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Important Changes to Chrome and Chromium-based Browsers

By April 12, 2023News & Updates 13 Min Read

New Client Hints meant to reduce user-agent data

Effective April 13, 2023

The world’s biggest web browser, Chrome, is releasing updated Client Hints meant to reduce the amount of passively shared user-agent data. While this change was announced more than 18 months ago, it was only starting on February 1, 2023, that all web traffic initiating from Chromium 110+ based browsers (this includes Chrome, Edge, Opera, and others) on Android or desktop devices had the ability to reduce historically available information in the header of the device using that browser-based technology (more info here). Starting on April 13th, Chromium 113 will reduce user-agent data by default.

What’s a user-agent?

According to Chrome’s own documentation:

“The User-Agent string is an HTTP request header which allows servers and networks to identify the application, operating system (OS), vendor, and/or version of a user agent. Currently, the User-Agent is shared on every HTTP request and exposed in JavaScript.”

Here’s an example user-agent:

User-Agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/ Mobile Safari/537.36

Why user-agent reduction

The goal of user-agent reduction is ultimately more privacy for the end user. New limits on much of the passively shared browser data that has long been included by default, minimizes potentially identifying information that may have been used for passive fingerprinting and other purposes.

Expected impacts for Kochava, other MMPs, and linking providers

While some of the missing user-agent data is available by requesting values as “critical” and/or revisiting cached values from previous context/redirects, this information is vital to what we do in linking and measurement. 

There are two potential, notable impacts that are worth calling out:

Link redirects that involve device model-specific logic will be less consistent.

NOTE: This is true for any entity redirecting web traffic.

Probabilistic attribution using the device’s granular model information for attribution will also be impacted.

Kochava next steps

To ensure no breaking changes are introduced, Kochava will be deploying support updates to improve these new “client hints” during April and you can expect the clicks where we collect the user-agent and the installs and events our SDK processes will continue to function as you’re used to. That being said, we’re encouraging certain clients and partners to take similar steps.

Next steps for clients and partners


Advertisers who do not use the Kochava SDK (where we automatically make calls for user-agent client hints) and instead use our server-to-server APIs will need to use the Client Hints API to request the OS version and device model, and include those when sending events to Kochava. 

The values below must be included with the data in addition to the information you’re already sending, in the following keys:

  • device_model
  • device_os_version

Many advertisers using the Kochava server-to-server integration already do this. If you’re unsure whether this is already in place for your apps, please contact your Client Success Manager or email


Publishers can include this code snippet on their website serving the ads to force the verbose, or critical client hints, to be sent on the clicks and impressions sent to Kochava for attribution. This will resolve both potential impacts noted above.

  • <meta http-equiv=”Accept-CH” content=”Sec-CH-UA-Platform-Version, Sec-CH-UA-Model” />


Networks that send clicks to Kochava via the server-to-server method must make the same updates we made when Kochava performs the redirect. Specifically, you must use the Client Hints API to request the OS version and device model, and include those when sending the click to Kochava. These values must be appended to the requests sent in the following keys:

  • device_model
  • device_os_version

Many networks and media partners sending Kochava server-to-server clicks already do this. If you’re unsure whether this is already in place for your integration, please contact our Integrations team by emailing

Other than the steps outlined above, there are no additional actions that need to be taken. These new values will become available in reporting, similar to how traditional user-agent data surfaced.

Got questions?

If you have questions, please reach out to your Client Success Manager or email
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