Splitting & extensions

A single funnel shows you the overall picture: total traffic in, total customers out. That's usually not enough. What you really want to know is "which slice of traffic is actually converting?" — which is what splits answer.

After the main funnel, you often want to track what happens next — do customers upgrade? That's what extensions answer.

Splits

A split inserts a filter node between two stages. Everything downstream of the split only shows traffic matching that filter.

Eight split conditions

Condition	Filters by	Example
Traffic source	Referrer domain	"only traffic from reddit.com"
UTM parameter	utm_source, utm_medium, utm_campaign, utm_content, utm_term	"only utm_campaign=summer-launch"
Channel	Auto-categorized channel	"only organic search"
Device type	Desktop, mobile, tablet	"only mobile"
Country	ISO country code	"only US and Canada"
Custom event	A goal you define with `data-fn-goal` or `funnelfizz('event', ...)`	"only users who clicked pricing"
A/B variant	The `?ab=` URL parameter	"only ?ab=frog"
Stripe product	Specific Stripe product ID (TRIAL/CUSTOMER only)	"only Pro tier subscribers"

All conditions combine with AND — a visitor must match every condition in the chain to appear in that split branch.

Auto-categorized channels

The Channel condition uses a server-side categorizer that bucketizes your traffic from referrer + UTM combinations. Buckets:

direct — no referrer, no UTM
organic_search — Google, Bing, DuckDuckGo, etc.
social — X, LinkedIn, Reddit, TikTok, Instagram, YouTube, Facebook
paid — utm_medium=cpc/paid/ads or recognized ad networks
email — utm_medium=email or email-client referrers
ai_llm — chatgpt.com, claude.ai, perplexity.ai, gemini.google.com, copilot.microsoft.com
referral — everything else with a referrer

Visualizing a split

On the canvas, splits look like this:

                        ┌─ [split: mobile] ─▶ CONSIDERATION (mobile) ─▶ TRIAL ─▶ CUSTOMER
                        │
AWARENESS ─▶ CONSIDERATION                                                               
                        │
                        └─ [split: desktop] ─▶ CONSIDERATION (desktop) ─▶ TRIAL ─▶ CUSTOMER

Each branch is independent — you can chain further splits down a branch, connect different providers, even send different emails to each cohort.

Nested splits

You can split a split. "Mobile visitors from the US who came via YouTube" is a three-level nested split that will compute correctly. The canvas auto-lays-out nested branches so they don't overlap.

There's no fixed depth limit, but in practice three levels is about as deep as is readable.

Adding a split in the UI

Click the + button between any two stages on the canvas.
Pick a split condition.
Fill in the value (e.g., country = "US", UTM source = "reddit").
Name the branch (e.g., "US mobile traffic").
Save.

That's it. The branch fills in automatically using the same data sources as the parent funnel.

→ Full details and per-condition configuration: Features → Splitting.

Extensions

Extensions are an optional second-stage pipeline that sits after CUSTOMER, tracking what happens to paying customers — specifically, do they upgrade?

The analogy: your main funnel is "get from stranger to paying customer." Your extension is "get from paying customer to higher-paying customer."

Extension stages

Extensions mirror the main funnel's structure (minus Awareness, because by definition these are people you already have):

Extension Consideration — your paying customers who are active on your product in the reporting window (fired a pageview or an event).
Extension Trial — Extension-Consideration users who started a trial at a higher-priced tier.
Extension Customer — users paying at a higher tier than their anchor product.

The anchor product

When you enable extensions for a funnel, you pick an anchor product — typically your entry-level paid plan (e.g., "Hobby — $9/mo"). The extension then tracks the cohort of customers who bought the anchor, and measures how many of them end up paying for a higher tier.

If a customer:

Still has the anchor subscription → counted in Retained.
Has no anchor but a higher-tier sub → counted in Upgraded (and shows up in Extension).
Has nothing → counted in Churned.

Canvas layout

On the canvas, extensions render to the right of the CUSTOMER stage with a double-line edge (visually distinct from main-funnel edges). They inherit the tint color of the main funnel.

... ─▶ CUSTOMER ═══▶ Ext CONSIDERATION ═══▶ Ext TRIAL ═══▶ Ext CUSTOMER

When to use extensions

Freemium products — you want to know what % of free users convert to paid. Set the free tier as the anchor.
SaaS with multiple tiers — how often do Hobby customers upgrade to Pro? Set Hobby as the anchor.
Lifecycle marketing — use extension stages as triggers for upgrade automations.

When NOT to use extensions

Single-tier products (Stripe has one price → nothing to upgrade to).
Products where upsell isn't the growth lever (e.g., one-time purchases, usage-based billing where everyone's on the same plan and just pays more).

Next: Email → • Automations → • Conversion → • Full funnel tracking →

Splits​

Eight split conditions​

Auto-categorized channels​

Visualizing a split​

Nested splits​

Adding a split in the UI​

Extensions​

Extension stages​

The anchor product​

Canvas layout​

When to use extensions​

When NOT to use extensions​