Incognito, Tuesdays and VPNs: what the evidence says

TL;DR

A study for the European Commission compared visits where 160 websites could or could not see past browsing or how visitors arrived: personalised price differences appeared in only 6% of cases, and were small. It did not test incognito mode. We found no official evidence on booking days. EU nationals and residents cannot be charged more for where they live.¹⁴

Does browsing in incognito mode get you cheaper fares?

The most relevant evidence we found is a study done for the European Commission by Ipsos, London Economics and Deloitte, with an executive summary dated June 2018. The study says it represents the contractor's views, not necessarily the Commission's. Its mystery-shopping exercise covered 160 e-commerce websites in 8 EU Member States, in four markets including airline tickets and hotel rooms, as part of work carried out between December 2016 and November 2017.¹

The study compared visits in which a site could see the visitor's past browsing or how they had reached it (through a search engine, a price comparison website, a different browser or a mobile device) with visits in which it could not.¹ It did not test incognito mode itself.

It did not find consistent and systematic personalised pricing. Price differences between personalised and non-personalised visits appeared in only 6% of situations with identical products; where they appeared, the median difference was less than 1.6%, and prices were not systematically higher or lower when visitors could be identified.¹

Travel sites showed relatively more of it than shops selling TVs and shoes: of the 34 websites where price personalisation was seen, 19 sold airline tickets and 9 sold hotel bookings. The study notes that the ticket sites were platforms selling tickets, not airlines' own websites.¹

What changed far more often was the order of results. Across the 160 sites, 61% personalised the ranking of offers, including 92% of the airline-ticket sites and 76% of the hotel-room sites; arriving through a price comparison website or on a mobile device had the strongest effect.¹

The study itself says its mystery-shopping data should be interpreted with care, because the technology used for online personalisation is extensive, develops rapidly and is hard to detect, and because its sample of 160 websites may not be representative of all EU e-commerce.¹ Separately, it notes that tracking methods such as digital fingerprinting are harder for consumers to prevent or stop than cookies.¹

An earlier academic experiment by researchers at KU Leuven and Inria searched 25 airlines twice a day for 21 days using 66 user profiles and found no evidence of systematic price discrimination, while noting that some airlines' prices were highly volatile.²

What does EU law say about personalised prices?

Personalised pricing is not illegal in the EU, but traders must tell you whether a price has been personalised through automated decision-making and profiling of your behaviour, so you know before you buy.³

For travel tickets bought in the EU, all taxes, fees and charges must be included in the total price from the start of the booking process, and optional extras such as travel insurance may only be offered on an opt-in basis.⁴

If you meet unfair pricing, Your Europe suggests asking your national consumer association or the European Consumer Centres network how to report it.³

Is Tuesday the cheapest day to book?

We looked for official or independent research on which day of the week to book and found none. The figures that circulate online on this come from companies that sell travel, and we do not use them here. Treat any fixed cheapest-day rule as unproven.

Can a VPN get you a lower price?

Inside the EU, if you are an EU national or resident, a trader cannot charge you a higher price just because of your nationality or country of residence.⁴³

For services provided at the trader's premises, such as hotel bookings, car hire or entry tickets for an amusement park, you are entitled to the same prices as local buyers.⁴

Where a trader has several country versions of its website, it cannot redirect you to another version without your explicit permission, and you should be able to change your choice at any time.⁴

Some differences remain lawful: prices can vary with objective factors such as delivery costs, and traders may set different prices in different shops and websites, as long as buyers from other EU countries can access those offers.³

The Commission study found that tools such as VPNs and the Tor browser are rarely used by people shopping online; its summary gives no result on whether they change the prices shown.¹

These protections are for EU nationals and residents buying within the EU. This page is general information. This is not legal advice.

What this page cannot tell you

The evidence is old. The study's fieldwork ran from December 2016 to November 2017, and the academic experiment is older still. Pricing software has changed since, and we did not find a newer official study of this kind.
Small samples. The mystery shopping covered 160 websites in 8 countries, and the study says it may not be representative.
No booking-company statistics. Claims about the cheapest day or the best time to book rely on data from travel sellers, which we do not use.
Flight tickets and geo-blocking. The Your Europe pages we read name hotel bookings and car hire as covered services; we did not confirm how the geo-blocking rules treat flight tickets, because the legal text could not be read when we checked.

Key takeaways

The study did not test incognito mode; where sites could see past browsing or how visitors arrived, it found price differences only rarely, and small ones.
Result ordering is personalised far more often than prices, so compare the same item rather than whatever appears first.
In the EU you have the right to be told if a price was personalised by an algorithm.
What we would skip: paying for a VPN in the hope of a cheaper fare or hotel rate; the evidence we found does not support it.

Sources

The evidence on personalised prices comes from a 2018 study done for the European Commission and one academic paper; the legal position comes from the Commission's Your Europe pages. All were read on 24 September 2026. We did not use statistics from any company that sells travel. See how we research.

Ipsos, London Economics and Deloitte for the European Commission, Consumer market study on online market segmentation through personalised pricing/offers in the European Union: Executive Summary, June 2018 (PDF). Read it. Accessed 24 September 2026. © European Union, 2018, reuse under CC BY 4.0; we summarised it.
Vissers, T., Nikiforakis, N., Bielova, N. and Joosen, W., Crying Wolf? On the Price Discrimination of Online Airline Tickets, HotPETs 2014 (PDF). Read it. Accessed 24 September 2026. Academic paper, cited and summarised; nothing reproduced.
European Commission, Your Europe, Unfair pricing (page last checked by the Commission 30 April 2026). Read it. Accessed 24 September 2026. © European Union, licensed under CC BY 4.0; we summarised it.
European Commission, Your Europe, Pricing and payments (page last checked by the Commission 27 January 2026). Read it. Accessed 24 September 2026. © European Union, licensed under CC BY 4.0; we summarised it.

Changes made. We summarised the study's executive summary and the Your Europe pages (CC BY 4.0) in our own words and selected the figures relevant to travel. The academic paper is cited, not reproduced. We name no booking site, airline or travel seller. This page is not legal or financial advice.