HeavySet Embedded Form Loading Slowly or Intermittently – HeavySet Tech

Overview

If a HeavySet embedded form loads slowly, spins for an extended period, or loads intermittently, the issue is typically related to:

A missing or improperly placed inline authentication script
A WordPress optimization/caching plugin delaying or modifying HeavySet scripts

In many reported cases, the form does eventually load — but performance is inconsistent due to script execution delays.

This article explains how to diagnose and resolve these issues.

Symptoms

Form spins for several seconds before loading
Form loads sometimes, but not always
Intermittent behavior between page refreshes
Slower performance on first visit
Inconsistent loading across devices or browsers

Root Cause #1: Missing or Improperly Placed Inline Authentication Script

Certain HeavySet forms require an inline authentication script placed immediately below the iframe.

If this script is missing, deferred, combined, or moved elsewhere on the page, the form may:

Load slowly
Initialize inconsistently
Fail to authenticate immediately
Appear to hang before eventually loading

Required Script (Must Be Placed Directly Below the iframe)

<script>
  var apiToken = 'YOUR_API_TOKEN_HERE';
  var iframeId = 'heavySetIframe1';
  if (typeof window.authHeavySetIframe === 'function') {
    window.authHeavySetIframe(apiToken, iframeId);
  } else {
    var script = document.createElement('script');
    script.src = "https://cdn.heavyset.tech/iframe-loader.min.js?v=1";
    script.onload = function() {
      window.authHeavySetIframe(apiToken, iframeId);
    };
    document.body.appendChild(script);
  }
</script>

Critical Requirements

The script must be placed inline directly below the iframe
It must not be moved to the global header or footer
It must not be deferred, delayed, async, or combined with other scripts
It must not be minified in a way that alters execution timing

Even if the form loads sometimes, improper placement can cause delayed or inconsistent initialization.

Root Cause #2: Optimization Plugin Interference

WordPress performance plugins (such as WP Rocket or similar tools) can:

Delay JavaScript execution
Defer scripts until interaction
Combine or minify scripts
Alter third-party script timing

This can lead to slow or intermittent form loading.

For configuration steps and domain exclusions, refer to the separate KB article:

“Configuring WP Rocket for HeavySet Tech Forms”

Follow the instructions in that article to properly exclude HeavySet domains and scripts.

Troubleshooting Checklist

Before escalating:

Confirm auth script is placed directly below the iframe
Confirm script is not deferred, delayed, combined, or minified improperly
Follow the WP Rocket exclusion steps in the related KB article
Clear all caches (plugin, server, CDN)
Test multiple refreshes in incognito mode
Test on both desktop and mobile

Contacting HeavySet Support

If the issue persists, contact HeavySet Tech Support and provide:

The full URL of the page where the iframe is embedded
Confirmation that the auth script is placed directly below the iframe
Confirmation that optimization exclusions were applied
Description of whether the issue is slow loading or intermittent
Any browser console errors (if available)

Providing the exact page URL that contains the iframe will significantly speed up troubleshooting.

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