Form is sending repeat submissions


I’m having an issue with repeat form submissions.

Previously, this has happened on a smaller scale, so it was hard to say if they were sent manually or if there was a technical issue.

However, this most recent case has me leaning toward a technical issue.

  • Same exact form submission has been sent 14 times over the last 48 hours
  • Submission is a legitimate service request from a customer
  • Send times are sporadic, with no pattern
  • Submissions are coming from multiple sets of IP addresses

Can someone from support please take a look at this? We’ve recently had to pay for more form submissions, so I’d like to resolve this issue before I need to upgrade again.

Here is my site information:


Hi @Michael_Maher,

Thanks for reaching out and welcome to Netlify’s Support Forums!

We have seen that with duplicate form submissions, there is something in the client side javascript which triggers this behavior.

Our best guess is that the following is occurring:

  1. The user submits a form on the site using a mobile device.
  2. The user then opens a new browsing window, leaving the previous window open.
  3. Time passes and the user navigates back to the page when the form was submitted.
  4. The browser does any automatic refresh of the page and the client side javascript triggers a second (duplicate) form submission at this time.

For example, it is quite common for us to see this behavior where the user agent for the device is identical but the IP address and ISP change. In these cases, I suspect it is either someone reopening the browser at a new location triggering a fresh of all pages or maybe it is simply reconnecting to a new internet connection that triggers the refresh.

The ISP changing strongly indicate a mobile devices are the most commonly affected systems. Desktops would be unlikely to change ISPs with such frequency. Mobile devices, however, are likely to use home, office, mobile provider, and other wifi hotspots so changing ISPs many times in a single day is normal for those types of systems.

When issues are caused by client side javascript, we at Netlify don’t have any special insight into the issue because we have no control over or visibility into what happens on the client side.

I found this Netlify Forum post that may help with eliminating the multiple form submissions:

Hope this helps!

1 Like

Hi @Melvin, thank you for the detailed response. This makes sense and explains why a few submissions occasionally submit duplicates.

It’s certainly possible this is also the reason for our edge case, which has 26 duplicate submissions. I wonder which browser he used that refreshed 26 times and kept resending.

It sounds like there isn’t much that can be done on your end or my end, so we’ll continue to monitor the situation.

If anyone else experiences high numbers like 26, I’d love to hear about it so we can analyze for patterns and try figuring out the culprit!


1 Like

Hi there,

We, have been getting this across two different sites so far and I have found it has happened on 10 occasions. I can trace it back over 30 days ago so far.

  • It is the same message
  • it comes from two different ip addresses sometimes. and sometimes the same
  • The time of sending is different

is there any way to fix this issue. This could esclate costs very quickly, This would force a lot of our customers into the higher paid form plans or from the free to paid.

Many thanks

If you just AJAX based submission, this issue should not happen as browsers won’t execute AJAX based submissions on page reloads.