HubSpot forms won't render in Firefox

[Yndira-E]

Current Behavior

A user sent us this message:

Many of your forms do not work w/ Firefox. I had to switch to chrome to see this form, and when I was trying to download an ebook at https://flowfuse.com/ebooks/beginner-guide-to-a-professional-nodered/, the form was missing. Can you either fix this for Firefox or give a warning that this site "works best in Chrome"? I'm running Firefox 138.0.1 (64-bit) on Windows 11 Pro 10.0.22631

I tested the page using Firefox 138.0.1 (64-bit) on Windows 11, and the form loaded correctly on my end.

He later sent this message and images after opening the page on a private window:

The issue still occurs when I go to the page in private mode. I have attached 2 screenshots, NoForm and NoForm_Debug. The top left is firefox, top right is private Firefox, bottom left is chrome.

Seems like there are some scrip load failures in private mode and in regular ff? But I also am seeing a few errors in Chrome so I’m not sure if that’s just normal behavior.

Not a huge deal from my end, but I can send logs if you want. It was just very confusing when I was on the page in my normal browser (ff) and it had nothing for me to interact with!

Thanks for the fast response!

Serban was able to see it correctly, too, on a regular window, but not on a private one, so there is something going on.

There's also something about PostHog throwing a warning, but I'll address that in a different issue.

Expected Behavior

No response

Steps To Reproduce

No response

Environment

• Date: May 8, 2025
• Platform/OS: Windows 11 Pro 10.0.22631
• Browser: Firefox 138.0.1 (64-bit)

Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate

[Yndira-E]

@cstns I've addressed the clearbit issue in this PR.
And the PostHog issue in this one that hasn't been merged yet.

[cstns]

Some info, the hs form is blocked by firefox's Enhanced Tracking Protection. While I was able to reproduce the described behavior, with ETP set to standard or strict, the form loads properly when ETP was set to custom an all the check boxes unticked:

I'm trying to work around this feature without having users disable ETP or make any changes to their browser, which I'm guessing is going to be tricky, First thing that comes to mind is to try and embed the form as raw html and not have it load through their js.

I'll update this issue as I go along.

[Yndira-E]

I was just about to post the same info, although with the Standard Mode I see everything correctly.

I found this in the HS forum. Someone suggests a script to warn them in case the form isn't showing saying something like:

It seems you're using Firefox with strict privacy settings. To be able to submit this form, please adjust your privacy settings or use a different browser. Sorry for the inconvenience!

That could be a first iteration?

Even the HS team doesn't have a better idea, they say it's on Firefox...

[cstns]

My assumption is that EST goes into overdrive when in incognito. The warn would be tricky, can't really think of a proper way to deduce if a user's in incognito mode, maybe handle this on the script's on error callback

[Yndira-E]

Currently, if we change a form in HubSpot, it updates immediately on our website. If you achieve this:

First thing that comes to mind is to try and embed the form as raw html and not have it load through their js.

Would that still be the case? Or would we need to build the site each time we change something on HS?

[Yndira-E]

The warn would be tricky, can't really think of a proper way to deduce if a user's in incognito mode

We could just add that to the warning message:

Hmm… there was supposed to be a form here.
If you’re using Firefox with strict privacy settings or in private mode, it might be blocked.
Try adjusting your settings or switching browsers to continue.

So it's an if, and there's no need to know if they're in a private window.

[cstns]

I think I may have found a better way, by embedding the form straight to the page. This would imply some changes on the HS though, we'd need to enable non-hubspot forms from HS

This would enable HS to capture all forms from the website that have a submit button and email field that are annotated properly, including the plain HTML contact from which I'll have to replace.

I couldn't check our prod account if it's already enabled due to what I assume is my account's limited access, but the setting can be found under settings > marketing > forms > non-hubspot forms tab and look like the picture I attached above.

Until we digest this possibility I'll try and add the warning message

[cstns]

I altered the text slightly to be more of a catch all even though this is ffox specific.

Are you ok with it?