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

Today 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 of 51Degrees Device Detection (released in 2020) supports the changes from Google called User Agent Client Hints (UA-CH). Versions prior to 4 will not support UA-CH. You can find out more about UA-CH at learnclienthints.com.

You now have two options:

  1. If you haven’t already done so, upgrade to our version 4 solution before April 2022. This will protect you from future changes.

  2. If you can’t deploy version 4 before April 2022 then you will need to 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 before October 2022.

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

Update for June 2022: version 4.4 of the 51Degrees service contains full User Agent Client Hints support. Find out more in our version 4.4 blog.

Frequently Asked Questions

Do I need to change data file?

When you upgrade to version 4, our system will automatically provide you the correct data files. If you use our cloud service everything is done for you.

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 are...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.