How to Tell If a Website Uses ConvertKit (Kit)

ConvertKit — rebranded to Kit in 2024 — is the email platform built specifically for creators: newsletter writers, bloggers, authors, podcasters and course creators who grow and monetise an audience by email. To tell whether a site uses it, the quickest answer is to inspect a signup form for an embed from f.convertkit.com (the ck.5.js script) with a data-uid attribute. This guide covers every reliable signal, the creator-focused model behind them, and what a ConvertKit/Kit integration tells you about the business.

What is ConvertKit (Kit)?

ConvertKit, founded in 2013 and renamed Kit in 2024, is an email-marketing platform designed around the needs of creators rather than traditional businesses. Its features reflect that focus: easy signup forms and landing pages, tag-based subscriber organisation, simple visual automations (sequences), a creator-friendly editor, paid newsletters and digital-product sales, and a recommendation network that helps creators grow each other's lists. It deliberately favours simplicity and audience relationships over the complex segmentation of ecommerce-focused tools.

For detection, the key context is that ConvertKit/Kit signals a creator or small media operation — someone whose business is built on a direct audience relationship via email. The profile is a newsletter writer, blogger, author, course creator, coach, podcaster or YouTuber. Its on-site footprint comes almost entirely from embedded forms and landing pages, which load from convertkit.com (and increasingly kit.com) domains and are easy to recognise.

How ConvertKit appears on a website

ConvertKit/Kit forms are the primary on-site signal. Inline, modal and slide-in forms embed via a script from f.convertkit.com/ckjs/ck.5.js (the version may vary), and the form markup carries a data-uid attribute identifying the specific form, along with form and sequence identifiers. Submissions post to app.convertkit.com (or the newer app.kit.com). Hosted landing pages live on ConvertKit/Kit domains too.

Because ConvertKit rebranded to Kit, you may encounter both convertkit.com and kit.com references — existing embeds largely retain the f.convertkit.com and app.convertkit.com hosts, while newer assets and links may use kit.com. Either way, the data-uid form attribute and the f.convertkit.com embed script are the cleanest signals. Knowing these — the f.convertkit.com embed, the ck.5.js script, the data-uid attribute, and the app.convertkit.com/app.kit.com submission target — makes ConvertKit/Kit straightforward to confirm.

How to tell if a website uses ConvertKit (Kit)

Confirm at least one strong signal (the form embed usually suffices).

1. Inspect the signup form. Find a newsletter form, inspect it, and look for a data-uid attribute and an embed script from f.convertkit.com. This is the definitive signal.

2. View the source or Network tab. Search or filter for convertkit or kit.com. The f.convertkit.com/ckjs/ck.5.js script and references to app.convertkit.com/app.kit.com confirm the platform.

3. Submit or examine the form action. Forms submit to app.convertkit.com or app.kit.com; the target confirms ConvertKit/Kit.

4. Read the data-uid. The data-uid attribute (and form ID) identifies the specific ConvertKit/Kit form and account.

5. Check landing pages. A hosted landing page on a ConvertKit/Kit domain is an additional confirmation.

What the ConvertKit/Kit signals look like

<script async data-uid="abc123def4" src="https://f.convertkit.com/abc123def4/index.js"></script>
<script src="https://f.convertkit.com/ckjs/ck.5.js"></script>
<form action="https://app.convertkit.com/forms/123456/subscriptions" data-sv-form="123456" data-uid="abc123def4">

The combination of an f.convertkit.com embed, the data-uid attribute, and an app.convertkit.com/app.kit.com submission target is conclusive.

ConvertKit versus other email tools — avoiding false positives

Match the host to keep creator and email tools distinct. ConvertKit/Kit uses f.convertkit.com, app.convertkit.com and kit.com; Mailchimp uses list-manage.com; beehiiv (a newer creator-newsletter tool) uses beehiiv.com; Substack is a hosted platform on substack.com; ActiveCampaign uses activehosted.com. The data-uid attribute and f.convertkit.com embed are characteristic of ConvertKit/Kit. The main subtlety is the rebrand: do not treat kit.com and convertkit.com as different platforms — they are the same. Also, a creator might use ConvertKit for email but host their site elsewhere (a blog, a personal-site builder), so the form embed may be the only on-site signal, which is still sufficient.

How reliable is each ConvertKit/Kit signal?

An f.convertkit.com embed with a data-uid attribute is definitive, as is a form submission to app.convertkit.com/app.kit.com. The ck.5.js script is strong confirmation. References to kit.com corroborate post-rebrand. The weakest situation is a creator who collects emails through a third-party form and pushes to ConvertKit via API, leaving no convertkit.com embed — uncommon, since ConvertKit's own forms are the norm. As a rule, the form embed or the submission target settles it, and the data-uid makes the finding form-specific.

What a ConvertKit/Kit integration reveals about a business

Finding ConvertKit/Kit signals an independent creator or small media business built on a direct audience relationship. The profile is distinctive: newsletter writers, bloggers, authors, course creators, coaches, podcasters and YouTubers who treat their email list as their core asset. The presence of multiple forms or a hosted landing page indicates active list-building, and paid-newsletter or product features suggest direct monetisation. If you sell to creators — audience growth, monetisation, course and community tools, design or writing products — a ConvertKit/Kit user is an ideal-fit creator-economy prospect. Because ConvertKit favours simplicity, its presence also tells you the creator prioritises audience relationships and ease over complex marketing automation, which shapes what complementary tools would resonate.

What finding ConvertKit/Kit means for sales, agencies and competitive research

For sales and prospecting, ConvertKit/Kit is a precise creator-economy signal: the business monetises or grows an audience by email, making it a fit for creator tools, monetisation platforms, course and community software, and audience-growth services. The kind of forms and any paid-newsletter features reveal how far along the monetisation path the creator is.

For agencies and consultants, finding ConvertKit tells you the client is creator-minded and values simplicity, so engagements can focus on list growth, newsletter strategy, automation sequences, or product launches rather than enterprise marketing. It also signals an audience asset you can help grow or monetise.

For competitive and market research, ConvertKit/Kit adoption maps the creator landscape in a niche. Spotting a competing newsletter on ConvertKit versus a hosted platform like Substack or beehiiv tells you how they balance control, monetisation and ease — useful when positioning your own creator offering or benchmarking audience strategies.

ConvertKit/Kit in the wider creator stack

ConvertKit/Kit is the email hub of a creator's operation, and the tools around it reveal how the creator works and monetises. The host site is typically a blog, a personal-brand site on a no-code builder, or a link-in-bio page driving signups; the email list is the asset, and everything points toward growing it. Alongside ConvertKit you will commonly find a digital-product or course tool (Gumroad, a course platform, or ConvertKit's own commerce features), a podcast or video presence, and lightweight, privacy-respecting analytics rather than a heavy martech stack — creators tend to favour simplicity.

The ConvertKit features in evidence sharpen the read. Multiple forms and a hosted landing page indicate active, deliberate list-building; paid-newsletter or product features signal direct monetisation of the audience; and recommendation-network widgets point to a creator actively cross-promoting to grow. For an auditor, the valuable details are the kinds of forms in use, whether commerce or paid-newsletter features are present, the host-site type, and any course or product tools that accompany ConvertKit; together these describe where the creator sits on the path from audience-building to monetisation — which is precisely the context a creator-economy vendor needs to pitch the right product at the right stage.

A quick ConvertKit/Kit confirmation walkthrough

Open the site and find a newsletter or signup form. Right-click and inspect it, looking for a data-uid attribute and a nearby embed script from f.convertkit.com. Open developer tools on the Network panel and filter for convertkit or kit.com to see the embed and any app.convertkit.com/app.kit.com submission. Read the form's action to confirm the ConvertKit/Kit submission target. The f.convertkit.com embed with a data-uid is enough to confirm the platform and identify the form.

A quick ConvertKit/Kit detection checklist

• Inspect the form for a data-uid attribute and an f.convertkit.com embed — conclusive.
• Filter the Network tab for convertkit or kit.com.
• Check the form action for app.convertkit.com / app.kit.com.
• Look for the ckjs/ck.5.js script.
• Treat kit.com and convertkit.com as the same platform (2024 rebrand).
• Read the data-uid to identify the specific form.

Detecting ConvertKit/Kit at scale

Checking one site is quick, but finding every creator on ConvertKit/Kit across a list — to prospect the creator economy — calls for automation. StackOptic detects ConvertKit (Kit) and thousands of other technologies from a real browser, recognising both convertkit.com and kit.com signals. For related reading, see our guide to finding what email marketing platform a website uses and the full ConvertKit technology profile.