How to Compare Prices Instantly With the Free WEM Chrome Extension

We have all done it. You find something on Amazon, hover over the buy button, and then spend the next fifteen minutes opening tabs across Currys, Argos, John Lewis, and whoever else might stock the same thing. It is tedious, it is time-consuming, and half the time you end up buying from Amazon anyway because you cannot be bothered to check any more sites. There is a better way to do this, and it takes about thirty seconds to set up.

The WEM Chrome extension sits quietly in your browser and does the price comparison legwork for you — automatically, in real time, while you shop. No new tabs, no copying and pasting product names, no guesswork. Here is how it works and why it has become a genuine part of our shopping routine.

What the extension actually does

When you land on a product page on Amazon or eBay, the extension recognises the item and checks prices across the retailers WEM covers. If it finds a lower price elsewhere, a small savings banner appears at the top of the page showing you exactly how much you could save and where. It is not intrusive — there are no pop-ups blocking the page or flashing animations demanding your attention. Just a clean, helpful nudge.

Today the comparisons cover Amazon, eBay, AliExpress, Foot Locker UK and NordVPN, with more UK retailers switching on as their affiliate programmes approve. It checks live prices, so what you see is what you will actually pay if you click through. No bait-and-switch, no outdated pricing data.

How to install it

The whole process takes less than a minute. Genuinely.

1. Head to the Chrome Web Store and search for "WEM" or visit wem3.ai and click the Chrome extension link.
2. Click "Add to Chrome" and confirm the installation when prompted.
3. That is it. There is no account to create, no email to hand over, no settings to configure. It just works.

The extension icon appears in your browser toolbar, and from that point forward it runs automatically whenever you visit a supported product page. You can disable it temporarily by clicking the icon if you ever want to, but most people just leave it running in the background.

What it looks like in practice

Let us walk through a scenario. Say you are browsing Amazon and you land on a pair of Sony WH-1000XM5 headphones priced at £299. Within a couple of seconds, a slim panel appears showing the same headphones listed cheaper on eBay — say £249, a £50 saving. Click through and you are taken straight to that listing. Done.

Another example: you are on eBay looking at a Ninja air fryer. The extension checks the item against the other retailers WEM covers and, if any are cheaper, shows them cheapest-first. No need to open a separate price comparison site, no need to google around — the information comes to you.

The point is simple: you were about to check out on one site, and the panel showed the same item for less somewhere WEM covers — a check you would never have done by hand.

Where it works best

The extension is designed primarily for Amazon and eBay product pages, which is where most UK online shopping starts. It covers electronics, home appliances, beauty products, sports equipment, toys — essentially anything stocked by multiple retailers. It is particularly useful for electronics and appliances, where price differences between retailers tend to be largest.

Categories where we have seen the most consistent savings include:

• Headphones and speakers — the same model often lists at very different prices across Amazon and eBay, sometimes by £30 to £60.
• Kitchen appliances — air fryers, coffee machines, and blenders frequently differ between marketplaces.
• TVs and monitors — large items where even a small percentage gap is real money.
• Beauty tech — hair straighteners, electric toothbrushes, and similar products often vary listing to listing.
• Gaming accessories — controllers, headsets, and peripherals often see listing-specific discounts.

Privacy and trust

This is the part most people ask about first, and rightly so. Browser extensions have a mixed reputation when it comes to privacy, so here is the straightforward version: the WEM extension does not collect personal data. It does not track your browsing history, it does not store your searches, and it does not require you to create an account or sign in. Usage is completely anonymous.

The extension only activates on supported product pages — it is not monitoring everything you do online. When it does activate, the only data it processes is the product information on the page you are viewing, which it uses to find matching prices elsewhere. That is it. No email harvesting, no data selling, no creepy personalisation.

Does it actually save money?

Honestly, not every single time. Some products are priced identically across all retailers, and in those cases the extension simply does not show a banner — it stays out of the way. But for a surprising number of purchases, particularly anything over £50, there are meaningful price differences that most people would never spot without manually checking.

Over a month of regular online shopping, our team found average savings of around £15 to £25 per purchase where the extension flagged a cheaper alternative. On bigger items — a washing machine, a laptop, a premium pair of headphones — the savings were often £40 to £80. Those numbers add up quickly.

Tips for getting the most out of it

• Leave it running — the extension uses minimal resources and only activates on relevant pages, so there is no reason to disable it between shopping sessions.
• Check the banner even if you plan to buy from Amazon — sometimes the price difference is small, but the alternative retailer offers a longer warranty or free next-day delivery.
• Use it during sales events — Black Friday, Prime Day, and January sales are when price discrepancies between retailers are at their widest. What looks like a deal on one site might be cheaper at full price somewhere else.
• Combine with cashback sites — find the cheapest price through the extension, then check if the retailer is on your cashback platform for an extra saving.

Final thoughts

There are plenty of price comparison tools out there, but most of them require you to go to a separate website, search for the product, and sift through results. The reason the WEM extension works so well is that it meets you where you already are — on the product page, at the moment you are making a buying decision. That is when price information is most useful, and that is exactly when it appears.

It is free, it takes thirty seconds to install, it does not ask for your data, and it genuinely saves money. There is not much more to say than that. Give it a go next time you are about to buy something online — the worst that happens is you confirm you were already getting the best price.

Disclosure: some links on this page may be affiliate links. We only recommend products and services we genuinely believe are useful for UK shoppers.