Users panned it for its poor functionality and high prices.

The consumer group asked more than 2,200 holidaymakers to rate their experiences using holiday comparison sites over the last two years in a range of categories, including user-friendliness, price and market coverage.

Skyscanner was rated the best comparison site for flights. It was also the only site to score four stars for value for money.

Tripadvisor came second overall and was top of the list for hotel comparison. It received a consistent three stars across all categories in the survey.

Customers said they liked being able to compare prices for a hotel and read customer reviews side by side.

However, earlier this year Which? Travel warned holidaymakers to take these reviews with a pinch of salt after finding evidence that suspicious reviews were artificially raising the profile of some of the highest-rated hotels on the site.

In a separate snapshot investigation, Which? Travel also pitted the seven most used flight comparison sites against each other to see which consistently found the best price.

Skyscanner produced the cheapest price six out of 10 times. Google Flights found the cheapest fare just once. It also found the most expensive fare three times.

For a last-minute return flight to Krakow, Skyscanner was at least £60 cheaper than any of the competitors Which? checked.

When it came to hotel comparison sites, Kayak sourced the cheapest deal in six out of 10 hotel searches, although the savings were relatively small in most cases.

TravelSupermaket came second, finding the cheapest price on four out of 10 occasions – although it also had the most expensive rates on four occasions.

Rory Boland, Which? travel editor, said: “Holidaymakers are known to spend hours and sometimes days looking for the best hotel rates and the best airfares, so for many of us, travel comparison sites are the first port of call.

“There are really only one or two sites you should consider using though if you want to save yourself both money and time.”

A spokesperson for GoCompare said: “We are disappointed by the results of Which?’s research and will be looking over the results to understand where we can improve these services to give people the best experience possible when using GoCompare.”