For months I’ve had “Page Title Not Defined” popping up in my Matomo analytics. I was concerned about the impact is might be having as it seemed to be fairly consistent “1 per day” coming through. Did I have a bug in my site I needed to fix?
The short answer is no.
After a bit of hunting through server logs I found the culprit. I’ve been subjected to daily spamming through my contact form at a fairly regular rate. The spam’s pretty generic – usually someone trying to sell a freelance writer a bunch of essay writing services. It’s annoying but harmless.
Spammers use software which allows them to fire messages into contact forms and supposedly bypass any captcha or other protections in place. A (welcome) side-effect of this is it doesn’t trigger Matomo properly, hence the “Page Title Not Defined” error.
If you do find “Page Title Not Defined” popping up it is worth having a quick check of your site just to make sure you’re not missing a <title> tag in your heading, as this can also cause it. Otherwise double check your server logs for a correlation between contact or comment form spam and the appearance of the warning.
You can then safely discount these from your analysis, which Matomo has probably done already.