General-purpose AI assistants

Four AI assistants compared by power, privacy, integration and real-time awareness.

ChatGPT, Gemini, Lumo and Grok are all general-purpose AI assistants, but they are built around markedly different priorities: overall capability, integration with existing platforms, privacy, or access to live social data.

OpenAI's ChatGPT

ChatGPT, developed by OpenAI, is best described as the most balanced and widely used option. It is designed as a strong generalist, performing well in long-form writing, coding, explanation, research and structured reasoning. Many users treat it as a thinking partner or productivity aid rather than a simple question-and-answer tool. Its key strengths lie in conversational depth, flexibility and creative output. The main drawbacks are privacy considerations, conversations are stored on OpenAI’s servers, even if training can be limited, and the fact that it does not automatically have access to real-time information unless browsing is enabled. As with any large language model, it can occasionally present incorrect information with undue confidence.

Google's Gemini

Gemini, Google’s flagship AI system, is more clearly positioned as an extension of the Google ecosystem. Its strengths are most evident when used alongside Gmail, Docs, Calendar, Maps and Google Search, and it benefits from access to up-to-date information through Google’s infrastructure. Gemini functions less as a free-form conversational partner and more as a practical assistant, helping users summarise emails, plan journeys or quickly retrieve factual information. However, its long-form reasoning and creative writing are often perceived as less nuanced than ChatGPT’s, and users with strong privacy concerns may be uncomfortable with its deep integration into Google’s data environment.

Proton's Lumo

Lumo, developed by Proton, takes a fundamentally different approach by placing privacy at the centre of its design. It is intended for users who wish to work with sensitive or confidential material without their conversations being logged, analysed or used for model training. Messages are encrypted, data retention is minimal, and the service operates under European data-protection standards. The trade-off is performance: Lumo is generally less capable in terms of reasoning depth, creativity and advanced features when compared with ChatGPT or Gemini. Its value lies not in being the most powerful assistant, but in being the most privacy-respecting.

Twitter's Grok

Grok, created by xAI and integrated directly into X (formerly Twitter), is distinct in its emphasis on live social data. Its defining feature is real-time access to conversations and trends on Twitter, making it particularly useful for following breaking news, public debate and online culture as events unfold. Grok’s tone is often more informal and provocative than that of other assistants, reflecting its close connection to a social media platform. While this can be useful for commentary and trend analysis, it makes Grok less suitable for careful research, technical work or neutral, measured explanations. As with any tool embedded in a social network, privacy considerations are closely tied to the policies and practices of the platform itself.

In practice, each assistant serves a different type of user:

• Choose ChatGPT if you want the strongest all-round assistant for writing, coding, analysis and general problem-solving, and you value depth and flexibility over strict privacy guarantees.

• Choose Gemini if you rely heavily on Google services and want an AI that integrates seamlessly with Search, Gmail and Docs, with easy access to up-to-date information.

• Choose Lumo if privacy is your top priority and you need an AI you can use for sensitive or confidential work, even if that means accepting fewer features and lower overall capability.

• Choose Grok if you are interested in real-time discussion, breaking news and online culture, and want an assistant closely connected to what people are saying on Twitter right now.