Yes, Formidable does use caching. We use the WordPress Object Cache as well as transients for specific types of data.

How does the WordPress Object Cache work?

Formidable uses the WordPress object cache to add a caching layer to the vast majority of our database queries. The WordPress Object Cache is a global object that is used to speed up the page load. It cuts down on the number of times the database is accessed when identical queries are made in a single page load.

This caching is typically non-persistent, meaning that data stored in the cache resides in memory only and only for the duration of the request. Cached data will not be stored persistently across page loads unless you install a persistent caching plugin. Here are a few known persistent caching plugins:

• W3 Total Cache
• Memcached Object Cache
• APC Object Cache / APCu Object Cache
• Redis Object Cache

If you are using one of these caching plugins, then the typically non-persistent data will be stored persistently between page loads. Formidable clears cached data when something changes, such as when a form is saved, an entry is updated, or a field is deleted.

If you notice data is not getting updated immediately, your caching plugin may be storing data persistently in a way that Formidable is not clearing. If you are seeing this issue, please create a ticket in our help desk so we can assist you.

Long cache times and form tokens

We don't validate nonces on form submissions by default, because nonces are user-specific and break under page caching. Instead we use the Check entries for spam using JavaScript setting, which works like a nonce but in a way that survives caching.

The token has a limited lifetime. By default, it's valid on the day it's created and for the next 2 days, counted by UTC date. If your cache serves the same page for longer than that window, visitors can hit Form token is invalid. Please refresh the page. You have 3 options:

1. Turn off Check entries for spam using JavaScript (the form's Settings → Spam tab) and click Update. This removes the token check entirely, at the cost of that spam protection layer.
2. Extend how long the token stays valid with the frm_form_token_check_before_today filter. Each value in the $times array is a number of seconds before today. The defaults are 1 day and 2 days. This example accepts tokens up to 30 days old, for a 30-day cache:

   add_filter( 'frm_form_token_check_before_today', function( $times ) {
       for ( $day = 3; $day <= 30; $day++ ) {
           $times[] = $day * DAY_IN_SECONDS;
       }
       return $times;
   } );

3. Keep the token check, but save the submissions it flags for review instead of rejecting them. Go to Formidable → Global Settings → Captcha/Spam and open Customize how spam submissions are handled. Set JavaScript anti-spam check to Save as a spam entry and click Update. It's set to Reject with an error message by default, because bots that fail this check can send many submissions. A flagged submission then shows the normal success message and is saved to the Spam tab of the entries list. From there, you can mark it as not spam. Its form actions, such as email notifications, don't run unless you choose to run them at that point. This option requires Formidable Forms 7.0 or newer. If Formidable Forms Pro or Formidable Views is active, update it to its latest version too.

If you're not sure which to use, choose option 3 (Save as a spam entry): it keeps the token check on without blocking real visitors, who see the normal success message.