Preparing to ship the Privacy Sandbox relevance and measurement APIs - Chrome Developers (2023)

The Privacy Sandbox project is gearing up to ship the relevance and measurement APIs to Chrome Stable. On the project timeline for the web, we show general availability (GA) starts in Q3 2023. Specifically, we intend to target Chrome Stable 115, which means we'll begin making the APIs generally available from late July, 2023.

In this post, we review multiple components of this launch, including:

  • What's shipping. The relevance and measurement APIs launching are Topics, Protected Audience, Attribution Reporting, Private Aggregation, Shared Storage, and Fenced Frames. We'll make these APIs available gradually to monitor for potential issues.
  • The official launch process. Each API goes through the standard Chrome launch process, which includes individual "Intent to Ship" messages published on the blink-dev mailing list for approval.
  • Updated user controls. Users will have Ad privacy controls to manage the APIs.
  • Status of the origin trial. The origin trial will continue to be available through to Stable release.
  • Enrollment. Enrollment will be available in June and required to access the relevance and measurement APIs in August.
  • Chrome-facilitated testing. We're preparing options for developers to test the APIs without third-party cookie data.

We'll keep you posted as we get closer to GA. For now, the only immediate action for developers is to become informed. By identifying what changes are coming, you can ensure your sites are ready.

When we say "GA," we mean the APIs are available by default in Chrome, without requiring browser flags or participation in an origin trial. However, this does not mean 100% of Chrome browsers immediately have the APIs enabled—the APIs will be made available gradually, and users can always control if the APIs are active. Once we are ramped up, the ecosystem can use the APIs in production.

Preparing to ship the Privacy Sandbox relevance and measurement APIs - Chrome Developers (1)

These are the same set of APIs available for testing in the relevance and measurement origin trial. The feedback we received from the ecosystem during testing has been absolutely critical in shaping this functionality to meet important use cases. We're grateful to all of you who have been testing, reporting issues, and sharing your results with the world—it's a genuinely collaborative effort!

# What's shipping

The relevance and measurement APIs include:

(Video) Privacy Sandbox: Current stages of ads, measurement and content APIs

  • Topics: Generate signals for interest-based advertising without third-party cookies or other user identifiers that track individuals across sites.
  • Protected Audience: Select ads to serve remarketing and custom audience use cases, designed to mitigate third-party tracking across sites. (This API was previously named FLEDGE. As we head towards launch, we've updated the name to better reflect the functionality.)
  • Attribution Reporting: Correlate ad clicks or ad views with conversions. Ad techs can generate event-level or summary reports.
  • Private Aggregation: Generate aggregate data reports using data from Protected Audience and cross-site data from Shared Storage.
  • Shared Storage: Allow unlimited, cross-site storage write access with privacy-preserving read access.
  • Fenced Frames: Securely embed content onto a page without sharing cross-site data.

# Shipping features in Chrome

Preparing to ship the Privacy Sandbox relevance and measurement APIs - Chrome Developers (2)

All proposals for new web platform features, including those in the Privacy Sandbox, go through our standard process to ship new functionality in Chrome. Each milestone in an API's lifecycle is signaled by an Intent message that we share on the public blink-dev mailing list. That means for each of the Privacy Sandbox features, we sent an "Intent to Prototype" (I2P) when we shared the initial proposal for discussion and an "Intent to Experiment" (I2E) when we made the features available for testing via origin trial.

Soon, we'll send an "Intent to Ship" (I2S) message to blink-dev for each feature. The I2S messages will include additional detail on exact functionality and the plan to target Chrome version 115. An I2S must receive approvals from three Chromium API owners before it can proceed.

The APIs will not immediately be enabled for all browser instances with the Stable release. As with some previous Privacy Sandbox features, we'll gradually enable the APIs for an increasing percentage of browser instances to ensure that we can monitor and respond to any potential issues. As we progress, we'll share the status across our developer channels: here on, the blink-dev I2S threads, and the developer mailing lists.

# Already shipped

The relevance and measurement APIs are a critical piece of the Privacy Sandbox project. But, there are also some significant milestones we've already hit and plenty more to come:

  • User-Agent reduction: Limit passively shared browser data to reduce the volume of sensitive information which leads to fingerprinting, while providing User-Agent Client Hints to actively request data. We began reduction of these values in May 2022 and completed in May 2023.
  • CHIPS: Allow developers to opt-in a cookie to partitioned storage, with a separate cookie jar per top-level site. CHIPS became available in Chrome Stable in February 2023.
  • First-Party Sets: Declare relationships among sites to allow for limited cross-site cookie access using the Storage Access API. First-Party Sets is slowly rolling out with Chrome Stable 113, this week.
  • Federated Credential Management (FedCM): Support federated identity without sharing the user's email address or other identifying information with a third-party service or website, unless the user explicitly agrees to do so. FedCM shipped in November 2022.

# Updated user controls

Alongside shipping the web platform APIs, we're updating the interface in Chrome to configure the features. We're evolving this interface from the trial participation controls to be more integrated with the overall Chrome settings. Currently, we're testing an updated Ad privacy interface with a small percentage of Chrome Stable users.

Developers can preview these controls by setting the chrome://flags/#privacy-sandbox-settings-4 flag. We're continuing to evaluate the updated controls and the current version may differ from what we ship by default. However, these user controls don't change how sites interact with the API surface—the methods for feature detection and calling the APIs remain the same.

(Video) Privacy Sandbox: Preserving trust & usability with new APIs for a private web

Preparing to ship the Privacy Sandbox relevance and measurement APIs - Chrome Developers (3)

# Origin trial

The Privacy Sandbox Relevance and Measurement origin trial allows sites to run unified experiments across Attribution Reporting, Protected Audience, Topics, Fenced Frames, and Shared Storage. We intend to continue the origin trial through to Chrome Stable 115. Testers participating in the origin trial may see some gaps in availability or data from the APIs as Stable rolls out, and we will provide additional guidance and details to help testers manage this transition.

We'll update our documentation as this progresses.

# Enrollment and next steps

Alongside GA, we want to ensure these APIs are used as intended and with transparency. We announced a new developer enrollment process for Privacy Sandbox relevance and measurement APIs, across Chrome and Android. We'll share updates and instructions in the enrollment documentation.

# Chrome-facilitated testing modes

We intend to provide Chrome-facilitated testing that allows sites to meaningfully preview what it's like to operate in a world without third-party cookies. This will allow us to perform more effective API testing and grow confidence within the ecosystem, as to its readiness for third-party cookie phase out.

We have worked with the CMA to ensure these testing modes align with the testing framework (and timeline) for third parties laid out in its note on Quantitative testing of Google's Privacy Sandbox technologies. As a result, the CMA anticipates that the results from testing in these modes can be used in its assessment of the Privacy Sandbox.

We plan to have two modes of Chrome-facilitated testing:

(Video) Privacy sandbox | Q&A

  • Mode A: Ad techs can receive control and experiment labels on a portion of traffic and use these to conduct testing and experiments.
  • Mode B: Chrome globally disables third-party cookies for some portion of all Chrome users.

These details are not final, and we'll publish further implementation guidance as we progress in Q3 2023. The current proposals are as follows.

# Mode A: Opt-in testing

Ad techs will be able to receive experiment labels for a portion of Chrome traffic. An ad tech can choose to coordinate with other ad techs, for example, to run Protected Audience auctions without third-party cookies for a consistent experiment group. Ad techs can also use these labels for their own independent experiments and testing.

Chrome will not modify the state of third-party cookies for users in Mode A. Chrome only provides the labels, as to ensure that ad techs can experiment with consistent control and experiment groups. This means that a publisher's site could still receive third-party cookie data for the publisher's own usage, even if their ad tech partners are participating in the experiment.

We expect this to allow for meaningful experimentation, where all involved sites and services can coordinate to ensure third-party cookies are not used at any point within the process. We anticipate providing labels for up to 10% of Chrome browsers via a new request header and low-entropy client hint. We encourage anyone interested in testing to provide feedback from the ecosystem on the method for accessing labels and the granularity of labels.

We plan to make the opt-in testing mode available starting in Q4 2023, and we'll continue this mode until third-party cookie deprecation.

# Mode B: 1% third-party cookie deprecation

Chrome will deprecate third-party cookies for up to 1% of browsers. There is no opt-in for this mode, as it will be applied globally. There is, of course, the possibility that some site features may be impacted if the site hasn't yet adopted an alternative solution, such as CHIPS or First-Party Sets.

(Video) Privacy Sandbox: Journey and outlook

If you rely on third-party cookie data for site functionality, read our guide to prepare for third-party cookie phase-out to understand if CHIPS or First-Party Sets can address your needs. We've launched a public issue tracker, where you can report site issues resulting from third-party cookie deprecation.

We're working on mitigations to detect, address, and proactively alert site owners of issues that impact user experience during this phase.

Additionally, we plan to provide a small fraction of traffic within Mode B that has Privacy Sandbox relevance and measurement APIs disabled. Other APIs, like First-Party Sets, CHIPS, FedCM, and so on, will not be disabled. We anticipate that this combination will be helpful to establish a baseline of performance without third-party cookies, and we're seeking feedback on an appropriate fraction of traffic to devote to this subset of testing.

We plan to deprecate 1% of third party cookies in Q1 2024, and we'll work closely with the CMA before taking further steps to expand deprecation.

# Engage and share feedback

If you're not already participating in the relevance and measurement origin trial, you can still sign up and experiment with these APIs. By signing up now, you'll have a chance to get more familiar with how these APIs work in practice and try different techniques before they are widely available.

Feedback from a diverse set of stakeholders across the web ecosystem is critical to the Privacy Sandbox initiative. Our dedicated feedback section provides an overview of the existing public channels, where you can follow or contribute to discussion, along with a feedback form to ensure you can always reach the Chrome team directly.

(Video) Privacy Sandbox: A view into industry's feedback

If you're a developer, you can ask questions and join discussions in the Privacy Sandbox Developer Support repository on GitHub.


What is Privacy Sandbox API? ›

The Privacy Sandbox on Android aims to develop new technologies that improve user privacy and enable effective, personalized advertising experiences for mobile apps. We welcome industry feedback on the design proposals, and encourage testing as both Developer Preview and Beta releases become available.

How do I enable Privacy Sandbox ads Apis? ›

Enable the Privacy Sandbox trials in Chrome Settings: Settings > Security and privacy > Privacy Sandbox. This is also accessible at chrome://settings/privacySandbox .

What is the origin trials Privacy Sandbox? ›

The Privacy Sandbox Relevance and Measurement origin trial provides a single trial allowing sites to run unified experiments across Attribution Reporting, FLEDGE, Topics, Fenced Frames, and Shared Storage.

What is Privacy Sandbox on Chrome? ›

The Privacy Sandbox is a collaborative initiative to build new privacy-preserving technologies as an alternative to third-party cookies. The goal is to improve user privacy while preserving the vitality of the open web by supporting key marketing use cases for online businesses.

How do I use Chrome Privacy Sandbox? ›

This feature can be turned on or off anytime.
  1. On your device, open Chrome.
  2. At the top right, click More. Settings.
  3. Go to Privacy and security. Privacy Sandbox.
  4. Turn Trials on or off.

What is Chrome sandbox mode? ›

What is sandboxing in ChromeOS? Sandboxing is the process of running individual websites and web applications as their own independent processes. Think of it like a layer of protection that helps guard against phishing and malware, so you can have peace of mind when it comes to your online security.

What happens if I turn off Privacy Sandbox? ›

After opening this subsection, disable the Privacy Sandbox to opt out. Now your Chrome browser will never join the program. However, when Google releases Privacy Sandbox as a stable feature for all Chrome users, it may be re-enabled by default.

Can I turn off Privacy Sandbox? ›

In Chrome on Android, open the main menu, then go to Settings > Privacy and security > Privacy Sandbox. In the desktop Chrome browser, the setting can be found by pasting chrome://settings/privacySandbox into the address bar and pressing Enter.

Should I turn on Privacy Sandbox trial? ›

Privacy Sandbox Is Harmful to User Autonomy

Privacy Sandbox will erode the Web's most important and unique principle: the Web is for people first and foremost. These principles, that the Web is for users first, and that the Web should give users control and power, are enshrined in core W3C documents.

What is the purpose of the app sandbox? ›

The aim of application sandboxing

Application sandboxing seeks to improve security by isolating and shielding the application from outside intruders or malware. It's also used when preventing system resources or other applications from interacting with the protected app is necessary.

Why is sandbox safe? ›

Sandboxing works by keeping potentially malicious program or unsafe code isolated from the rest of the organization's environment. This way, it can be analyzed safely, without compromising your operating system or host devices. If a threat is detected, it can be removed proactively.

How does browser sandbox work? ›

Browser Sandboxing is a security model that works by physically isolating Internet users' browsing activity from the infrastructure, local computers, and networks. There are two main browser isolation techniques: Local browser isolation works by running the browser in a container or virtual machine.

What does Chrome no sandbox do? ›

--no-sandbox disables one of Chrome's more important security mechanisms. This is sometimes necessary for development, for example when you want to redirect stdout to disk and the sandbox would otherwise prevent writing data to the disk.

What does the Chrome and Android Privacy Sandbox aim to achieve? ›

Our goal with the Privacy Sandbox is to enhance user privacy while providing businesses with the tools to succeed online. Blunt approaches that don't provide viable alternatives harm app developers, and they don't work for user privacy either, leading to less private ways of tracking users like device fingerprinting.

Which browser supports sandbox? ›

sandbox attribute for iframes on Chrome is fully supported on 4-114, partially supported on None of the versions, and not supported on below 4 Chrome versions. sandbox attribute for iframes on Safari is fully supported on 5.1-16.4, partially supported on None of the versions, and not supported on 3.2-4 Safari versions.

How do I set up private Internet access on Chrome? ›

Go to the Chrome Web Store, search for Private Internet Access, and click Add to Chrome. Click on the extension icon, sign in, click the connect button, and you're good to go. If you have questions about setup, reach out to our 24/7 Customer Support team.

How do I check my chrome sandbox? ›

You can access this by typing chrome://sandbox into the url-bar (Omnibox). The output is mainly of interest to Chromium developers but, along with chrome://conflicts, could be helpful when troubleshooting incompatibility between misbehaving software and the sandbox.

How do I enable sandbox mode? ›

Use the search bar on the task bar and type Turn Windows Features on or off to access the Windows Optional Features tool. Select Windows Sandbox and then OK. Restart the computer if you're prompted. If the Windows Sandbox option is unavailable, your computer doesn't meet the requirements to run Windows Sandbox.

Why is it called sandbox mode? ›

Sandbox games are often associated with an open world concept which gives the players freedom of movement and progression in the game's world. The term "sandbox" derives from the nature of a sandbox that lets children create nearly anything they want within it.

What are the disadvantages of sandbox? ›

How safe is sandboxing?
No unauthorized data access to the host systemComplex sandbox tools are costly and require lots of resources
No conflict between programs or operating system and programs
Secure online browser by protecting against malware
2 more rows
Sep 29, 2020

Is sandbox a malware? ›

A sandbox is a system for malware detection that runs a suspicious object in a virtual machine (VM) with a fully-featured OS and detects the object's malicious activity by analyzing its behavior.

How do I remove Privacy Sandbox from Chrome? ›

# User opt-out

Disable the Privacy Sandbox trials in Chrome Settings: Settings > Security and privacy > Privacy Sandbox. This is also accessible at chrome://settings/privacySandbox .

How do I get out of sandbox? ›

6 ways to stop Google Sandbox from affecting your SEO efforts
  1. Index your website. You probably think that it's the most obvious thing to do. ...
  2. Make sure you have no penalties. ...
  3. Focus on content. ...
  4. Build backlinks step-by-step. ...
  5. Buy an already active website. ...
  6. Drive traffic from social media.
Dec 9, 2020

How do I stop my sandbox from running? ›

"Program Stop" Settings Group

Sandboxie Control > Sandbox Settings > Program Stop: Settings in this section control when Sandboxie automatically ends programs that run in the sandbox.

How do I disable sandbox in browser? ›

Open the live app for which you want to deactivate (turn off) the sandbox feature. Click the Live button, and then select Disable sandbox feature.

Is it necessary to do sandboxing? ›

Without sandboxing, software or applications could have potentially unlimited access to all the user data and system resources on a network. Sandboxes are also used to safely execute malicious code to avoid harming the host device, the network or other connected devices.

What does it mean disable sandbox? ›

Sandbox mode is a security feature that prevents Access from running certain expressions that could be unsafe. These unsafe expressions are blocked regardless of whether the database has been 'trusted' – its content enabled.

Is the sandbox safe? ›

Sandboxes are safe if constructed and filled with appropriate materials and properly maintained. Sandbox frames should not be made with inexpensive railroad ties.

Does the sandbox app cost money? ›

You can sign up for an account using your email address, phone number, Facebook account, Google account, or Apple ID. Signing up and creating a Sandboxx account is free.

What are the benefits of data sandbox? ›

Benefits of Data Sandbox

You need to analyze without having access to any of your original data source's connection credentials (e.g., if you've lost the key due to network issues). It also helps prevent possible security breaches or leaks by thoroughly testing all data before being deployed on production systems.

Can viruses bypass sandbox? ›

Sandboxing technology is widely used for malware detection and prevention, so hackers search for ways to teach their malware to stay inactive in the sandbox. In this way, sandbox-evading malware can bypass protections and execute malicious code without being detected by modern cybersecurity solutions.

Does sandboxing prevent malware? ›

Without sandboxing, applications or software could possibly have unrestricted access to all user information and network system supplies. Sandboxes are sometimes used to safely execute malware to avoid causing harm to the host computer, the connection, or other associated devices.

Is sandbox 100% safe? ›

The software or applications that you install inside the Windows sandbox environment remain "sandboxed", and they all run separately from the host machine. So whatever happens in the sandbox remains there, and your host machine stays 100% safe.

What is Privacy Sandbox on my phone? ›

The Privacy Sandbox Beta provides new APIs that are designed with privacy at the core, and don't use identifiers that can track your activity across apps and websites. Apps that choose to participate in the Beta can use these APIs to show you relevant ads and measure their effectiveness.

How does the Privacy Sandbox work? ›

It allows vendors selected for advertising to take an advertiser's website data and to place users in interest groups specifically defined for a given advertiser, meaning that users can see tailored ads, with no infringement on their privacy.

Should I turn off Privacy Sandbox trials? ›

Privacy Sandbox Is Harmful to User Autonomy

Privacy Sandbox will erode the Web's most important and unique principle: the Web is for people first and foremost. These principles, that the Web is for users first, and that the Web should give users control and power, are enshrined in core W3C documents.

Is sandbox safe or not? ›

No, sandboxing is not a type of malware. On the contrary, it may protect you from malware. It is an environment where you can run software or access files without letting it affect the OS. That means you can test any suspicious program in a sandbox to ensure it's safe.

How do I turn off sandbox on my phone? ›

Open the live app for which you want to deactivate (turn off) the sandbox feature. Click the Live button, and then select Disable sandbox feature.

What are 3rd party cookies? ›

Unlike a first-party cookie set by the website's server, a third-party cookie is usually set by a third-party domain/server (i.e. an ad-based vendor). Third-party cookies are dropped via a specific vendor code or tag deployed on a particular website and stored under a different domain.

What can you do in sandbox mode? ›

Sandbox mode is a security feature that prevents Access from running certain expressions that could be unsafe. These unsafe expressions are blocked regardless of whether the database has been 'trusted' – its content enabled.

How do I opt out of Privacy Sandbox? ›

On your device, open Chrome. Settings. Privacy Sandbox. Turn trials on or off.

What are the benefits of a sandbox? ›

Using a sandbox has a number of advantages:
  • Does not risk your host devices or operating systems. ...
  • Evaluate potentially malicious software for threats. ...
  • Test software changes before they go live. ...
  • Quarantine zero-day threats. ...
  • Complement other security strategies.


1. Getting started with Attribution Reporting
(Google Chrome Developers)
2. Next up on the Privacy Sandbox
(Android Developers)
3. Google Privacy Sandbox Explained & Analyzed: Semi-Technical
(RealTime Cyber)
4. Building the Privacy Sandbox
(Android Developers)
5. Introducing the Google Privacy Sandbox
(Boye & Company)
6. Sam Dutton: What is The Privacy Sandbox
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