Learn how Fortune 500 brands are using identity resolution in 2025
Instant access • No spam • Privacy-first insights
September 18, 2025
The following is a practical, no‑nonsense guide for eCommerce brands, agencies, and marketers preparing for iOS 26’s new tracking constraints.
This article is brought to you as a collaboration between Opensend and our attribution partner, Fueled. Sean Larkin, Fueled’s CEO, is the primary author.
In short, no one exactly knows all the details (and there’s a lot of well-intentioned misinformation out there) – but Apple is clearly taking dramatic steps to enhance privacy in iOS 26 by limiting fingerprinting and likely turning on default Safari privacy settings that strip tracking parameters from the website URLs that you visit.
These changes, particularly the removal of tracking parameters (i.e., click IDs from ads and marketing platforms), could have a significantly negative impact on ad performance and measurement within retention marketing platforms.
Stripping these click IDs will make it much more difficult for advertising platform algorithms to optimize campaign performance.
Here are the changes that we think we know:
To address this likely signal loss, marketers will need to become more savvy in how they implement tracking pixels and Conversion APIs. Brands will have to adopt advanced best practices for pixel tracking, and strongly consider leveraging more robust 3rd-party tracking solutions (like Opensend and Fueled) to get around these constraints.
(Specific recommendations follow.)
[Short-History]
Apple is pushing privacy features that could significantly dampen signal into advertising platforms, like Google and Meta Ads, with the release of iOS 26.In iOS 26, Advanced Fingerprinting Protection will extend to all browsing by default (not just Private Browsing).
Apple’s own press coverage has reinforced the “default‑on” direction for AFP in iOS 26.
Link Tracking Protection (LTP) from iOS 17 will continue to strip “known” tracking parameters in Mail, Messages, and Private Browsing. UTM parameters will generally remain.
While we don’t know for sure (Apple won’t say, and they change details late), the big concern is that Apple will expand this parameter stripping beyond those iOS 17 contexts (Mail, Messages, Private) to all regular Safari browsing in a way that broadly removes advertising tracking parameters (like Google’s gclid and Meta’s fbclid) before a website loads and tracking pixels have a chance to run.
In other words: The big concern with the release of iOS 26 is that it will strip critical Click IDs from all Safari browser sessions by default. Some blogs say “yes, this is definitely going to happen”, while others are hedging. This is an area to watch and test – and to treat third‑party claims as provisional unless you can reproduce them in your own flows.
Examples of informed (yet still speculative) takes:
When Link Tracking Protection (LTP) removes click IDs like gclid, fbclid, or msclkid, fewer sessions attach cleanly to an ad click. The symptoms: lower reported conversions in platform dashboards, noisier CPA/ROAS, and slower bid learning.
Many platforms seed website audiences from click-sourced identifiers or cookie-based tags. With fewer usable click IDs and shorter-lived browser storage, match rates drop, audience sizes taper, and prospecting/retargeting frequency becomes harder to control. Expect more budget to shift to broad targeting unless server-side signals backfill the gaps.
Within a single advertising channel, like Meta or Google Ads, attribution will look better for browsers/devices that do not strip these identifiers—shifting ad budgets automatically towards these audiences, even if they are not the actual highest performers.
Between advertising channels, performance will appear stronger for those channels that provide alternative attribution modeling that doesn’t rely solely on click IDs. Without advanced mixed media modeling, this could drive teams to mis-allocate advertising budget between paid channels.
Email/SMS journeys sourced from ads will be harder to tie back to the original click on iOS. Platforms like Klaviyo will still show revenue, but ad platforms may under-credit the initial acquisition. Without server-side joins (order ID ↔ hashed email/phone ↔ campaign), LTV by channel will skew low.
[get-your-personas]
With fewer attributed conversions, automated bidding will under-spend or chase the wrong inventory. Server-side events and EC/Enhanced Conversions restore volume and quality so Smart Bidding, Advantage+ Shopping, and similar systems keep learning.
Smaller audiences and weaker event signals elongate test cycles. Expect more reliance on holdouts, geo splits, or modeled outcomes to validate winners.
Reported ROAS may fall while revenue stays flat. The right narrative is “signal loss,” not “channel collapse.” Durable fixes (EC/CAPI/server-side tracking solutions) should precede budget cuts.
Google Analytics and other click-based measurement platforms will experience similar signal loss in reporting attribution. Mixed Media Modeling (MMM) will continue to become more and more important — as these tools do not rely on click data to evaluate channel attribution.
Consistently work to improve event quality match scores in your advertising platforms by finding ways to collect and send 1st-party identifiers to your advertising platforms.
Expect this share to decline on iOS; the goal is stable total conversions after server-side uplifts.
Increases in modeled conversions are normal with more privacy; just ensure server-side inputs are maximized.
Use consistent lookback windows and watch for recovery after deploying Enhanced Conversion optimization and Conversion API strategies.
Net-net: the play isn’t to outsmart Apple; it’s to starve the brittleness out of the stack. 1st-party data, Enhanced Conversions, server-side CAPIs, and ID graph implementations turn a scary change into a survivable—often net-positive—upgrade.
It might be obvious, but you should continue to leverage click IDs and pixel-based tracking – despite all of these changes. While it’s likely, at some point, that other browsers will follow suit with Safari 26, at least for now, click IDs are critical and continue to function for most browsers.
Many advertising platforms allow you to send hashed customer data as personal identifiers when tracking conversions – most notably Google Ads. Make sure that you have Enhanced Conversions configured correctly, as these identifiers help advertising platforms stitch together ad impressions to conversions, even when click IDs are stripped.
Advertising platforms such as Meta and TikTok allow you to send attribution events server-side in addition to sending these events via their client-side JavaScript libraries. Make sure that these Conversion API (CAPI) configurations are healthy, collecting all available hashed personal identifiers, and deduplicating client-side and server-side events appropriately.
Platforms like Fueled and Opensend can enrich your signal into Conversion APIs by storing persistent identifiers that help improve customer match rates into platforms like Meta and TikTok across sessions and devices. These tools are becoming critical to brands’ success as click IDs are stripped from the browser.
iOS 26’s impact on Klaviyo link tracking is a gray area. Some guides on the Web suggest that Klaviyo click IDs are not impacted by changes with iOS 17 or 26. However, when viewing a site in iOS 17 in privacy mode, Apple commonly reports that Klaviyo trackers are disabled.
Regardless, to boost signal into Klaviyo, we strongly recommend that you:
We aren’t going to lie to you, losing Facebook Click ID (fbclid) into Meta because of iOS 26 changes is a significant loss.
Most advertisers run dozens, if not hundreds, of campaigns and ads simultaneously, and Meta’s click IDs are the only truly deterministic way to attribute conversions to different advertising experiences.
That said, Meta’s Conversions API is the most robust solution on the planet for matching shoppers and their conversions to ad experiences.
We recommend a few strategies and tools to boost signal into Meta in an iOS 26 world.
Like Meta’s click ID, Google’s click ID (gclid) is a primary target of iOS 26 tracking parameter stripping – making the following solutions incredibly important moving forward.
With Google Enhanced Conversions, you can send hashed identifiers on your conversion events, most notably lead form submissions and purchases.
This allows you to attribute conversions where a Click ID might have been stripped – as well as understand view-through conversions, which are particularly key to YouTube advertising.
We frequently see brands make two mistakes with Google Enhanced Conversions, particularly on Shopify.
The following is a Shopify Custom Pixel recipe that we’ve found to be highly effective at optimizing Google Enhanced Conversions:
code box
One of the easiest ways to survive iOS 26’s stripping of click IDs is to stop depending on the browser to hang onto them at all. Instead, capture them yourself, tie them to orders, and send them back later via Offline Conversion Tracking (OCI) in Google Ads.
Why this matters:
The “ghost GCLID” approach:
Because Apple’s Link Tracking Protection targets known tracking parameters (gclid, fbclid, msclkid…), a common resilience move is to mirror the value into a differently named parameter. Apple doesn’t strip arbitrary names (yet), so you get to keep it.
Example:
How to set it up in Google Ads
1. Go to Campaign → Settings → Tracking template.
Add a Final URL Suffix to duplicate the gclid into your own parameter. For example:
code box
2. Now your ad click URLs will look like https://example.com/?gclid=XYZ&acid=XYZ.
3. On your site, write a tiny script to capture acid and store it in a 1st-party cookie or your database (just like you would with gclid).
code box
4. Tie that acid to the order in your backend (e.g., store it on the customer/session record).
5. When you report the conversion back via the Google Ads API or CSV upload, set the gclid field equal to the stored acid value. Google doesn’t care that it didn’t arrive in the landing page URL as gclid—as long as you hand it a valid click ID at upload time, it works.
Uploading an offline conversion (API pseudo-example)
code box
The punchline
iOS will likely begin stripping TikTok click IDs by default as well. Optimizing your Pixel and TikTok API integrations for TikTok Ads for iOS 26 changes is almost identical to the optimization strategy we listed above for Meta Pixel/CAPI.
Microsoft/Bing Ads’ click ID (msclkid) is another primary target of iOS 26’s privacy features. Fortunately, in February 2024, Microsoft Ads released its own Enhanced Conversions framework, similar to Google Ads’ solution. Microsoft’s Enhanced Conversions are much simpler than Google’s, and only support email and phone number as enhanced identifiers.
The following is a Shopify Custom Pixel recipe that we’ve found to be highly effective at optimizing Microsoft Ads Enhanced Conversions:
code box
iOS 26 is likely to strip Microsoft/Bing Ads’ click ID (msclkid) by default as well. However, the good news is that Microsoft gives us {msclkid} as a template token for your campaign URLs, which means we can clone it into another parameter name that Apple doesn’t recognize. Think of it like a spare house key hidden under the doormat.
Unlike Google’s gclid, Microsoft makes it easy for us to use this cloned click ID to set its campaign/click ID cookie – allowing us to capture/restore this identifier when msclkid is stripped by iOS 26.
Here’s how to set it up:
NOTE: This is extremely experimental - and it is very possible that Microsoft will change the strategy it uses to set these cookies in the near future. Please use only at your own risk. We provide no guarantee that this will work consistently, nor do we provide any sort of warranty for this potential solution.
Step 1: Add a Ghost Parameter in Microsoft Ads
Go into your campaign (or account-level) settings in Microsoft Ads and edit the Tracking Template.
Add this:
msclkid={msclkid}&bclid={msclkid}
So your landing page URLs will now look like:
https://www.example.com/?msclkid=123abc456&bclid=123abc456
Step 2: Capture and Restore the Cookie
On your site, drop a small script that:
code box
This guarantees that even if Safari nukes msclkid, the twin bclid will survive, and you’ll still set the correct cookie.
Step 3: Verify It’s Working
The Bing UET tag automatically reads this cookie, so your conversions continue to tie back to the right clicks.
Why This Works
Reference
Official Microsoft Ads documentation on msclkid: https://help.ads.microsoft.com/#apex/ads/en/60178/-1
As of September 14th, 2025, it is unclear to us if iOS 26 will strip The Trade Desk’s click IDs – though it would seem likely, given that The Trade Desk is a major programmatic ads platform.
Fortunately, The Trade Desk recently released its own Conversions API – and Fueled is slated to be able to offer this solution to its customers in Q4 2025. Interestingly, our solution will include UID2 identification as well, providing stronger identification than The Trade Desk click IDs alone.
References
In navigating this cat and mouse game between browser technologies and advertising platforms, you need to be mindful about compliance and build trust with your customers through transparency.
Apple will keep tightening. They also keep details intentionally squishy until the last minute.
Advertisers that keep up with these changes will continue to win.
The most successful advertisers will lean on attribution tracking partners and technology providers to help them stay on top of these best practices auto-magically, so that they can stay focused on brand, creative, and high-level strategy.
Our commitment to you is to continue to provide you with as much information on these changes as possible – and to share tactics that boost signal in a privacy-first world.
Treat as informed commentary, not gospel.
September 18, 2025
.svg)
