Wake Lock API case study: 300% increase in purchase intent indicators on BettyCrocker.com

Recipe pages have a specific, physical failure mode that has nothing to do with page speed: you prop the phone against a mixing bowl, your hands are covered in flour, the screen dims after 30 seconds, and now the page is gone. No amount of Core Web Vitals work fixes that. The Screen Wake Lock API does, in about fifteen lines of JavaScript, and this BettyCrocker case study is the clearest example of what happens when a site removes a friction point that everyone had simply accepted.

Below is the implementation detail: how the API behaves, the release rule that breaks naive implementations, where it can be blocked, and how to measure the outcome honestly rather than reusing someone else's headline number.

The API surface, in full

The whole feature is one promise returning method and a small object. Requesting the lock returns a WakeLockSentinel, which is your handle for releasing it and for observing when the browser released it for you.

Two environment conditions block the request before your code is at fault. The page must be a secure context, meaning HTTPS or localhost. And Permissions Policy must allow it: the feature is gated by the screen-wake-lock policy, so a page embedded in an iframe needs allow="screen-wake-lock" on that iframe, and a site sending a restrictive Permissions-Policy response header has to include the feature explicitly.

The release rule that breaks naive implementations

The browser releases the wake lock automatically whenever the document stops being visible: the user switches apps to check a message, answers a call, or locks the phone. When they come back, the lock is gone and the screen starts dimming again, even though your toggle still says the feature is on. Users read that as the feature being broken, because from their side it is.

The fix is the visibilitychange listener shown in the diagram: when the document becomes visible again and the user has not turned the feature off, request the lock again. Two details make the difference between a working implementation and a flickering one. Track intent separately from the sentinel, so you know whether the user wants the screen kept awake independently of whether you currently hold a lock. And drive the toggle's visual state from the release event, so it always tells the truth about the current state. The toggle also has to respond instantly when tapped, which is an interaction responsiveness question covered in our note on INP.

When it is the right feature, and when it is not

Technical Challenge

Technical SEO issues often create invisible barriers to ranking potential. This case study identifies the specific technical challenges addressed, from crawlability issues to performance bottlenecks. Understanding the problem scope helps practitioners diagnose similar issues.

The barrier here is not crawlability, it is task completion, and it is worth being precise about that rather than stretching the case study into a ranking claim. A user who abandons a recipe halfway through because the screen went dark does not convert, does not return, and does not send any of the engagement signals a publisher depends on. The technical challenge is delivering a device level capability from a web page, with graceful degradation on browsers that do not support it, without ever gating the recipe content itself behind the API.

Diagnostic Process

Identifying technical issues requires systematic analysis using crawling tools, log file analysis, and Search Console data. This case study documents the diagnostic methodology that uncovered actionable issues. The process itself provides value for practitioners building technical audit capabilities.

This class of problem is invisible to crawlers and log files, which is exactly why it survives so long. It surfaces in three other places: session recordings that show repeated tap and wake behaviour partway through long pages, support and app store style feedback complaining that the page keeps going dark, and time on page distributions that collapse right around the device's default screen timeout. Chrome DevTools has no wake lock inspector, so verification is manual: request the lock on a real phone, background the tab, return, and confirm the sentinel was reacquired by logging the release event and the request result.

Implementation and Solutions

Each identified issue required specific technical solutions implemented within development constraints. The case study details solutions for rendering issues, performance optimization, crawl management, and indexation improvements. Implementation approaches balance ideal solutions with practical constraints.

A shippable implementation is roughly five decisions:

1. Feature detect first. Render the toggle only when 'wakeLock' in navigator is true, so unsupported browsers never see a dead control.
2. Make it opt in. Request the lock from a user gesture, not on page load. It sets the right expectation and avoids surprising battery drain.
3. Reacquire on visibility. The listener pattern above, guarded by the user's stored intent.
4. Release deliberately. When the user toggles off, when they navigate away from the step by step view, and optionally after a long idle period.
5. Never gate content. The recipe, ingredients and schema markup all render normally with or without the API. This is progressive enhancement, so a browser without support loses a convenience, never the content.

That last point is the one with SEO consequences. Any pattern where the useful content only appears after a device API succeeds is a rendering risk, and the wider category of user experience work that sits outside the three Core Web Vitals is covered in site speed beyond Core Web Vitals.

Measurable Impact

Technical improvements demonstrate value through measurable outcomes: improved crawl stats, faster indexation, better Core Web Vitals scores, and ultimately improved rankings and traffic. This case study quantifies the impact of technical optimization.

The reported outcome for BettyCrocker.com is a 300 percent increase in purchase intent indicators, which in a recipe context means actions such as saving a recipe, adding ingredients to a list, or clicking through to buy. To measure the same thing on your own site, instrument three events and compare sessions where the wake lock was active against sessions where it was available but not used: the toggle activation itself, the downstream intent action, and completion depth such as reaching the final step. Keep the comparison within mobile traffic only, and be honest that users who enable the feature are already more committed, so treat the result as directional unless you can run a genuine split test.

The engagement side is worth watching too, since a screen that stays awake changes session duration mechanically. If you also want to check that the added interaction has not hurt responsiveness, the diagnosis steps in INP too high apply, and the broader mobile experience questions are collected in our mobile SEO FAQ.

Technical SEO case studies like this one help practitioners understand the tangible value of investing in site infrastructure.

This technical SEO case study demonstrates how resolving technical issues and optimizing site infrastructure directly impacts organic visibility. The documented approach provides a template for technical optimization initiatives.

FAQ

Source: https://web.dev/betty-crocker/