User-Agent Client Hints (UA-CH): action needed


2/11/2022 4:00 PM

Google Version 4 Client Hints News Web Development

The UK CMA has accepted commitments from Google over the Privacy Sandbox proposals

On 11 February 2022 the UK Competition and Markets Authority (CMA) provided much-needed certainty concerning the future of Google’s Privacy Sandbox and, by extension, the 51Degrees services.

Here’s what you need to know.

Take Action

Version 4.4 of 51Degrees Device Detection supports the changes from Google called User-Agent Client Hints (UA-CH). Versions prior to 4.4 will not support UA-CH. You can find out more about UA-CH at learnclienthints.com.

Get support for User-Agent Client Hints

You now have three options:

  1. If you haven’t already done so, upgrade to our Version 4.4 solution. This will protect you from future changes that Google make to the Chrome User-Agent.

  2. Opt into Google’s User-Agent Reduction Deprecation Trial. 51Degrees cannot do this for you. Once opted in, you will still need to upgrade to Version 4.4 before Q2 2023.

  3. Make your feedback known to Google. You can supply feedback via their form, on the User-Agent Client Hints Github repository, or join Movement for an Open Web by emailing media@movementforanopenweb.com.

If you are a 51Degrees customer, please contact us with any specific questions.

Frequently Asked Questions

Do I need to change data file?

Cloud users will automatically get the latest data files. If you are an existing on-premise customer, you will need to download the latest data files.

Are User-Agent Client Hints a web standard?

No. UA-CH utilize an experimental IETF document, and a document in incubation outside of the W3C process. UA-CH are not ready for “prime time” and have been deployed prematurely. However, Google is...well, Google, so we all have to do what they say! It is for that reason 51Degrees contributed vocally to the debate including inputting into the W3C’s Technical Architecture Group (TAG) design review which is yet to conclude and proposing less impactful solutions to the supposed problems. Google refused to follow the W3C Process to ensure consensus for their change.

Are other browsers deploying UA-CH?

Those based on Chromium including Microsoft are likely to. Others like Brave are not.

Will User-Agents in their current form disappear?

As User-Agents are used by other browsers, search engines, and crawlers, we will be using both solutions for a long time to come. The web is “splintering” around a small number of “walled gardens”. This only serves to increase the complexity of the web which has a disproportionate impact on smaller web participants ☹️.

Are these the last of the changes?

Google’s Privacy Sandbox changes culminate in Privacy Budget. Privacy Budget is subject to CMA oversight. It is too early to know how Privacy Budget will evolve and the outcome the CMA would find acceptable.

What is Movement for an Open Web?

51Degrees led the formation of Movement for an Open Web (MOW) which was highly influential in achieving greater oversight of big tech and providing certainty for all our customers. We all need to watch Google and the CMA like “hawks” to ensure the rules are being followed. Join MOW to support this activity.