Fake reviews are often easy to spot – but, as with financial scams, even the smartest internet user can be fooled. So what are the top tips for avoiding being duped? And which sites can you depend on?

Obvious red flags

Excessive praise and enthusiasm are often signs that the review has been paid for by the product producer, hotel, restaurant, etc. Even more so if this praise comes with little concrete detail. Watch out for wording such as “this product changed my life” or “I can’t believe this is so amazing”, etc. Equally suspicious is the faux humility of sentences such as “I’ve never written a review before, but …”

Typos and weird sentence construction

Most of the human-written fake reviews come from outside the UK (India and Russia lead the way in fake review production, according to Tripadvisor). Many will contain typos, errors and grammar that are likely to indicate the writer is not (as they proclaim in their profile) a native English speaker.

Overly perfect and long sentences, often using American English AI-generated fake reviews tend to have perfect, spellchecked English. Photograph: Espy Photography/Alamy

A feature of the new AI-generated fake reviews is that they tend to use long sentences that most real reviewers would not write. They also have perfect, spellchecked English and grammatical accuracy. The reviews may also run on and on, paragraph after paragraph, which is unusual in most human-written reviews.

AI uses the language of its masters – the American tech companies. So reviews default into American rather than British English – for example, saying transportation rather than transport. But AI is learning very quickly and can be set to write in British English or to use shorter sentences. It may even start throwing in human-style errors to convince readers of its (fake) authenticity.

Unusual distribution of review scores

Most establishments or products will have a bunching of reviews – mostly good, or mostly bad. What is unusual is to have lots of five-star reviews at one end and a whole load of terrible reviews at the other. This pattern may suggest the establishment is paying for or producing lots of five-star reviews to mask the authentic bad reviews it is receiving.

Product providers know most internet users don’t click their way through lots of reviews and look only at the first page. If you have the time, scroll through lots of reviews, clicking on the one- and two-star options to get a better picture of the product or establishment. But be aware that highly negative reviews may also be fake, designed to damage a rival.

Check out the reviewer’s legitimacy and number of reviews

If you can, check if the reviewer has reviews elsewhere. Many accounts are created to post one fake review. If the reviewer has lots of reviews on other products or places, check to see if they are all uncannily positive (and often short).

It’s worth changing filters to remove the sponsored results on Amazon. Photograph: Chris Dorney/Alamy Change your Amazon settings

Amazon searches produce a first page of “featured” products. This will present a lot of “sponsored” results at the top. In the pull-down menu in the top right, switch from “featured” to “avg. customer review”. If nothing else, it removes many of the sponsored results.

Don’t bother clicking on items that have only a few reviews. And when you do open a product page, toggle the review setting between “top reviews” and “most recent” to get a better overall picture.

Go to trusted sites

Almost nothing is fake review-proof. But there are ways you can avoid the con merchants.

Join your street WhatsApp group, if you have one. It can be a brilliant source of local, independent reviews of services – such as genuine recommendations for good plumbers, electricians, builders, etc. They are also useful for finding out which broadband provider is actually good for the area.

Airbnb appears to be fairly robust when it comes to fake reviews – because the reviewer doesn’t get a chance to comment until after they have genuinely stayed at a place. But it is noticeable how glowing the average reviews are – if you see a place with a score much below 4.6 out of 5, go through its reviews very carefully.

Airbnb appears to be fairly robust when it comes to fake reviews. Photograph: Chris Batson/Alamy

We would say this, wouldn’t we, but if you go directly to the Guardian, you can find trustworthy, in-depth and totally independent reviews of things such as electronic products, such as those by our consumer technology editor, Samuel Gibbs.

Big-name publications and websites with reputations to protect, such as Auto Trader, also carry extensive free-to-read expert reviews.

The consumer body Which? runs the Trusted Traders service, which promises that every customer review on the site is verified as genuine by its moderators.

Which? also has its full product review service (it costs from £39.50 for annual membership for the first year) where it tests and reviews everything from TVs and washing machines to diets, investments and broadband providers.

Finally, watch out for fake endorsements from celebrities. The MoneySavingExpert founder and TV presenter Martin Lewis’s image in particular is often used by scammers to claim, falsely, that he endorses all manner of goods from cryptocurrencies to bogus investment opportunities. This can even extend to “deepfake” videos created with AI that, sadly, are only going to get more and more realistic.