A Comprehensive Guide to Fixing the ‘TypeError: Failed to Fetch‘ Error in ConvertKit

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As a digital marketer, one of the most frustrating errors you can encounter is the "TypeError: Failed to fetch" message that appears when using ConvertKit forms. I know firsthand how annoying this error can be, both for you and your website visitors trying to subscribe to your email list.

The good news is, after extensive troubleshooting and research, I‘ve discovered the root causes of this error and several proven methods to prevent it. In this detailed guide, I‘ll share everything I‘ve learned to help you permanently fix the "TypeError" issue in ConvertKit.

What Exactly is the "TypeError: Failed to Fetch" Message?

Before we dive into solutions, let‘s briefly cover what the "TypeError: Failed to fetch" message means.

The full error typically says:

"TypeError: Failed to fetch"

It appears when a visitor tries to submit their email address via an embedded ConvertKit form on your website, such as for a signup form or lead generation.

The error prevents the form submission from succeeding, so your visitor never gets added to your ConvertKit email list.

Understandably, this results in confusion and frustration for the visitor. And if it happens consistently, it means you are losing potential email subscribers.

Key Causes of the ConvertKit "TypeError" Error

Through extensive troubleshooting, I‘ve narrowed down two main triggers for this "TypeError" message:

1. Buggy Invisible reCAPTCHA Integration

Many ConvertKit users enable "invisible reCAPTCHA" to prevent bots and spam signups.

Invisible reCAPTCHA runs a background check to verify the form submitter is human, without requiring any extra steps from visitors.

Unfortunately, there seems to be a bug in how ConvertKit verifies the invisible reCAPTCHA response from the user‘s browser. This causes the "TypeError" when verification fails.

2. Extension or Ad Blocker Conflicts

In some cases, browser extensions like ad blockers can interfere with ConvertKit‘s invisible reCAPTCHA processes and cause the error.

For example, privacy-focused extensions may block reCAPTCHA scripts from loading properly or communicating with ConvertKit‘s servers.

So in summary, the "TypeError" primarily stems from:

  • A ConvertKit backend bug authenticating reCAPTCHA

  • Or browser tools blocking necessary scripts

Understanding this helps narrow down how to prevent the error.

Effective Solutions to Fix the ConvertKit "TypeError"

With the root causes identified, we can now focus on proven solutions. I recommend trying these fixes in order until you resolve the "TypeError" issue:

1. Temporarily Disable Invisible reCAPTCHA

Since the invisible reCAPTCHA feature seems tied to the bug, the easiest solution is to simply disable it, which prevents the faulty validation code from running.

Here is how to deactivate invisible reCAPTCHA in ConvertKit:

  • Login to your ConvertKit account

  • Go to Settings → Forms & Landing Pages

  • Scroll down to the "reCAPTCHA" section

  • Toggle the "Use invisible reCAPTCHA" switch OFF

  • Click Save at the bottom

This stops ConvertKit from passing invisible reCAPTCHA data, eliminating the source of the "TypeError" issue.

*Downside: It removes bot detection, potentially allowing more spam signups. But it‘s an easy fix that usually works.

2. Use Standard reCAPTCHA Checkbox

For continued bot prevention, you can switch from invisible reCAPTCHA to the standard, visible reCAPTCHA v2 checkbox.

The steps are:

  • In ConvertKit Settings, turn OFF invisible reCAPTCHA

  • Turn ON the setting for "Use reCAPTCHA v2"

  • Save the changes

Now your form will show a "I‘m not a robot" checkbox that visitors must check before submitting.

This prevents spam without the issues of invisible reCAPTCHA. However, it adds an extra step for visitors, which could impact conversion rates. Still, it‘s a reliable workaround.

3. Disable Browser Extensions Temporarily

If disabling reCAPTCHA doesn‘t fix the issue, try temporarily turning off any browser extensions that could interfere with page scripts, especially:

  • Ad blockers like uBlock Origin or AdBlock Plus

  • Privacy extensions like Privacy Badger or Ghostery

  • Script blockers like NoScript

After disabling relevant extensions, test your ConvertKit form again. If the issue disappears, turn extensions back on one-by-one until you identify the problematic addon.

You can then configure that extension to allow ConvertKit scripts to load properly.

4. Whitelist Your Site in Ad Blockers

Rather than disabling extensions entirely, another option is "whitelisting" your site in ad blocker tool‘s settings:

  • Open the ad blocker‘s Options or Settings page

  • Find the option to whitelist specific sites (e.g. "Disable on these pages")

  • Enter your website URL

This tells the ad blocker to allow all page content to load on your domain, including ConvertKit scripts.

5. Switch to reCAPTCHA v3

ConvertKit recently launched support for reCAPTCHA v3, the newest version.

Like the invisible option, v3 runs quietly in the background without user interaction. Early testing indicates switching to v3 may avoid the "TypeError" issue.

It‘s worth testing as another possible workaround.

6. Contact ConvertKit Support

If the above steps don‘t resolve the problem, I recommend reaching out to ConvertKit‘s customer support team via live chat or email.

Explain you are encountering consistent "TypeError" errors and have tried all recommended fixes. They may have additional troubleshooting tips or be able to escalate the issue.

Hopefully, ConvertKit can also use your report to prioritize fixing the bug at the source.

Why Disabling reCAPTCHA Stops the Error

For understanding, let‘s briefly discuss why disabling reCAPTCHA prevents the "TypeError" issue:

  • User fills out ConvertKit embedded form

  • Form is submitted to ConvertKit‘s servers

  • With reCAPTCHA on: ConvertKit backend tries to validate reCAPTCHA data but fails, causing the "TypeError"

  • With reCAPTCHA off: ConvertKit skips reCAPTCHA validation, so error never occurs

Essentially, turning off reCAPTCHA avoids the faulty validation code altogether.

Preventing Future Issues

While the above solutions should resolve the "TypeError" for now, there are a few best practices I recommend to avoid recurring issues:

Keep ConvertKit Updated

ConvertKit periodically releases backend patches and bug fixes. Keeping your ConvertKit app updated ensures you have the latest error corrections.

Use reCAPTCHA v2 or v3

Stick with the standard v2 checkbox or newer v3 option. Once ConvertKit fixes the bugs with invisible reCAPTCHA, you could potentially switch back.

Notify Visitors of Blockers

Politely ask visitors to disable ad blockers before completing forms, as they can interfere with submissions.

Test Forms Regularly

Routinely test your ConvertKit forms to catch any new issues immediately.

Eliminating Visitor Frustration

As online marketers, we know the value of each potential email subscriber. That‘s why I wanted to provide this comprehensive guide to eliminating the "TypeError" issue and ensure your visitors don‘t encounter roadblocks.

While ConvertKit still needs to fix the underlying bugs permanently, the solutions outlined above should prevent the error until updates are released.

Let me know if you have any other tips for avoiding or troubleshooting the "TypeError" message in ConvertKit. I‘m always looking to expand my knowledge as I continue optimizing my own email forms and subscriptions.


Written by Alexis Kestler

A female web designer and programmer - Now is a 36-year IT professional with over 15 years of experience living in NorCal. I enjoy keeping my feet wet in the world of technology through reading, working, and researching topics that pique my interest.