credit system, so light users stay effectively free and heavy users pay for what they consume. The trade-off: a very heavy month can out-cost a subscription.
- Roleplay RP
- A scenario-driven conversation where you and the companion play defined roles, like a teacher, a nurse or a stranger. Roleplay-first apps lean on a large character library and scenario tools; the quality depends on how well the model stays in character across a long session.
- Image generation
- The app produces pictures of your companion on request. Two shapes exist: generated photos created in the flow of chat (Swipey, Candy) and rendered avatars you dress and pose (Replika). Generated images tend to match the conversation; avatars give you fine control over a fixed character.
- Voice chat
- The companion speaks replies out loud and can often listen back. Most top apps support it. It matters most for archetypes that live on back-and-forth, where hearing a reply lands differently than reading one. On integrated apps, voice shares the same conversation thread as chat and images.
- Memory / context
- How much of your history the companion carries forward. Short context resets often and forgets last week; long-term memory keeps names, history and running threads for months. It is the stat memory-focused apps like Nomi specialise in, and it is what makes a relationship feel continuous.
- Free tier
- What you can do without paying. A generous free tier (Character.AI) lets you use the app meaningfully for free; a limited one is a taster that pushes you to subscribe. Free to start is not the same as free to use heavily, so match the tier to your habits.
- Filter
- An automated guardrail that blocks certain content. On SFW apps the filter enforces the content policy; users sometimes hit it mid-conversation, which is the "filter roulette" complaint. A stated, stable policy (like Swipey's NSFW-allowed stance for adults) avoids surprise blocks either way.
- Avatar
- A visual representation of the companion, usually a 3D or illustrated model you customise. Distinct from generated images: an avatar is a consistent character you style once, while generated images are fresh pictures produced per request. Some apps offer one, some the other, a few both.