How to Use Amplitude to Find Where Signups Stall Before Activation

The short answer: if your product sends fewer than 2 million events a month, Amplitude's Free plan is enough to see which acquisition channel's signups reach activation (pricing page, checked on 26 October 2026), provided you widen the funnel from its one-day default window (funnel guide). The steps: install the Browser SDK and review its defaults, keep first-touch attribution, set a user ID at signup, track the activation event, build a signup-to-activation funnel, widen its window, split it by first-touch source, watch replays where people stop, and let an assistant draft the weekly readout through MCP.

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Settle three numbers before the snippet goes in:

1. Your monthly events. For example, 12,000 trial signups each firing 45 events in their first weeks is 12,000 x 45 = 540,000; add 90,000 marketing-site visitors at 8 events each, 720,000, and the month comes to 1,260,000, inside the 2 million that the pricing page includes free.
2. Your activation event. The one action, taken from your own billing or CRM data, that most paying accounts did early: a first project, an invited teammate, a connected integration. Amplitude measures it; it cannot choose it for you.
3. Your days to activate. How long a typical account takes from signup to that action. It becomes the funnel's conversion window in step 6.

Marketing usually stops counting at the signup, and product usually starts counting after it. The space between the two is where a channel that looks cheap per signup turns out to bring people who never set anything up. The plans and rivals are in the Amplitude glossary entry.

What you need

• An Amplitude project on the Free plan, which needs no card (pricing page).
• A developer for the snippet and two calls, or access to your tag manager.
• UTM-tagged campaign links, since the SDK reads UTM parameters, referrers and click IDs on arrival.

1. Install the Browser SDK and review its defaults

Add the Browser SDK 2 script loader with your API key, or install the npm package (Browser SDK docs). Autocapture switches on attribution, page views, sessions, form interactions, file downloads and page URL enrichment by default; element clicks, frustration signals, network requests and web vitals stay off unless you enable them. Initialise the SDK only once the user ID and final page URL are available, because the docs warn that early events can carry missing or wrong properties.

2. Keep first-touch attribution

Attribution tracking is on by default and runs two ways: campaign values stored as user properties, which is the only way first touch is kept, and campaign values attached to each event. On a single-page app the docs add a caveat that matters here: each in-app navigation replaces the stored campaign, so later events lose the utm_source the visitor arrived with, while the user property keeps it (Browser SDK docs). For this funnel, split by the first-touch user property.

3. Set a user ID at signup

Call setUserId with your internal account ID the moment signup succeeds, so the anonymous visits and the new account become one user. IDs must be strings of at least five characters; shorter ones are stripped from the event, per the same docs.

4. Track the activation event

Send one clearly named event, such as amplitude.track('Project Created'), from the code path that completes activation, with the properties you will want to filter on. Name it in the past tense and keep it stable: every chart you build will point at this name.

5. Build the funnel

Create a Funnel Analysis chart. In the Events module, choose your signup event as step one and the activation event as step two, with the order set to This order; in the Segmentation module, leave all users or pick a saved segment (funnel build guide). Any order and Exact order exist too, but this job needs the sequence.

6. Widen the conversion window

Under "completed within", replace the default of one day with your days to activate from the list above. The interpret guide allows anything from one second to 366 days and counts a user as converted only inside the window. With the default, an account that sets up on day three is a drop-off.

7. Split by first-touch source

Group the funnel by the initial UTM source user property. Each source now shows its signups and the share that activated within the window. The interpret guide notes that average time shows "N/A" once a group-by is applied, so read time to convert on the ungrouped funnel.

8. Watch where people stop

Free includes 10,000 session replays a month (pricing page). Watch a handful from the source with the lowest activation share, starting at signup. A form that confuses people looks different from people who never meant to stay.

9. Let an assistant draft the weekly readout

Connect Claude to the Amplitude MCP server at https://mcp.amplitude.com/mcp, or the EU address if your data lives there, and sign in with OAuth (MCP documentation). Start each session with get_amplitude_context so the assistant picks up your project's definitions, then ask: "Show signup-to-activation conversion by initial UTM source for the last 30 days, with a 14-day window."

The human check: the MCP server can also create and edit charts, dashboards, cohorts and tracking-plan events with your account's permissions, so the person who connects it reads every proposed change before approving it; deletions already arrive as a two-step confirmation. Before the readout goes out, a person opens the funnel from step 7 and checks that the assistant used the same events, the same window and the same dates.

Mistakes the docs point to

• Reading activation on the one-day default, which counts slow activators as lost.
• Splitting by event-level UTMs on a single-page app, where navigation wipes them.
• User IDs shorter than five characters, which Amplitude removes.
• Loading the SDK from a third-party script before the page is ready, which the SDK docs say produces events with missing properties.

The defaults and the meter

Amplitude meters Plus by event, and its SDK defaults switch on page views, form interactions, file downloads and session tracking for every visitor, so the out-of-the-box setup decides how soon you pass the 2 million free events and start paying per event (pricing page). Before launch, turn off the autocapture options this funnel does not use.

The free version of this job is the Free plan plus one spreadsheet. Each Monday, take the funnel's activated accounts by source and set them beside the accounts your billing system marked active or paying for the same cohort. If a source activates well in Amplitude and pays poorly in billing, the activation event is the wrong one, and item 2 of the list at the top needs revisiting before any budget moves.

FAQ

Do I need the Plus plan for this funnel?

No. Funnels, session replay and AI analysis are part of Free; Plus adds custom events and formulas, behavioural cohorts, alerts, heatmaps and two years of data access, per the pricing page.

Why does the funnel show fewer conversions than the database?

Usually the window: a user counts as converted only if both steps fall inside it, one day by default (interpret guide). After that, check that the user ID is set before the activation event fires.

Can the assistant change my Amplitude project?

Yes, through MCP write tools, within your account's permissions. Event and property deletions require a second, confirmed call, and deletes on the main tracking-plan branch take effect immediately, per the MCP documentation.