The catalogue problem
Sites such as Versus, GSMArena and PCPartPicker do one thing very well: they hold a structured record for every phone, laptop or component that a manufacturer has published a specification sheet for, and they let you put two records side by side. If both of the things you are choosing between have a row in that database, use them.
The trouble is how much does not have a row. Two accountants. Two dental clinics. Two tiers of the same software plan. Two universities' versions of the same degree. Two ways of sending money abroad. A moving company against renting a van. Nobody has catalogued these, because there is nothing standard to catalogue — and so the sites that could otherwise help you have nothing to say.
Doing it by hand
Comparing properly without a database is not hard; it is just work, and it goes wrong in predictable places. The method that holds up:
- Write down what actually matters to you before you look at either option — three to five things, in order. Price is usually one of them but rarely the first. If you skip this step, the first thing you read decides the order for you.
- For each of those things, find the answer for each option from the option's own pages: the pricing page, the terms, the "what's included" list. Write the answer down with the address you found it at. Do not take it from a third-party summary; those are often a year old.
- Where the answer is not published, say so in your notes rather than guessing. "Not stated" is a finding — it usually means you have to ask, and how quickly they answer is itself information.
- Now, and only now, read what other people say — reviews, forums, a friend who has used one. You are checking your table against experience, not building the table from opinions.
- Look at the table and pick. If two options tie on everything you listed, the decision does not matter much and you should stop spending time on it.
The failure modes are always the same: comparing on whatever a review happened to mention rather than on what you needed; trusting a number that was true when the article was written; and letting a single loud complaint outweigh everything else.
Doing it in one step
compare⁄io runs that method for you. Type the names of the two to six things — anything you can name — and, in the box beneath, say what matters to you. The comparison then searches the web for each item, writes a verdict for your question, builds a table in which every value carries a badge saying where it was found, and lists the pages it used so you can check them.
Then ask it things. "Which is cheaper over a year?", "Does either one work outside the country?", "What happens if I need to cancel?" — the follow-up chat under every comparison answers from the same research. With more than two options, eliminate them one by one rather than trying to rank all of them at once.
What to watch for
- The comparison is written by an AI model. It can be wrong, and it can be confidently wrong. The source badges and the listed pages exist so that you can check — use them for anything that costs money.
- A value marked "unverified" came from the model's memory, not from the search. Treat it as a prompt to look, not as a fact.
- Prices and plans change. A comparison is a snapshot of the day it was run; if it is a month old, run it again.