Marketing Digital
Safari blocks email-based tracking: what small online stores should do
Since iOS 27 shipped in mid-September 2026, Safari cuts off the vendors that grab the email address you type on a website to follow you elsewhere. For a small online store, the job isn't to work around the block. It's to check which tools run on its forms and to lean on the data customers hand over directly.
Put simply: if part of your advertising depends on tracking people from one site to the next, some of your iPhone, iPad and Mac visitors just went dark for those tools. If it depends on your own customer relationships, you lose almost nothing. Here's the diagnosis and the prescription.
What exactly is Apple blocking in Safari?
Apple blocks the servers of "identity resolution" companies, not online stores or newsletter tools. The block works at the domain level, in Safari and WebKit (the engine behind Safari), on iOS, iPadOS, macOS and visionOS 27.
Here's how identity resolution works, according to the post on the WebKit blog published in October 2026: when you log in to a site or sign up for its newsletter, an invisible third party on the page grabs your email address, sends it to its servers, ties it to a permanent tracking ID and sends that ID back to the site. The ID is then used to piece together your browsing and target you with ads on other sites. Apple doesn't mince words: these companies "are not themselves login providers or newsletter services, they're just there to track you."
One point matters a lot for merchants: Apple states that first-party personalization is not tracking. Recommending a product to a logged-in customer, sending your newsletter, measuring your store's sales: none of that is targeted.
Why is this happening now?
Because third-party cookies stopped being enough to follow people around, and email addresses took their place. Safari launched Intelligent Tracking Prevention (ITP) in 2017, then fully blocked cross-site cookies in 2020.
Since then, WebKit says, "the tracking industry has not sat idle." It built so-called "post-cookie" methods, identity resolution among them. An email address is the perfect identifier for that: people keep it for years, type it everywhere, and it links their devices together. That's exactly what Apple wants to break.
The rollout was quiet. As Blog du Modérateur reported on October 22, 2026, ad requests had been failing on updated iPhones since iOS 27 came out, and the companies involved waited more than a month for an official explanation.
How much does the block cost online advertising?
Not much on average so far, but noticeably on updated devices. The first published figures cover website publishers, not online stores yet.
According to Digiday on October 12, 2026, among clients of Aditude, a company that helps publishers sell their ad space, Safari on iPhones and iPads accounts for 11.7% of ads shown and 11.4% of ad revenue. On devices running the new version, eCPM (revenue per thousand ads shown) fell 10.5%. With only about 8% of users updated at the time, Aditude put the overall hit at about 1% of revenue.
That number will climb as updates spread. And history calls for caution: after Apple's previous crackdown, App Tracking Transparency for apps in 2021, Meta estimated it would cost around $10 billion in a single year, Digiday notes.
Is my store affected?
Probably indirectly. A small online store rarely hires an identity resolution service itself, but its ad tools, its agency or a script someone added "to improve targeting" may do it on its behalf.
Apple doesn't publish the list of blocked domains. The names going around come from a report filed on September 21, 2026 on WebKit's public bug tracker by an engineer at The Trade Desk, an ad-buying platform, according to Blog du Modérateur. The Trade Desk's main ad domain was in fact blocked, then removed from the list in a test release, with a fix expected for users at the end of October.
Symptoms to watch for on your store:
- a drop in conversions credited to your campaigns, concentrated on Safari and iOS visitors, while your actual sales hold steady;
- retargeting audiences shrinking for no obvious reason;
- a widening gap between the sales your store records and the sales your ad platforms claim.
If you see all three at once, your marketing isn't sick. Your measuring instrument is.
What should you actually do, without trying to work around it?
Take back control of what runs on your site and build on your direct relationship with customers. Working around a block made in the name of privacy is a technical dead end, and a bad signal to send your customers.
Inventory the scripts on your forms. Login page, account creation, newsletter signup, checkout: ask your agency or developer for the list of every third-party script loaded on those pages and what each one does. A tool nobody can explain has no business sitting next to an email field.
Measure with your own numbers first. Your store's back office knows your orders, carts and customers. That's your baseline. Ad platform dashboards are estimates to check against it, not the other way around.
Take care of your first-party data. That's the data customers give you themselves: customer accounts, purchase history, preferences, newsletter signups. It isn't affected by the block, and it's gold if you use it well: personalized recommendations on your site, useful emails, a loyalty program.
Give people a real reason to sign up. A newsletter that delivers something (tips, early access, guides to using your products) builds an audience you own, whatever the browser.
Be clear about how you use email addresses. Explain in plain words, right where people type it, what you'll do with their email. For GDPR compliance, have your data protection officer or legal adviser review your practices.
My takeaways
- Cross-site tracking keeps shrinking, and Apple's move won't be reversed. Building growth on it means building on sand.
- The diagnosis starts with your forms: list the third-party scripts on pages where customers enter their email, and remove any without a clear purpose.
- Your back office is your thermometer: every month, compare real sales with the conversions your campaigns claim, separating Safari from other browsers.
- Invest in direct relationships: customer accounts, a useful newsletter, loyalty. It's the one channel nobody can cut off.
- Stay transparent: customers who understand why you ask for their email are more willing to give it.
Safari's block isn't bad news for merchants who know their customers. It's mostly bad news for the tools that were tracking those customers behind their backs.
Frequently asked questions
What is the identity resolution that Safari now blocks?
It's an ad-tracking method. An invisible third party grabs the email address typed on a website, during login or a newsletter signup, and ties it to a permanent tracking ID. That ID is used to follow the person across sites and target them with ads. Since iOS, iPadOS, macOS and visionOS 27, Safari blocks network access to these vendors' servers.
Does Safari's block stop me from sending my newsletter?
No. Apple targets companies that collect addresses to track people, not newsletter services or login tools. Apple also states that first-party personalization is not tracking. You can keep collecting signups, sending your emails and recommending products to logged-in customers as before.
How can I tell whether my ad campaigns are affected?
Compare the real sales your store records with the conversions your ad platforms claim, separating Safari and iOS visitors from everyone else. A drop in conversions credited on Safari without a drop in sales, or retargeting audiences that shrink, point to a measurement problem rather than a business problem.
Should I try to work around the block?
No. The block works at the domain level, so it's hard to get around technically, and trying would send customers the wrong signal about their privacy. You're better off inventorying the third-party scripts on your forms, measuring with your own numbers and growing the data customers share with you directly.
Sources
- Blocking Identity Resolution Infrastructure · WebKit (Apple), 2026-10-19
- Pistage publicitaire : pourquoi le nouveau blocage de Safari inquiète l'adtech · Blog du Modérateur, 2026-10-22
- Ad industry tallies early losses from Apple's Safari tracking block · Digiday, 2026-10-12