05 September 2025

iOS 26: Apple’s latest privacy salvo and what it means for advertisers

Disclaimer: The Louder team has conducted tests based on the iOS 26 Beta 5 version currently available. Once the stable release is officially launched, additional changes may emerge. Please check back with the Louder team after Apple’s official release for any updates on observed changes, their impact, and our resulting recommendations.

In summary

• What’s happening: Apple’s iOS 26 introduces expanded Link Tracking Protection and fingerprinting safeguards, stripping click IDs and masking identifiers.
• Why it matters: These changes disrupt attribution and audience targeting, directly impacting how advertisers measure campaign performance across the likes of Google, Meta and other major advertising platforms.
• How to respond: Pivot towards first-party data, server-side tracking, and blended measurement models like Media Mix Modelling (MMM) and incrementality testing to future-proof your marketing.

Apple tightens the privacy noose with iOS 26 update

Apple’s iOS 26 update is more than a routine refresh. It represents another decisive step in Apple’s long-running campaign to position itself as the champion of user privacy, and in the process, disrupt the advertising models of Google, Meta, and anyone else who relies on granular tracking.

While many consumers think Chrome or Edge behave the same across devices, all browsers on iOS are built on WebKit, Apple’s browser engine. That means Apple holds a unique level of control over how web tracking works on iPhones, regardless of the app “skin” you use.

From Intelligent Tracking Protection (ITP) introduced in 2017, to the App Tracking Transparency (ATT) update in 2021, and now the introduction of Link Tracking and Fingerprinting Protection in iOS 26, Apple has continually tightened the screws on digital tracking. What began with limiting cookies has evolved into stripping many click IDs, masking emails, and injecting “noisy signals” to disrupt fingerprinting technologies.

Early testing suggests that in most instances, gclid, fbclid, dclid, and similar click IDs are being removed, while aggregate identifiers like wbraid and gBraid remain unaffected across all scenarios tested so far.

Apple’s ITP has gone through roughly 20 iterations over time, with each one tightening restrictions on tagging and tracking, disrupting existing business models along the way. iOS 26 continues to build on prior updates in the same way.

Apple privacy updates: Key milestones

Note: This is a summary of the most significant updates to date, not a complete list of every granular change.

Year	Update	Biggest impact
2017	Intelligent Tracking Protection (ITP)	Limited third-party cookies in Safari
2021	App Tracking Transparency (ATT)	Severely impacted Facebook Audience Network
2023	Link Tracking Protection (iOS 17)	Initially applied to Mail and Messages only
2024/25	iOS 26 Update	Expanded LTP, fingerprinting protection, email masking

The big changes in iOS 26

Expanded Link Tracking Protection

Previously confined to Private Browsing, Mail, and Messages, LTP in iOS 26 will apply to all Safari sessions. Identifiers such as Google’s gclid and Meta’s fbclid are said to be stripped at scale, weakening attribution models that rely on click IDs.

If advertisers want to understand the impact of their media spend, they rely heavily on click tracking, which is why Apple’s latest changes are such a major development.

Independent Louder tests of the iOS 26 beta show:

• UTM parameters (utm_source, utm_campaign) appear to survive across all scenarios tested so far, including both standard and private browsing modes.
• Click IDs from major platforms, such as Google (gclid, dclid), Meta (fbclid), Bing (MSCLKID), and TikTok (TTCLID), are the ones most impacted, being stripped in Private Mode, in Messages from third-party senders, and increasingly across Safari sessions.
• Mail app behaviour remains mixed. UTMs continue to pass through, but open-rate level tracking remains heavily limited.

Advanced fingerprinting protection

Safari will now deliberately inject “noise” into APIs commonly used for fingerprinting, including screen resolution, audio, canvas, and even Apple Pay signals. The values returned by these APIs are slightly altered each time they are queried, so they never return exactly the same information twice. Because fingerprinting relies on consistent, fixed device attributes to build a persistent ID, this randomisation makes it extremely difficult to generate a stable fingerprint for cross-device matching or retargeting.

Noise injection essentially breaks the link between attributes and identity. Advertisers have traditionally relied on techniques like cross-device matching and retargeting to join user behaviour across different environments. By randomising key attributes, Apple makes these techniques far less reliable, and in some cases, unusable.

You can test this yourself using the Cover Your Tracks tool from the Electronic Frontier Foundation, which shows what information your browser shares and how easily it can be used to fingerprint your device.

Email relay and masking

Apple’s “Hide My Email” feature allows users to generate random Apple-managed email addresses that forward to their real inbox. Traditionally, this breaks the connection platforms like Meta and Google rely on to match email addresses across datasets. For example, linking ad impressions to conversions via a user’s real email.

However, this isn’t new. “Hide My Email” launched in 2021, and Apple hasn’t made major updates to this feature in iOS 26. The email-specific changes, soon to be launched, focus more on blocking visibility into open rates, click rates, and other engagement signals in the Mail app. A much bigger deal for businesses running email campaigns than for audience matching workflows.

Apple’s strategic positioning

By tightening privacy controls, Apple is reshaping how the entire advertising ecosystem competes.

Apple has taken a systematic, whole-of-category approach to position itself as the leader in privacy and security. At the same time it continues to limit the ability of Google, Facebook, and other advertising platforms to target users effectively.

Instead, Apple funnels users into its own monetisable ecosystem, App Store, Apple News, Apple subscriptions, while weakening rivals’ ad-based revenue streams.

Industry-wide impact

This isn’t just about Google and Meta.

• Demand side (advertisers): Campaign measurement reliant on click IDs will lose fidelity.
• Supply side (publishers): Audience creation becomes harder as third-party identifiers disappear.
• Tech platforms: Workarounds like Facebook’s localhost tracking are increasingly being shut down.

The changes affect every part of the ecosystem, demand side, server side, and supply side alike.

Louder’s recommendations

Apple’s iOS privacy updates aren’t a one-off, they’re a long-term direction. Louder recommends that marketers future-proof attribution and measurement by:

• Strengthen first-party data strategies - Collect consented customer data directly and integrate CRM systems into attribution flows.
• Diversify measurement - Adopt server-side tracking, which is more resilient to browser changes and blend attribution with incrementality testing (e.g., holdout tests) and use Media Mix Modelling (MMM) for holistic performance views.
• Adapt attribution models - Move away from over reliance on click IDs. Explore privacy-centric solutions like Meta’s Aggregated Event Measurement and leveraging user provided data where applicable.
• Deploy parallel tagging - Run manual UTMs alongside auto-tagging across all campaigns to create a measurement safety net if Apple’s changes strip certain parameters. Ensure your web servers accept all relevant parameters so data isn’t truncated or blocked, and validate tagging across Mail, Messages, and safari environments.
• Get comfortable with some degree of ambiguity in measurability. This may include exploring modelled data solutions in place of directly measurable conversions. For GA this requires the use of consent mode signals, which isn’t yet a regulatory requirement in the local market, but something we encourage clients to look at ahead of time.

Allowlisted parameters and new aggregate IDs

Marketers/web teams should ensure their web servers and analytics setups accept all industry standard tracking parameters to prevent tracking loss. This includes Google’s newly added aggregate identifiers, gad_source, and gad_campaignid, alongside the following common tracking parameters such as: gbraid, dclid, gclsrc, gclid, wbraid, utm_source, utm_content, utm_id, utm_medium, utm_campaign, utm_term, utm_source_platform, utm_creative_format, utm_marketing_tactic and srsltid.

Related articles

• Apple ITP targets HTTP cookies with 7 day cap
• ITP and iOS14: Apple moves to shake up end user privacy across the iOS ecosystem
• Safari tightens the ITP screws again
• Apple announce major Safari privacy changes

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