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Copilot, ChatGPT, Claude or Gemini? Choosing an AI assistant

They're all capable. The right choice depends less on which is "best" and more on how your business already works.

Spark-AI7 min readUpdated October 2026

The leading general-purpose AI assistants can all draft, summarise, analyse and brainstorm well. Their features and prices change frequently, so rather than a league table that's out of date next month, here's how to think about the choice.

The main options

Microsoft 365 Copilot

Built into Word, Excel, Outlook, PowerPoint and Teams, and able to work with your organisation's Microsoft 365 content, subject to your permissions and plan. The natural choice to evaluate if your business already runs on Microsoft 365, because AI appears where people already work.

Google Gemini

Google's assistant, integrated with Gmail, Docs, Sheets and the rest of Google Workspace on eligible plans. The equivalent choice to evaluate if you run on Google Workspace.

ChatGPT

OpenAI's assistant, which brought generative AI into the mainstream. A strong all-rounder with a wide range of features, and business plans with admin controls.

Claude

Anthropic's assistant, well regarded for writing quality, working with long documents and careful reasoning, with business plans and admin controls. For transparency: the assistants on this website are built with Claude.

Five questions that matter more than benchmarks

  1. Where does your work already live? If your documents and email are in Microsoft 365 or Google Workspace, the built-in assistant may save the most time, because it can work with that content directly.
  2. What are the data terms? Check that the plan you choose doesn't use your data to train models, offers a data processing agreement, and suits your UK GDPR obligations. See using AI tools safely.
  3. Can you manage it? Business plans let you control who has access, keep work in company accounts and remove access when someone leaves.
  4. What will people actually use it for? Writing-heavy teams, number-crunching teams and customer-facing teams may each prefer different strengths.
  5. What's the real cost? Most business plans are priced per user per month. You may not need a licence for everyone. Start with the people who'll use it most.

How to trial before you commit

  1. Pick two candidates that fit where your work lives.
  2. Choose three real, everyday tasks with no sensitive data, such as a customer email, a document summary and a social post.
  3. Have two or three people run the same tasks in both tools for a week or two.
  4. Compare quality, ease of use and how much editing the output needed.
  5. Decide, then buy business licences for the people who'll benefit most.

Don't overthink it. The difference between the leading assistants matters far less than whether your team actually uses one well. Habits, prompts and good rules deliver most of the value.

Beyond general assistants

Once your team is comfortable, specialist tools may add more value: AI in your accounting software, customer service chat assistants, or automations that connect your systems. These work best when they solve a specific, measured problem. See using AI for customer enquiries for one example.