Mnemosphere

Mnemosphere is an AI research workspace that aggregates multiple frontier models into a single interface, enabling side-by-side comparisons and advanced productivity tools like parallel prompts and instant mindmaps. It supports models such as GPT-5.5o3, Claude 4.6 Sonnet, Gemini 3.1 Pro, DeepSeek V4 Pro, Grok 4.2, and Perplexity Sonar, plus reasoning models OpenAI o3 and Claude Opus 4.7 Extended Thinking. The platform runs in a web browser and is developed by Mnemosphere AI.

What is Mnemosphere?

Mnemosphere is a web-based AI research tool that lets users interact with multiple large language models simultaneously. It takes text prompts (and file uploads up to 5 attachments per question, including PDFs, CSVs, images, and code files) and produces responses from chosen models. The platform is built for professionals who need to compare outputs, explore multiple angles, and organize insights efficiently.

Key Features

• Multi-model streaming — Send a single prompt to up to three frontier models (e.g., GPT-5.5, Claude 4.6, Gemini 3.1) and see their responses side-by-side in real time. Each model is aware of the others’ answers, enabling cross-model questions like "GPT, what do you think of Gemini's answer?".
• Parallel prompts — Fire multiple prompts at once (e.g., explain quantum computing to five different audiences) and see all answers in one view, compressing hours of research into seconds.
• 1-click mindmaps — Transform any AI answer into an interactive mindmap to visualize connections between ideas, with clickable nodes for deeper exploration.
• Critique mode — Ask Mnemosphere to critique an AI’s answer, identifying gaps and generating improved responses.
• YouTube chat — Paste a YouTube URL and query the video’s transcript, comments, and key moments as if it were a document.
• Highlighter + Notes — Highlight text in AI responses and add personal notes that are saved and linkable, allowing you to jump back to the exact spot later.
• Lite Threads — Open a side-chat for quick clarifications without disrupting the main conversation, keeping your primary thread clean.
• Conversation Index — A table of contents for long chat logs, enabling quick navigation across hundreds of questions.
• Prompt Assist — A dropdown of power phrases (e.g., "Explain it like…", "Repurpose", "Debate") that drop into your prompt in one tap, improving inputs without needing prompt-engineering expertise.

Who is it for?

Mnemosphere is designed for researchers, founders, product managers, and analysts who need to synthesize information from multiple AI perspectives. It is also used by over 500 professionals who require deep research capabilities and efficient comparison of model outputs.

What can you do with Mnemosphere?

• Compare model outputs — Run the same prompt across GPT-5.5, Claude 4.6, and Gemini 3.1 to see how each responds, then ask one model to critique another’s answer.
• Parallel research — Submit multiple research questions simultaneously (e.g., explain quantum computing to different audiences) and see all answers in one view.
• Deep research — Fire deep research requests to OpenAI, Gemini, and Perplexity in parallel, then compare synthesized reports.
• Analyze video content — Paste a YouTube link and ask questions about the transcript, comments, or key moments without watching the full video.

Pricing

Mnemosphere offers two paid plans: Pro at $25/month (up to 200 messages per month) and Ultra at $39/month (up to 1000 messages per month). There is no free plan. Both plans include access to all frontier models and features, with Ultra adding personalized support and early access to experimental features.

FAQ

Which models are supported?

Mnemosphere supports every frontier model as they ship. Current flagship models include GPT-5.5o3, Claude 4.6 Sonnet and Opus 4.7 (with extended thinking), Gemini 3.1 Pro, DeepSeek V4 Pro, Grok 4.2, and Perplexity Sonar. Reasoning models like OpenAI o3 and Claude Opus 4.7 Extended Thinking are also available.

Is there a free plan?

No. Mnemosphere is a professional tool with paid plans only, starting at $25/month. All plans provide full access to every model and feature without a watered-down free tier.

How does multi-model streaming work?

You select up to three models for a prompt. They reply simultaneously in a single view. Each model sees the others’ responses, allowing cross-model dialogue. You can swap models mid-conversation without losing context.

Can I upload files?

Yes. You can upload PDFs, CSVs, Excel files, images, code files (.py, .html, .json, .js), and URLs (YouTube or web pages). Up to five attachments per question are supported.

Is my data used for training?

No. Mnemosphere explicitly states that your prompts, uploads, and chats are never used to train any model. Your research data remains private.