It depends on the browser / web server, but the average limit for a URL is 2000 characters. So yes, if you are hitting the limit change it to POST.
This will require changing the form tag:
<%= form_tag('/submit', method: "post", remote: true) do %>
Depending on your current routing, it might also require updating your route: ( since when using resources
POST requests by default are routed to the create
method in your controller )
match '/submit', to: 'submit#index', via: :post