What the Klarna browser extension does on your Shopify store, and how to control it

It's Monday after your creator's weekend push. Their email says link clicks rose but commissions didn't. You open the affiliate report and find Klarna credited with a run of the weekend's orders. Your store doesn't offer Klarna at checkout.

Your developer explains: it's the Klarna browser extension, testing codes and offering shoppers a one-time card. Someone remembers creators sued over affiliate credit; nobody knows how it ended.

This guide covers what the Klarna browser extension does on your Shopify store, who pays for codes and cash back, what reaches you through its card, whether it leaves your partners' clicks alone, and what you can control before peak.

What does the extension do on a Shopify store?#

At checkout, the Klarna browser extension tests codes with one click and applies the best one; where Klarna has a deal, it offers cash back or points. On stores without Klarna, it can offer a one-time Visa card wherever Klarna enables it. Affiliate networks record coupon, cash back and points use to calculate a potential commission to Klarna. [Chrome Web Store, Oct 2026] (opens the source)[Klarna, Mar 2023] (opens the source)[Klarna Inc., Aug 2026] (opens the source)

A coupon extension finds and tries codes; a cashback extension offers a reward linked to a purchase. Klarna combines both with financing. Its Chrome listing, read on 19 October 2026, says it finds coupons and points at over 20,000 stores. Its FAQ, as archived on 15 April 2026, said it tested available codes and alerted shoppers only when a deal or reward existed. The same page said it would scour the internet for coupons; it didn't say whether codes shoppers type are collected. [Chrome Web Store, Oct 2026] (opens the source)[Klarna US (Wayback Machine capture), Apr 2026] (opens the source)

Klarna bought Piggy for automatic couponing, when Piggy had 1.2 million users, and launched this extension in December 2021. That acquisition figure isn't today's audience. [TechCrunch, Dec 2021] (opens the source)[Klarna, Dec 2021] (opens the source)

The manifest in its Chrome listing, version 6.26.25.293, updated 19 June 2026, declares host access to every http and https site. Its content script runs on every page at document_start, as loading begins. Its listing says Klarna asks to read and change all your data on the websites you visit. It doesn't request Chrome's cookies permission, so the manifest doesn't show how affiliate tracking changes after activation. The browser extension permissions entry explains that access; Klarna's US privacy notice says it receives the domains visited. [Chrome Web Store, Oct 2026] (opens the source)[Klarna Inc., Oct 2026] (opens the source)

The 2021 launch named Chrome and Edge and promised Firefox and Safari. On 19 October 2026, neither Edge Add-ons nor Firefox Add-ons listed a Klarna extension; the FAQ archived in April 2026 said iPhone users could enable it in Safari through the Klarna app. The same day, Klarna's own landing pages for the extension redirected to its homepages, though the Chrome extension remained live. [Klarna, Dec 2021] (opens the source)[Microsoft Edge Add-ons, Oct 2026] (opens the source)[Mozilla Add-ons, Oct 2026] (opens the source)[Klarna US (Wayback Machine capture), Apr 2026] (opens the source)[Klarna US, Oct 2026] (opens the source)

Keep three products separate: the payment method you may offer, the app paying shoppers cash back at listed stores, and the browser extension. Deactivating the payment method or uninstalling Klarna's messaging app from Shopify doesn't switch off the extension. The app can list stores without a commercial relationship. [Apple App Store, Oct 2026] (opens the source)[Klarna US, Oct 2026] (opens the source)[Klarna Inc., Aug 2026] (opens the source)

Klarna's page in the extension directory brings the product sources together.

Who pays when it applies a code or cash back?#

You do, when Klarna is in your affiliate programme and credited. Klarna says shoppers' cash back is funded through higher affiliate commission rates; it also sells merchants ads and placements. [Klarna for business, Oct 2026] (opens the source)

Klarna markets itself as a publisher across over 30 networks, charging by action, click or thousand impressions. Its cash back page tells merchants to activate Klarna Affiliate through their network, says the split between commission and shopper cash back varies by market, and offers paid premium app placements. [Klarna for business, Oct 2026] (opens the source)[Klarna for business, Oct 2026] (opens the source)

Its July 2026 network list includes Commission Junction, Impact, Rakuten Advertising and Partnerize. Awin appeared on the older list but isn't on this one; neither list explains why. [Klarna, Jul 2026] (opens the source)[Klarna (Wayback Machine capture), May 2025] (opens the source)

That was 5% of total revenue, up from about $13 million in 2020. [Klarna Group plc, Feb 2026] (opens the source) The filing says a shopper who buys after seeing a merchant's ad in the Klarna app, then pays another way, still generates advertising revenue for Klarna. Your payment-method report won't explain your whole relationship with Klarna.

On 19 October 2026, Klarna advertised up to 3.5% app cash back at Alo Yoga, a Shopify store that doesn't offer Klarna at its own checkout. [Klarna US, Oct 2026] (opens the source) Good American, which does offer Klarna at checkout, showed up to 2%. [Klarna US, Oct 2026] (opens the source) Tatcha showed up to 2%. [Klarna US, Oct 2026] (opens the source) These shopper rewards don't disclose those stores' commission rates.

The BNPL merchant fee is separate: if you offer Klarna at checkout, you pay its merchant fee on those orders. Affiliate commission is additional when Klarna the publisher receives credit. [Klarna Group plc, Feb 2026] (opens the source)

Run your own numbers in the coupon extension cost calculator.

Klarna's own comparison of over 1,000 merchants with network averages claims 1.3x conversion and a 13% AOV rise. [Klarna for business, Oct 2026] (opens the source) Its Booking.com case study reports affiliate-attributed volume from Klarna app traffic up 94% year on year within two months. [Klarna for business, Mar 2026] (opens the source) Attributed volume isn't necessarily additional sales. In a 2023 Haus case study, one DTC brand switched off all its US loyalty partners for seven weeks, and revenue didn't change against comparable countries. Haus sells testing; this wasn't a Klarna result. Your traffic must answer the incrementality question: which sales did the partner add? [Haus, May 2023] (opens the source)

What reaches your store when a shopper pays with its one-time card?#

An ordinary Visa card payment. At stores without Klarna where Klarna enables it, the extension supplies a single-use virtual Visa card for your normal card fields; you receive the card payment and the shopper repays Klarna in instalments. You can't switch it off in Shopify. [Klarna, Mar 2023] (opens the source)[Klarna Group plc, Feb 2026] (opens the source)

The US terms, version 1.1.0, still linked from Klarna's legal hub on 19 October 2026, describe a Visa Commercial Card account for non-integrated stores. It expires if unused within 24 hours, and you can't refund more than the payment amount to it. Klarna reserves the right to block its use at any store. [Klarna, Mar 2023] (opens the source)[Klarna US, Oct 2026] (opens the source) Its US help page says shoppers pay a service fee at stores without Klarna. [Klarna customer service (US), Oct 2026] (opens the source)

Klarna says shoppers check out as if using any other Visa card; it publishes nothing on how the order appears in Shopify. Klarna publishes no US merchant fee or dispute guidance for this card, so don't apply your integrated Klarna payment terms to it. The user terms limit points and one-time cards to websites enabled under Klarna's internal policies; no merchant opt-out or request form is published. [Klarna Group plc, Feb 2026] (opens the source)[Klarna Inc., Aug 2026] (opens the source)

Answer-engine responses recorded on 19 October 2026 suggested deactivating Klarna as a payment method or uninstalling Klarna's messaging app. Neither stops this card, which is built for stores without Klarna. Klarna for Shopify Payments is offered only to stores in certain European countries and the UK; Shopify's list doesn't include the US. [Shopify Help Center, Oct 2026] (opens the source)

In August 2025, Klarna announced Pay in 4 in Chrome's own autofill for eligible US users on purchases over $35, starting later that year; it doesn't say how that reaches stores without Klarna. [Klarna, Aug 2025] (opens the source)

Further viewing: a December 2023 extension walkthrough shows its payment pop-up on a non-integrated store; a November 2025 app tutorial shows the app generating a card for the store's card fields.

Does it leave your partners' clicks alone?#

Klarna said it did. From early February 2025 to at least April 2026, its US extension FAQ said affiliate arrivals wouldn't receive coupon and points prompts. That page now redirects; creators alleged the opposite, and no court decided either way. [Klarna US (Wayback Machine capture), Feb 2025] (opens the source)[Klarna US (Wayback Machine capture), Apr 2026] (opens the source)[Klarna US, Oct 2026] (opens the source)[U.S. District Court, S.D. Ohio, Feb 2025] (opens the source)

The FAQ may still describe the behaviour. But it arrived days before the suit, is no longer published, and isn't repeated in the listing, user terms or privacy notice. Your network needs an enforceable programme rule, rather than a page you can no longer link.

Stand-down means leaving the referring partner's click alone, as networks expect coupon and cashback publishers to do. Klarna's points terms require cookies and say the store calculates points: tracking determines who receives the reward. [Klarna Inc., Aug 2026] (opens the source)

A shopper follows your creator's link, fills a basket, then activates points or applies a code in the prompt. With last-click attribution, credit can move to Klarna; your creator's commission depends on network rules and whether the extension stood down. The cookie stuffing guide explains the tracking question.

What did creators sue it over, and how did it end?#

Creators sued in February 2025, alleging that activation replaced their affiliate tracking with Klarna's. Three claims proceeded in March 2026 on the allegations; the parties filed a stipulation of dismissal on 9 September 2026, with terms not public. Nothing was proven either way; merchants weren't parties. [U.S. District Court, S.D. Ohio, Feb 2025] (opens the source)[U.S. District Court, S.D. Ohio, Mar 2026] (opens the source)[U.S. District Court, S.D. Ohio, via CourtListener, Sep 2026] (opens the source)

Filed on 10 February 2025 in the Southern District of Ohio as Thompson v. Klarna, Inc., No. 2:25-cv-00124, the case is now Ahntourage Media LLC v. Klarna, Inc.: the June 2025 amended complaint named Ahntourage and three other creators as plaintiffs. The original complaint showed a retailer's creator-linked affiliate cookie before activation and a different identifier afterwards, which plaintiffs attributed to Klarna. [U.S. District Court, S.D. Ohio, Feb 2025] (opens the source)[U.S. District Court, S.D. Ohio, via CourtListener, Sep 2026] (opens the source)

On 31 March 2026, Judge Michael H. Watson granted the motion to dismiss in part. Interference with business relationships was dismissed without prejudice; the federal CFAA, interference-with-contract and unjust-enrichment claims continued. [U.S. District Court, S.D. Ohio, Mar 2026] (opens the source)

The case closed on 10 September 2026, following the stipulation filed the day before. The public docket doesn't disclose its terms or whether money changed hands. No court found liability. [U.S. District Court, S.D. Ohio, via CourtListener, Sep 2026] (opens the source) No regulator action or affiliate-network decision about the extension had surfaced by 19 October 2026.

The commission the creators said had moved was money merchants paid, and the moment they described was your checkout. The case's end doesn't answer which Klarna-credited orders your other partners started.

Creators brought similar suits against PayPal Honey, Rakuten and RetailMeNot: see the Rakuten guide, RetailMeNot directory entry and Honey scandal guide.

What can you control on your storefront, at checkout and in your programme?#

Your theme lets you detect and hide storefront prompts; at checkout, your control is which codes work. Your affiliate programme decides Klarna's approval and terms. Klarna controls its extension and one-time card.

Chrome content scripts have separate JavaScript worlds but share the page's DOM, the page structure. Shopify checkout UI extensions run in a sandbox without checkout HTML access; advanced checkout customisation is Plus only. [Chrome for Developers, Oct 2026] (opens the source)[Shopify developer docs, Jul 2026] (opens the source)[Shopify Help Center, Oct 2026] (opens the source)

The Discount Function API sees entered codes and can reject them with a message only when backed by an automatic discount. Public App Store apps with Functions work on any plan; custom apps with Functions need Plus. [Shopify developer docs, Oct 2026] (opens the source)[Shopify.dev, Oct 2026] (opens the source) There's no official way to hide the discount field: Shopify staff said there was no timeline in October 2024. [Shopify Developer Community, Oct 2024] (opens the source)

Without Klarna in your programme, directly or through a network on its list such as Skimlinks or Viglink/Sovrn, you pay it no affiliate commission. Its extension can still test web-sourced codes and offer its card. No merchant opt-out is published; the listing gives only the developer's email address and phone number as contacts. [Chrome Web Store, Oct 2026] (opens the source) See storefront and checkout controls.

What can you do without an app?#

Start with your codes, programme approvals and a browser test. Assign owners before your freeze.

1. See which of your codes it can find. Your discount owner can run the free code check, which asks Honey, Capital One Shopping, Coupert, Rakuten and major voucher sites without installing anything. Klarna publishes no list; this shows what's loose on the web, where its old extension page said it looked. The directory page collects its sources. The catch: a listing doesn't tell you which orders used a code.

2. Tighten the codes it can find. Your discount owner moves private offers to unique or single-use codes before your code freeze. Shopify allows 20,000,000 unique codes per store; bulk creation uses apps or the Admin API, up to 250 per call. Set shared-code usage limits and end dates. [Shopify Help Center, Oct 2026] (opens the source)[Shopify.dev, Oct 2026] (opens the source)[Shopify Help Center, Oct 2026] (opens the source) Follow code leak controls and unique versus shared codes. The catch: creators can't read unique codes aloud in videos.

3. Find it in each affiliate programme. Your affiliate manager searches each publisher list: Klarna's July 2026 network list is the starting point, and it includes sub-networks such as Skimlinks and Viglink/Sovrn; Partnerize lists username klarna. [Klarna, Jul 2026] (opens the source)[Partnerize, Oct 2023] (opens the source) Check last quarter's payments, earlier partner clicks, stand-down, code-only crediting and capped rates in your affiliate agreement terms. An affiliate publisher earns referral commission; Klarna's Creator Platform lists its own publisher IDs; Klarna doesn't say they identify extension traffic. [Klarna for business, Oct 2026] (opens the source) The catch: removing approval stops commission, not the extension or card.

4. Ask your network about credit. Your affiliate manager asks how competing clicks are credited, whether Klarna must stand down, and whether the network can show your Klarna-credited order paths. The catch: Klarna's stand-down statement is no longer live, so put stand-down in your terms.

5. Watch your own checkout. Your developer installs the extension in a clean Chrome profile, follows a test affiliate link and fills a basket. Record prompts, cookie changes after activation and whether the card is offered. The catch: one browser isn't every shopper, and Klarna's FAQ said points and the card needed a Klarna login. [Klarna US (Wayback Machine capture), Apr 2026] (opens the source)

6. Measure which orders it starts. Your growth lead runs a holdout: randomly selected eligible shoppers keep the existing experience. The how-to guides cover setup. Klarna's comparison and the independent loyalty switch-off gave different answers; test your traffic. The catch: small stores need weeks, so November testing won't read before Cyber Monday.

For other extensions, read the Honey, Capital One Shopping, Coupert and Rakuten guides, or coupon extensions 101.

How Benson handles the extension on your store#

Benson measures extension sessions and gives your team storefront rules, code policies and affiliate evidence.

Observe on Free. Benson shows which coupon and cashback extensions your shoppers run, Klarna included, in which sessions, and what it would hide. Observe mode changes nothing on your store. The Checkout rules page lists codes used most in coupon-extension sessions; code watch shows whether a leaked code is contained, replaced or back again, and flags a replacement that starts spreading too.

Hide storefront prompts on Stop and above. Block covers home, product, collection, search and cart pages, plus the cart drawer. Rules support schedule, country, source, device and page, with a holdout.

Control codes on Stop and above. With the strict code policy, only allowlisted codes work in coupon-extension sessions; others receive a short message instead of a discount. Customers without an extension can still type the code you sent. On Shopify, no app can change what an extension shows inside checkout, so protection there works on codes.

Measure stand-down in beta. Under Affiliates → Integrity, the beta check Extension didn't stand down opens a Stand-down page that scores each extension, Klarna included, on each network your partners use. The score is the share of partner-click arrivals where the click stayed unchanged with the extension present or installed, with a likely range. It appears from 20 eligible sessions. Three replaced clicks for an extension on a network in 30 days open a case with sessions, orders, commission at stake and a compliance evidence pack.

Free shows totals; paid plans show each extension's score and a 12-week trend. Like every integrity check, it reads storefront pages, not inside Shopify checkout. Installed-extension coverage is desktop Chrome only, in sessions your consent settings permit Benson to track.

Follow changes in credit. Benson records arriving affiliate IDs, click IDs or UTM sources, changes after the cart, the extension detected in that session, and estimated commission moved at your rates. Extension took the click opens a case once three or more sessions in 30 days show a partner's click replaced while a coupon or cashback extension was on the page. Checks and counts are free; cases, evidence, printable packs and CSVs with your order numbers need Stop or above. Read the integrity checks and affiliate integrity reading path.

Review the deal. Record Klarna's agreement and, using attribution integrity on Stop and above, read how often it joins after the cart. The partner deal playbook takes you through keep, renegotiate or cut. Every control can run against a holdout on your store.

Film 03 / 09You have a deal with an extensionWatch1:11

Add Benson from the Shopify App Store and leave it in observe mode through a normal week before peak.

Sources#

• Chrome Web Store: Klarna browser extension listing (Oct 2026)
• Klarna Inc.: One-time Card Service Terms, US (Mar 2023)
• Internet Archive: Klarna browser extension page, capture of 15 April 2026
• TechCrunch: Klarna launches browser extension with payments and coupons (Dec 2021)
• Klarna: Browser extension launch announcement (Dec 2021)
• Klarna Inc.: US privacy policy (Oct 2026)
• Microsoft Edge Add-ons: Klarna search results (Oct 2026)
• Mozilla Add-ons: Klarna search results (Oct 2026)
• Klarna US: Browser extension page, now a redirect (Oct 2026)
• Apple App Store: Klarna app, US listing (Oct 2026)
• Klarna US: Cash back information (Oct 2026)
• Klarna Inc.: User Terms for Klarna Shopping Service (Aug 2026)
• Klarna for business: Cash back programme (Oct 2026)
• Klarna for business: Affiliate content (Oct 2026)
• Klarna: Affiliate Networks (Jul 2026)
• Internet Archive: Klarna affiliate network list (May 2025)
• Klarna Group plc: Annual report on Form 20-F for 2025 (Feb 2026)
• Klarna US: Pay with Klarna at Alo Yoga (Oct 2026)
• Klarna US: Pay with Klarna at Good American (Oct 2026)
• Klarna US: Pay with Klarna at Tatcha (Oct 2026)
• impact.com: The affiliate benchmark for 2025 (Feb 2026)
• Shopify: Affiliate commission guide (May 2026)
• Klarna for business: Booking.com affiliate growth case study (Mar 2026)
• Haus: Affiliate on/off test reveals the incrementality of loyalty sites for global DTC brand (May 2023)
• Klarna US: Terms and Conditions legal hub (Oct 2026)
• Klarna customer service: What is a one-time card and how does it work? (Oct 2026)
• Shopify Help Center: Klarna for Shopify Payments (Oct 2026)
• Klarna: Pay in 4 in Chrome autofill announcement (Aug 2025)
• Internet Archive: Klarna browser extension page, capture of 3 February 2025
• U.S. District Court, S.D. Ohio: Thompson v. Klarna, complaint (Feb 2025)
• Internet Archive: Klarna browser extension page, capture of 1 March 2025
• U.S. District Court, S.D. Ohio: Ahntourage Media v. Klarna, opinion and order on the motion to dismiss (Mar 2026)
• U.S. District Court, S.D. Ohio: Ahntourage Media v. Klarna docket (Sep 2026)
• Chrome for Developers: Content scripts (Oct 2026)
• Shopify.dev: Checkout UI extensions (Jul 2026)
• Shopify Help Center: Checkout and accounts page customisation (Oct 2026)
• Shopify.dev: Discount Function API (Oct 2026)
• Shopify.dev: About Shopify Functions (Oct 2026)
• Shopify Developer Community: Ability to hide discount field (Oct 2024)
• Shopify Help Center: Discount codes (Oct 2026)
• Shopify.dev: Bulk discount redeem codes (Oct 2026)
• Shopify Help Center: Amount off discounts (Oct 2026)
• Partnerize: Klarna partner directory entry (Oct 2023)
• Klarna for business: Creator Platform (Oct 2026)
• Apple Community: Klarna pop-up cannot be removed in Mac Chrome (Nov 2024)
• Linux Mint Forums: How to get rid of Klarna (Oct 2023)
• The Baby's Booty: Klarna payment walkthrough (Dec 2023)
• MK Loves Tech: Klarna app and one-time card tutorial (Nov 2025)
• Benson glossary: Coupon extension
• Benson glossary: Cashback extension
• Benson glossary: Browser extension permissions
• Benson directory: Klarna
• Benson calculator: Coupon extension cost
• Benson glossary: Incrementality
• Benson glossary: Stand-down
• Benson glossary: Last-click attribution
• Benson guide: Cookie stuffing
• Benson guide: What the Rakuten extension does on your store
• Benson directory: RetailMeNot
• Benson guide: What the Honey scandal cost merchants
• Benson guide: Storefront and checkout controls
• Benson tool: Code check
• Benson glossary: Code freeze
• Benson guide: Stopping discount code leaks
• Benson guide: Unique versus shared discount codes
• Benson guide: Affiliate agreement terms
• Benson glossary: Affiliate publisher
• Benson guide: Holdout measurement for coupon controls
• Benson guides: How to
• Benson guide: How to block Honey on your Shopify store
• Benson guide: What the Capital One Shopping extension does on your store
• Benson guide: What the Coupert extension does on your store
• Benson learn track: Coupon extensions 101
• Benson docs: Affiliate integrity
• Benson learn track: Affiliate integrity
• Benson playbook: Partner deal
• Shopify App Store: Benson