Chub AI

Chub AI emerged from the merger of two earlier projects: Venus AI (a roleplay chat interface) and CharacterHub (a public repository of AI character cards).

The combined platform launched around 2023 and has grown steadily since, pulling between 7.5 million and 13.9 million monthly visits according to web analytics data from 2025.

It’s unfunded – no VC backing, no disclosed parent company – which explains both its scrappy, community-driven feel and its occasional infrastructure issues.

The platform runs entirely in a browser. Apple removed the Chub AI app in 2025 because the underlying AI models generated content that violated Apple’s guidelines.

After two weeks of testing across both Mercury and Mars tiers, my honest take is this: Chub AI is the right tool for the wrong audience. It’s marketed broadly as an AI companion platform, but it actually serves a narrow, technically-inclined user base – writers, worldbuilders, and roleplay veterans who want to configure every aspect of how their AI behaves. 

If you fall into that group, Chub AI delivers depth nobody else matches at this price. If you don’t, the learning curve will exhaust you before you ever see what the platform is capable of. I’d genuinely recommend it to a friend writing a serial novel with an AI co-writer. I wouldn’t recommend it to a friend looking for a casual AI chat experience.

Key Features

1. Lorebooks

Lorebooks are Chub AI’s most practical feature for anyone writing long-form stories. Think of them as reference documents the AI consults during conversation. 

You fill a Lorebook with character backstories, location descriptions, historical events, magic systems – whatever your story world needs – and the AI pulls relevant entries into its context window automatically.

I built a Lorebook for a fantasy setting with 12 location entries, 6 character backstories, and a magic system with defined rules. Over a 40-message conversation, the AI correctly referenced location details when the story moved between settings and applied the magic rules consistently.

It wasn’t perfect – one character’s eye color changed between messages 22 and 31 – but the consistency was meaningfully better than chatting without a Lorebook.

The limitation? You have to build and maintain Lorebooks manually. There’s no AI-assisted generation, no auto-population from your conversation history. It’s a writing tool, not a magic button.

2. Model Selection and Memory

This is where Chub AI separates itself from every mainstream competitor. You choose which AI model powers your conversation. 

Mercury users get MythoMax 13B and Mistral 7B. Mars users get Soji 671B, Asha 70B, and Mixtral 8x7B. If none of those suit you, connect your own API key and use GPT-4, Claude, NovelAI, KoboldAI, or any OpenRouter-compatible model.

Switching models between conversations is straightforward. The character definitions, Lorebooks, and chat settings stay consistent regardless of which backend is active, which matters when you’re balancing response quality against API costs.

The memory window (context size) is the technical factor most users underestimate. 

It determines how many previous messages the AI reads before generating a reply. Short context means the AI forgets things quickly. Chub AI’s newer configurations support larger windows, but you still need to configure them properly. 

Mercury’s 8K token window works for casual conversations. For multi-session storytelling, Mars or a high-context external model is necessary.

3. Community Library and Character Discovery

The 60,000+ character library is searchable by tags, categories, and popularity.

You can browse by genre (fantasy, sci-fi, slice-of-life, historical), preset relationship type, or specific tropes. Each character card shows total interactions, ratings, and a preview of the character’s personality before you start a conversation.

What’s Good

The depth of customization has no real equivalent at this price point. Character cards, Lorebooks, model switching, adjustable memory settings, and conversation export combine into a toolkit that treats users like collaborators, not consumers. 

If you want to control every aspect of how an AI character behaves, responds, and remembers, Chub AI gives you more levers to pull than Character.AI, Janitor AI, or CrushOn AI.

The $5/month Mercury plan makes advanced AI roleplay accessible. Character.AI charges $9.99/month for a proprietary model you can’t swap out. CrushOn AI charges $5.99/month with limited model options. Chub AI’s $5 entry tier – plus the option to bring your own API key on any plan, gives budget-conscious users real flexibility.

The community library is massive and constantly growing. With 60,000+ characters spanning every genre and premise, you’ll rarely need to build from scratch unless you want something highly specific.

What Needs Work

The learning curve is real and documented. Multiple reviewers across G2, DreamGen, and WeavAI flag the interface as unfriendly to beginners. 

Character card syntax, Lorebook formatting, model configuration, and memory settings all require reading documentation before you get good results. If you want a plug-and-play experience, Character.AI or CrushOn AI are easier starting points.

Server instability is an ongoing issue. Users report slowdowns during peak hours, occasional UI crashes, and inconsistent response times. Janitor AI – Chub’s most direct competitor – is generally considered more stable in 2026 according to multiple comparison reviews.

No iOS app hurts accessibility. Apple’s removal in 2025 means mobile users are limited to the browser experience, which works but isn’t optimized for smaller screens.

Character quality is inconsistent because the library is entirely community-created. 

Some characters have detailed, well-written personas that produce engaging conversations. Others have sparse definitions that lead to generic, repetitive responses. There’s no quality curation or rating system sophisticated enough to reliably surface the best content.

The English-only interface limits the international audience. While the AI models themselves can respond in multiple languages, the platform interface, documentation, and community forums are entirely in English.

Competitors Comparison