The one question to ask of any AI comparison
Did it look anything up? A language model answering from memory will give a confident, well-written comparison of two phones with last year's prices, or of a product released after it was trained as though it did not exist. Every tool below can be wrong; the useful ones show you where each fact came from, so you can tell which parts to check.
The kinds of tool
| Tool | What it does | Watch for |
|---|---|---|
| A general AI chat (ChatGPT, Gemini, Claude) | Compares anything in conversation; most can search the web when asked | Whether it actually searched; the answer lives in a chat rather than a page you can share or come back to |
| ChatGPT shopping research | Asks about your budget and needs, researches retail sites and writes a buyer's guide (launched November 2025) | OpenAI's own figure: 52% product accuracy on multi-constraint queries. It says the model may get price and availability wrong — check with the shop |
| Single-purpose AI comparison sites (for example CompareAI, compare-anythings.com) | Two items, researched from several web sources, scored per dimension with pros and cons | Two items at a time; a score per dimension has the same weakness as any score — it does not know what matters to you |
| compare⁄io | Two to six items, a live search per comparison, a verdict for your stated needs, a sourced table, follow-up chat and elimination | It can be wrong too. Values the search did not confirm are badged as such; the pages read are listed under every result |
How to check an AI comparison in two minutes
- Find the one or two facts the decision actually turns on — usually price and one feature.
- Check those two against the maker's own page. Not a review, not a forum: the maker.
- Look for anything stated as a number with no source. Treat it as a guess.
- Ask a follow-up the tool should only be able to answer if it researched properly: "what do owners complain about most?" A vague answer is a sign it did not look.
Which to use
- Shopping for one product in a well-covered category and happy to answer questions first → ChatGPT shopping research is built for exactly that.
- Two well-known things and a quick answer → any of them.
- Three to six options, things that are not products, or a result you want to share or come back to → [compare⁄io](/).
- Discovering what exists in the first place → an alternatives directory. See comparison sites and their alternatives.
Questions people ask
Is there a free AI comparison tool?
Yes, several. compare⁄io gives five comparisons a day free, with live search, follow-up chat and elimination included and no account needed.
Can ChatGPT compare products?
Yes, and since November 2025 it has a shopping research mode for it. OpenAI itself reports 52% product accuracy on queries with several requirements and says the model can be wrong about price and availability, so check the details with the shop before buying.
Are AI comparisons accurate?
Sometimes very, sometimes not. Accuracy depends mostly on whether the tool searched and on whether the facts are published at all. Prefer tools that list their sources, and check the one or two facts your decision depends on.