Free Chrome extension

See the prices other people are seeing.

Priceglass compares your price with recent observations from other opted-in shoppers, making hidden differences visible.

Free. No account. You choose what to share.
Priceglass
Comparing your price
01 The product

With and without Priceglass

The same booking page, twice. Flip the switch and watch what changes.

hotel-meridiana.example/deluxe-double Try it → Priceglass

Hotel Meridiana ★★★★

Via Marina 14, Positano · Show on map · 300 m from the beach
Very good
214 reviews
8.6
Deluxe Double Room with Sea View
1 extra-large double bed · 28 m² · 2 nights · 2 adults
✓ Breakfast included   ✓ Free cancellation before 1 Aug
Only 2 left at this price on this site
Price for 2 nights
€1,240
Includes taxes and charges
Comparing your price…
One other shopper saw this room for less. Click the note.
€135 lower found
€135 lower price observed
Your price€1,240
Lowest observed€1,105
4 comparable checks · newest 5 min ago
Seen by another shopper in a different browsing context. Their price depends on that context, not on a link.

This demonstration uses example numbers. On live pages, the note only appears when another browsing context saw the same offer for less. Priceglass shows you whether your price is fair. It does not promise you can reach the other price, because that price belongs to someone else's context.

02 The problem

Sellers price the person, not just the product

Retailers, airlines, and booking sites use what they know about you, your location, device, currency, and login, to decide which price to show you. Researchers and regulators call this surveillance pricing. From inside one browser it is invisible: you only ever see your own price.

One offer. Five shoppers. Five prices.
03 The answer

It takes a network to see the pattern

No single shopper can see personalized pricing from the inside. A network can. Every person who installs Priceglass adds another vantage point, and every vantage point makes the picture sharper for everyone else.

Shared picture Bob€1,186 Alex€1,240 Eve€1,105 Dana€1,212 You €1,240 €135 lower found
Shoppers share the prices they see.
a price a shopper saw a comparison sent back
  • One shopper sees one price.
  • A network of shoppers sees the pattern.
  • Every install makes hidden differences harder to hide.
04 Evidence

Differences we have observed

CHF 99.90 vs CHF 84.90

The same toy set, checked minutes apart from two browsing contexts in different countries. A 15-franc difference on a single item.

CHF 498 vs CHF 448

The same hotel room, same dates, same occupancy. The price moved 50 francs between two checks minutes apart.

These are observations from our own testing, not marketing claims. A small number of checks shows that a difference existed. It does not prove why.

05 How it works

Three steps, no effort

1

You open a product or booking page

Priceglass reads the visible price and what the offer includes: dates, variant, currency, conditions.

2

It compares recent checks of the same offer

Other opted-in shoppers saw the same offer under comparable conditions. Priceglass lines their prices up against yours.

3

It shows you the difference

A small note appears when someone saw a lower price. You see the evidence and one clear next step, or a plain statement that your price looks consistent.

06 Privacy

What leaves your device, and what never does

Priceglass works only with your permission, and each permission is separate and reversible.

  • Sent: the offer you viewed and its visible price. That is what a comparison needs.
  • Never sent: your name, accounts, passwords, payment pages, or browsing history.
  • Helping others is a separate choice. If you allow it, your browser occasionally checks a public product page for another shopper. These checks carry none of your cookies, run only when your computer sits idle, and stay within a few checks per hour.
  • You stay in control. Pause, reset, or delete your comparison record at any time.
07 Method

What we compare, and when we refuse

A lower price only helps when the offer is truly the same. Priceglass compares prices only when the product, dates, variant, currency, and conditions match.

  • When offers differ in rooms, terms, fees, or availability, Priceglass says so instead of guessing.
  • A handful of checks can show a difference existed. It cannot prove a seller singled you out, and we do not claim it can.
  • Every result shows how many checks it rests on and how old they are.

Am I being shown a fair price?

Install Priceglass and find out. Every install helps the next shopper see clearly too.

Add to Chrome
Free on the Chrome Web Store. Takes a minute.