Opus 4.7 vs GPT-5.5 vs Gemini 3.1 Ultra: which one should a small business actually use?

Three flagship AI models. Three different price points. Three different strengths. And one question every small business owner I have spoken to in the last fortnight is asking: which one do I actually pay for?

The honest answer is "it depends what you do". The unhelpful answer is "they are all great". This article splits the difference. We are going to walk through the six things small businesses use AI for most often, and tell you which model wins each one. No benchmarks. No vague "all three are good". A real verdict.

If you missed the launches themselves, our May 2026 frontier AI roundup is the quick recap. Otherwise, let us get into it.

The three contenders in one sentence each

• Claude Opus 4.7 (Anthropic). The agentic specialist. Best when you want AI to follow a careful process, take actions, and use a computer for you.
• GPT-5.5 (OpenAI). The fast all-rounder. Best for everyday writing and the broadest plug-in ecosystem, included in your existing ChatGPT subscription.
• Gemini 3.1 Ultra (Google). The long context specialist. Best when you have huge amounts of text, audio, or video to feed it, and when you live in Google Workspace.

Now to the bit you came here for.

Writing and content drafting

Verdict: GPT-5.5 for speed, Opus 4.7 for tone.

If you are writing emails, social posts, blog drafts, and product descriptions, GPT-5.5 is the fastest of the three and it is included with the ChatGPT subscription you probably already have. The output is reliably good, especially for shorter content, and the speed bump in this version is the kind you actually feel.

However. If your business has a distinctive voice, Opus 4.7 follows tone instructions more carefully than the other two. We use Claude for anything where matching a specific writing style matters. The difference is small but real, and over a year of content output it adds up.

Gemini 3.1 Ultra is the third pick here. Not bad, just not the obvious choice for short-form content unless you also need to pull in long source material.

Long document and meeting analysis

Verdict: Gemini 3.1 Ultra, no contest.

This is where the two million token context window earns its keep. If you have ever tried to summarise a 200-page contract, parse a year of customer service tickets, or pull insights out of recorded sales calls, you know the pain of chunking documents up because the AI cannot hold them all at once.

Gemini 3.1 Ultra removes that problem. You drop in the whole thing, ask your question, and it answers from the full source. It is also natively multimodal, so you can hand it a video recording of a meeting and ask "what did the client agree to" without first running the audio through a transcription tool.

Opus 4.7 and GPT-5.5 are both fine for normal document length work, but if "long" or "lots" describes your input, Gemini wins.

Automation and agentic tasks

Verdict: Opus 4.7.

Agentic is the industry word for AI that does things on your behalf rather than just answering questions. Opus 4.7 is the best of the three at this. It can use a computer, follow a long sequence of steps, and stick to precise instructions in a way that GPT-5.5 still struggles with on complex multi-step jobs.

If you have ever wanted AI to "do my weekly report" rather than "help me write my weekly report", this is the model that gets you closest. We covered the broader case for AI automation in how we saved 10 hours a week with AI automation, and Opus 4.7 is the engine that makes that kind of setup more reliable than it was six months ago.

GPT-5.5 is improving fast in this space and is a strong second. If your automation needs are simple, GPT-5.5 inside the OpenAI ecosystem will probably get you 80% of the way there with less setup.

Customer service and voice

Verdict: tie between Opus 4.7 and GPT-5.5, depending on stack.

Voice AI is having a moment. Both Opus 4.7 and GPT-5.5 power customer-service style voice tools through their respective APIs. Which one wins comes down to where the rest of your business already lives.

If you use Microsoft Teams, Word, or Office 365, Anthropic's recent Word integration plus the Opus 4.7 agent capabilities are a natural fit. If you are mostly inside the OpenAI ecosystem with custom GPTs, ChatGPT Team, and Whisper transcription already in play, GPT-5.5 will be easier to wire up.

Gemini 3.1 Ultra is third for this use case mainly because the consumer-facing voice tooling around it is less mature.

Working with Google or Microsoft files

Verdict: Gemini 3.1 Ultra if you are on Google, GPT-5.5 if you are on Microsoft, Opus 4.7 sneaking up on both.

This is less about which model is better and more about which one is integrated where you already work.

Gemini 3.1 Ultra is built into Google Workspace. If your business runs on Gmail, Google Docs, Sheets, and Drive, Gemini is right there in the sidebar of every document you open. That convenience is hard to beat.

GPT-5.5 has the deepest plug-in ecosystem and works well with Microsoft files, especially through ChatGPT's file upload features and the Outlook plug-in.

Opus 4.7 has just landed inside Microsoft Word as a beta, which closes the gap meaningfully. If you live in Word, that is worth keeping an eye on.

Cost and value

Verdict: GPT-5.5 has the best small business pricing today.

For a single user paying out of their own pocket, ChatGPT Plus at the standard monthly rate gets you GPT-5.5 plus the broader OpenAI ecosystem (custom GPTs, image generation, voice, file uploads). It is the most for the money for a non-technical user.

Anthropic's Claude Pro is similarly priced and gets you Opus 4.7 plus Claude Design and Cowork. If you mostly want a writing and reasoning tool with a really nice interface, this is a strong shout. We dug into the broader Claude ecosystem in our plain English tour of Claude.

Gemini Advanced is included in some Google One Premium tiers, which can make it effectively free if you already pay for Google storage. That is the cheapest route into Gemini 3.1 Ultra by some distance.

For a fuller take on whether paid plans are worth it at all, our is paying for AI worth it piece walks through the numbers.

Quick pick by business type

Should you pay for more than one?

For most small businesses, no. One subscription, used well, will get you further than three subscriptions used at 30%.

The exception is if you have one specific high-value workflow that genuinely needs a different model. For example, a small law firm using Gemini 3.1 Ultra for case file analysis and Opus 4.7 for drafting client letters. The cost of two subscriptions is trivial compared with the time saved on either workflow.

If you are not sure, our AI for small business guide has more on building an AI tooling stack without overspending.

My actual pick (yours might differ)

If someone forced me to pick one model for a typical UK small business, today, knowing nothing else about them, I would go with Opus 4.7.

The reason is not benchmarks. It is that the agent capabilities are the most likely to give you a "this changed how I work" moment, rather than just a faster version of what you already do. Speed is nice. Doing things you could not previously do is what actually moves the needle in a business.

That said, if you live in Google Workspace, Gemini 3.1 Ultra inside Docs and Sheets is genuinely brilliant and you should not switch just because of an article. And if you already pay for ChatGPT Plus and your team is happy with it, GPT-5.5 has just made your existing tool quietly better. Inertia wins more decisions than people admit, and that is fine.

Want a steer specific to your business? That is what our free AI audit is for. Or if you want the running shortlist of which tool we recommend for which task, the AI model recommendations page is updated for the May 2026 launches.