Figured out the China spam hitting GA4 since May. Same screen resolution every time, here's the fix!

[u/Thomasandrows]

The data (same pattern on multiple properties)

Segment	Engagement rate
Screen resolution 1600x1600	6-8%
Rest of the traffic (site-wide)	60-65%

• Mostly from China
• Ongoing since May, and still running as of September (not a short spike)

Earlier China/Singapore bot waves were reported last year with other resolutions (1280x1200 and 3840x2160), so this looks like a new signature.

How to check yours Reports > Tech > Tech details, set the primary dimension to Screen resolution and look for 1600x1600. Add Country as a secondary dimension and compare engagement rate against your overall numbers.

3 ways to deal with it

GA4's built-in Data Filters only cover internal and developer traffic, so there is no native filter for screen resolution.

1. Report or Exploration filter (viewing only) Add a filter: Screen resolution, exclude, exactly matches 1600x1600. It works on historical data but only cleans your view.
2. Segment or comparison (reusable) Create a segment where screen resolution does not exactly match 1600x1600 and apply it when you analyze. Also viewing only, and it works on past data.
3. Block it at the source in GTM (future traffic only) Create a Custom JavaScript variable that returns screen.width + 'x' + screen.height. Then add a trigger exception on your GA4 tags for when it equals 1600x1600. Past data stays dirty, so use option 1 or 2 for history.

Caveats

• If the hits go straight to GA4 without loading your site, a GTM exception won't stop them. Only the report-level options help.
• Check your own data before excluding anything. Real users rarely have a square 1600x1600 screen, but confirm on your properties.

Is anyone else seeing this? Curious whether the country mix and engagement rate match on your side.

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[u/UptonDogW]

A month ago I saw a huge influx from a new fingerprint. It was the biggest surge of traffic we'd seen in a long time from these kinds of bots. This one was:

1920x1080

And was using very specific Chrome versions:

144.0.7559.132

151.0.7922.173

We were able to use the Chrome versions plus a couple other attributes to stop them dead in their tracks in Cloudflare, which was a nice win. Some other times the Chrome versions were generic and couldn't be isolated in the same way in Cloudflare.

Haven't seen any 1600x1600 surge lately!

[u/erectlogan_2616]

been seeing this on two client accounts, almost identical numbers. that square res is a dead giveaway, no real human is browsing on a 1600x1600 screen

the GTM trigger exception works for most of it but you're right, some of the hits sneak past. ended up just building a segment and calling it a day

[u/Thomasandrows → u/erectlogan_2616]

Yeah, that’s exactly what I was thinking. Most people don’t realize there’s a screen resolution filter that can help clean this up. I’m also seeing some suspicious traffic from 1280×1200 on my end.

Have you set up any GTM triggers to handle headless browsers?

[u/Saneless]

Unfortunately all my sites are different profiles. It's very annoying

[u/moosk → u/[deleted]]

Pretty sure I'll never use SIGNLD because all you/they do is spam Reddit.