Claude vs ChatGPT for business: the one I use, and why

I use Claude. In my work for small businesses, from website copy to SEO research, ChatGPT tends to make things up a bit too often for my liking, while Claude, and its Fable 5.1 model in particular, has been extremely accurate. That is my short answer to Claude vs ChatGPT, and it comes from my own work, not from a benchmark.

Both are good assistants, both have a free plan, and their standard paid plans cost the same in the US. So the useful question is not which one is best in general, but which one gets your tasks right with the fewest corrections. The one-week test at the end of this article is how to find out.

Since AI arrived, my delivery times have shrunk, which sometimes leaves me room to look for extra solutions for a client and build something more complete. If you are still working out where AI fits in your business, start with my guide to AI for small businesses; this article is only about choosing the assistant.

Claude vs ChatGPT at a glance (October 2026)

Claude is made by Anthropic, ChatGPT by OpenAI. Here is how their plans compare for a small business at the time of writing.

These are the US prices each company publishes, on Claude’s pricing page, where they exclude tax, and ChatGPT’s pricing page. I give no pound figures because UK price guides disagree with each other. Anthropic says Pro is priced in your local currency where supported, with tax included in the displayed price in some regions and added at checkout in others. From the UK, check the final £ amount, VAT included, on the checkout page before you pay. Both companies also sell heavy-use tiers, Claude Max from $100 a month and ChatGPT Pro, which most small businesses do not need.

Accuracy: the reason I work with Claude

An AI hallucination is an answer that sounds right and is false: an invented statistic, a feature a tool does not have, a source that does not exist. Every assistant produces some. What matters is how often, on your kind of work.

In my use, ChatGPT tends to hallucinate a bit too much, and Claude, especially Fable 5.1, is extremely accurate. That settles it for me, because much of what I write ends up on a client’s website, under the client’s name. A made-up figure on a service page, or a rule that does not exist in an email to a customer, costs far more than a month’s subscription.

Two caveats, to be fair to both. This is my experience on my own tasks, not a test with a scoring grid, and your tasks may give a different result. And accurate does not mean infallible: whichever assistant you use, check every figure, name, price and date against its source before it goes on a website.

Fable 5.1: what it is and how it is billed

Fable 5.1 is Anthropic’s most capable model at the time of writing, designed for demanding reasoning and long, multi-step work. It is not part of Pro’s included usage: on Pro, Fable runs on usage credits. You switch them on in the web version of Claude, under Settings > Usage (Usage credits, Enable), prepay an amount with Add funds and set a monthly cap with Adjust limit. They are charged at API rates, which for Fable 5.1 are $10 per million input tokens and $50 per million output tokens at the time of writing. Max includes Fable, with its own weekly limit.

The models included in Pro (Opus, Sonnet and Haiku) cover everyday writing. Fable is the one to try on a task where a mistake would be expensive.

Writing website copy: where the difference shows

This is how I write the copy for my website projects, and where the assistant comes in:

1. The brief. I ask what the business offers and which clients it prefers working with, and I advise on what it needs.
2. Identity and layout. I create the visual identity and show it to the client, then choose the page layouts.
3. Research and copy. I do the SEO research and the copywriting, then mix everything together with the assistant, going round again and editing until I am happy with the copy and the site.
4. After the client’s approval. The meta titles and descriptions, and a few SEO articles prepared in advance.

Step 3 is where accuracy pays. A draft that invents a service the client does not offer, or a guarantee nobody gave, has to be caught line by line. The fewer invented details there are to catch, the more editing time goes on tone and rhythm. That is why accuracy is my first criterion when I choose an assistant.

Two instructions reduce invented details with either assistant: limit it to the facts you give it, and tell it what to do when a fact is missing. Anthropic’s own guide to reducing hallucinations starts there: give the model explicit permission to say it does not know. For example:

You are writing the Services page for a plumber in Manchester.
Use only the facts in the brief below. Where a fact you need is
missing, write [TO CONFIRM] in its place, so I can check it.
Tone: plain and confident, short sentences, UK English.

Brief:
- Services: boiler installation, boiler servicing, emergency repairs
- Area: Manchester and Salford
- Preferred clients: homeowners and letting agents

To keep clients apart, use the organisation tools: Claude’s Projects hold the instructions and files for each project (up to five on the free plan), and ChatGPT offers projects too. For the rest of the method, from the inputs to the final edit, see how to make AI writing sound human.

Research for SEO: Claude’s Research vs ChatGPT’s deep research

I use deep research for copywriting and SEO: to find what people complain about most, which gives the copy its angle, and which keywords keep coming back, and in which niches. For the keywords themselves I use Semrush, in particular to see what advertisers pay for each one: that shows which ones work best, and I target those in SEO rather than in paid ads.

In Claude, the feature is called Research, on the Pro, Max, Team and Enterprise plans. Turn on web search, click the + button at the bottom left of the message box, then Research. At the time of writing it runs on Opus 5.5 and uses your limits faster than a normal chat; started from the mobile app, it searches the web only and skips your connectors, such as Gmail or Google Docs. ChatGPT’s equivalent, Deep research, is also started from the + menu of the message box, with limits that depend on your plan.

Accuracy counts twice here: a report that invents a complaint sends the whole page in the wrong direction. Open the sources the report cites, check their dates and drop anything you cannot trace. My step-by-step method, with the prompts, is in how to use Deep Research for copywriting and SEO.

What ChatGPT does better

ChatGPT is a good assistant, and for some businesses it is the better buy.

• Pictures in the conversation. ChatGPT generates images from a description. Claude’s product page lists charts, diagrams, slides and documents, not image generation. For everyday visuals I use Canva anyway: working without it would be like having no kettle in the house.
• A cheaper paid plan. Go costs about $8 a month in the US, with ads. Claude has nothing between its free plan and Pro.
• Habit. If your team already uses ChatGPT and gets good results, switching has a cost in time and in prompts to rewrite. Keep what works.

If images, price or habit matter most to you, ChatGPT is a sound choice. For facts that a client will publish, I want the assistant that makes the fewest mistakes on my work, and for me that is Claude.

Privacy: the training setting to check in both

Both assistants can use the conversations of personal accounts to train their models, and both let you refuse.

• Claude. Since 28 August 2025, Free, Pro and Max users choose in their privacy settings (claude.ai/settings/data-privacy-controls) whether their chats help train Anthropic’s models. If you allow it, data is kept for up to five years; if not, for 30 days. Incognito chats are not used for training, even if you allowed it. Team, Enterprise and the API are not affected (Anthropic’s announcement).
• ChatGPT. On a personal account, open Settings > Data controls and switch off Improve the model for everyone: new conversations stay out of training and remain in your history, on every device (OpenAI’s data controls FAQ). Temporary chats are not used for training and are deleted after 30 days. Content from ChatGPT Business and Enterprise is not used for training by default.

Switching training off does not mean you can paste anything. Your clients’ names, email addresses and phone numbers are personal data under the UK GDPR (and the EU GDPR in France): anonymise what you can, and keep the rest out of personal accounts. As soon as several people share client information, a team plan (Claude Team or ChatGPT Business) is the safer option, with central billing, admin controls and business content kept out of training by default. What you can and cannot share is covered in ChatGPT and GDPR: what client data you can put into an AI assistant.

Which one should you choose?

Choose Claude if most of your AI use is writing and research that other people will read: website pages, articles, proposals, emails to customers. Start with Pro, and add usage credits if you want Fable for the tasks that need it.

Choose ChatGPT if you want pictures in the same tool, if a lower price matters more to you than the accuracy difference I describe above, or if your team already works well with it.

Take a team plan as soon as several people share client information, rather than personal accounts.

Look at the API if what you want is AI inside your own tools: answering website forms, sorting leads, feeding a CRM. Start with my tutorials on the Claude API and the OpenAI API.

And pay for one, not both. Jumping to whichever model was announced last week is the same trap as jumping between marketing channels, which I describe in shiny object syndrome: you get good results from a tool by learning it, and you only learn it by sticking with it.

How to test Claude and ChatGPT in a week before paying

The free plans are enough for a first comparison on your own work. Bear in mind that Claude’s free plan runs Sonnet and Haiku only: Opus comes with Pro, and Fable with Pro’s usage credits or with Max, so the paid month in step 5 is the fairer test of the accuracy I describe. Here is the test I suggest:

1. Pick three real tasks you do every month: a service page, a reply to a difficult customer email, the list of questions your clients ask before buying.
2. Give both assistants the same input: the same instructions, the same facts about your business, the same examples.
3. Check every fact in both answers against its source, and count the errors.
4. Count the edits each answer needs before you would publish or send it.
5. Pay for the winner for one month, billed monthly, before committing to a year (Claude Pro drops from $20 to $17 a month on annual billing).
6. Set the training choice in the settings before you paste any business information.

If your count disagrees with my verdict, trust your count: the right assistant is the one that makes the fewest mistakes on your work, not on mine.