ChatGPT, Gemini, Claude, Lumo, Grok and Copilot are all general-purpose AI assistants.

They are built around markedly different priorities: overall capability, integration with existing platforms, privacy, integration with wider platforms or access to live social data.

Popular AI assistants

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

OpenAI's ChatGPT

ChatGPT, developed by OpenAI, is 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.

Anthropic's Claude

Claude, developed by Anthropic, occupies a middle ground between raw capability and responsible AI design. Built around the concept of "Constitutional AI," Claude emphasises helpfulness, honesty and harmlessness as core principles. It excels at long-form content generation, document analysis and nuanced conversation, often matching or exceeding ChatGPT in tasks requiring careful reasoning and ethical judgment. Claude's interface is notably clean and focused, with strong support for uploading and working with lengthy documents—a feature particularly valuable for researchers, writers and professionals handling complex materials. However, Claude tends to be more conservative in its responses, sometimes declining tasks that other assistants would attempt, which can feel restrictive to users seeking maximum flexibility. Like Gemini, it lacks the privacy-first architecture of Lumo and the real-time social connectivity of Grok, positioning itself instead as a balanced option for users who want strong performance without compromising on safety considerations.

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.

Microsoft's Copilot

Copilot is deeply integrated the Windows operating system and the Microsoft 365 suite. Unlike the standalone nature of ChatGPT or the privacy focus of Lumo, Copilot is designed as a productivity layer that can draft documents, summarise meetings, generate images via DALL-E 3 and search the live web simultaneously. It offers a unique "Pro" mode for more complex reasoning and is freely accessible to most users, making it a highly versatile entry point. However, its performance can vary depending on whether it is accessed via the web, the mobile app or embedded within Office apps, and its heavy reliance on Microsoft's ecosystem means it feels most powerful to users already invested in that environment. While it offers better real-time search capabilities than many competitors, it does not match Lumo's privacy standards or Grok's social media immediacy.

Google's Gemini

Gemini, Google’s flagship AI system, is more clearly positioned as an extension of the Google ecosystem. Its strengths are most clearly seen 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.

Which is best?

With five distinct options now available, the "best" choice depends entirely on your primary use case rather than a single metric of intelligence.

Best All-Rounder

ChatGPT For users who need a single tool to handle everything from creative writing and coding to complex data analysis, ChatGPT remains the most capable general-purpose assistant. It offers the deepest reasoning and the widest range of features, making it the safest bet for those who prioritise raw capability and flexibility above all else.

Best for Privacy

Lumo If you are handling sensitive legal, medical or corporate data, Lumo is the only assistant designed with zero-access encryption and minimal data retention as its core philosophy. While it may lack the advanced features of its competitors, it is the superior choice for anyone who cannot risk their conversations being logged or used for training.

Best Integrated Assistant

Microsoft Copilot For professionals living inside the Microsoft ecosystem, Copilot offers the highest utility by bridging the gap between AI and daily productivity tools. Its ability to act directly within Word, Excel and Outlook makes it the most practical "assistant" for office workflows, surpassing others in seamless integration.

Honourable mentions:

  • Google Gemini is the best choice for users deeply embedded in Google Workspace who need quick access to Gmail and Drive data.
  • Grok stands alone for those who need real-time insights into breaking news and social media trends.

Ultimately, the landscape has shifted from a race for the smartest model to a range of specialised tools. The most effective strategy for many users may be to keep ChatGPT or Copilot for daily tasks while reserving Lumo for confidential matters.