To be fair, even Microsoft does UA sniffing for their own products. I remember there being a post on HN about onedrive website not working in Firefox, but working with a different user agent.

What is UA sniffing mean in this context? :)

User Agent sniffing. :)

The user agent is equal to Chrome with "Edg" (not a typo) appended:

> mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/76.0.3800.0 safari/537.36 edg/76.0.167.1

Certainly not an accident, unless they tried to save one byte by not checking on the full "Edge" token.

They serve this UA on purpose to some sites to prevent being detected as the "old" Edge (which was not Chromium-based).

Very well could be an internal project/component name in MS.

Microsoft's purposely changed Chromium Edge's User-Agent string to say "Edg" [sic] instead of "Edge". They wanted to give sites a way to identify Chromium Edge without accidentally treating it was the old Trident Edge (whose User-Agent string says "Edge"). No one would have written User-Agent string sniffing code that searches for "Edg" instead of "Edge" before Chromium Edge was released.

Thus, Google sites are explicitly targeting Chromium Edge because the only way to differentiate Chrome from Chromium Edge is for the server is to search the User-Agent string for "Edg". If they just searched for "Chromium", then Chromium Edge would be successfully match.

The sad thing is when Google websites refuse to work on Edge Chromium. Switch your user agent to match Chrome's, you're all set.

Out of curiosity, which sites are these? Do they also similarly break with Firefox or other non-Chrome browsers or only MS Edge?

Non-Chromium derivatives are blocked as well, yes, but neo-Edge is a Chromium derivative.

Google Stadia was one example:

https://www.trustedreviews.com/news/why-stadia-access-blocke...

Which websites?

Same with Firefox.

They shouldn't be blocking Firefox either, but let's be clear-- Chromium Edge makes even less sense given it's a "cousin" of Google Chrome.

I wonder why Microsoft isn't doing that, they could just use Chrome user agent for all Google websites.

I agree. Perhaps the old user agent sniffing, from that recent age when Edge was NOT Chromium, is still mostly in place. This seems like the more likely reason to me.

These are new changes. Edge based on Chromium has been available for over a month publicly and in beta much longer. And these examples have just happened, and been introduced in the past week.

Google is actively writing checks for the new Edge and implementing new scare tactics claiming their nearly identical browser that gives them data on you is more secure.

I don't get why promoting your product would be an anti-competitive behavior. Anti-competitive behavior would be not letting Edge users use google or gmail.

It's anti competitive for the same reason auditing companies are not allowed to have consulting arms or if they do, they should not both work for the same customer at the same time. Channel 1 (auditing) vs channel 2 (consulting). At least in theory.

There's a conflict of interest at the heart of the issue.

Google offers a service which is supposed to be neutral (search) and then on top of that it also sells another (ads) which is at odds with search. Good search results should bring the best result but ads are a way to bypass that with cash.

Microsoft had the same problem with Windows (level playing field) + Microsoft made apps on top of Windows (which didn't want a level playing field).

That's a conflict of interest, not anti-competitive.

Yup, search for "Google Chrome" on bing and a loud Edge promotion awaits you.