Klaviyo Flows Best Practices: The Complete Diagnostic Guide

Your flows are switched on. The welcome series, the abandoned cart, the post-purchase thank-you are all showing "Live." Yet the revenue they bring in feels smaller than it should be, or it has slipped and you can't see why.

Flows run in the background, so problems hide well. Nothing breaks loudly. A filter, a missing event, or a timing setting can quietly cut a flow's reach for months.

This guide sorts flow problems by what you're seeing. Each section explains the likely causes and what to check first.

Why rewriting the email rarely comes first

When a flow underperforms, most teams reach for the copy. They test new subject lines, a bigger discount, or a fresh design. Those tests can help, but only after you know the email is reaching the right people.

A flow can fail at several points before anyone reads a word. The trigger may not fire. Filters may skip people.

Smart Sending may hold the message back. The email may arrive, get clicked, and then lose the sale on a slow page.

That's why our method is differential diagnosis. It borrows a habit from medicine: list every plausible cause of a symptom, then rule them out with evidence until the true root cause is left.

For a flow, that means reading it in order. Did people enter? Did they receive Email 1?

Did they click? Did they buy? The step where the numbers fall off tells you where to look.

You can read more about the approach in the Email DDx framework.

Start by comparing "entered" with "received"

Before you open any single flow, run one check across all of them. For each core flow, compare how many people entered with how many received Email 1.

If those numbers are close, the flow is reaching people and you can look at content and offers. If received is far below entered, you have a reach problem, and no copy change will fix it.

In Klaviyo, the skipped reasons show up in the flow's recipient activity. Common ones are flow filters, Smart Sending, and missing consent. Klaviyo's help docs note that messages skipped by Smart Sending are not rescheduled, so those people simply never get that email.

This one check often reframes the whole problem. It's where we start when someone tells us a flow "isn't working."

My welcome flow gets opens but no sales

This is one of the most common flow complaints. Opens look healthy, but very few new subscribers place a first order.

The cause usually sits after the open. The offer in Email 1 may not match the signup form.

Past buyers may be entering a flow built for first-time visitors. The main button may send people to the homepage instead of a product or collection page.

Start by reading the flow from delivery to clicks to orders, then compare revenue by email. If Email 1 earns almost everything, the later emails need a different job.

We walk through every check, plus a worked example, in why your Klaviyo welcome flow isn't converting.

I'm not sure how long my welcome series should be

Length is a fair question, but it's best answered after Email 1 is doing its job. A longer series won't rescue a first email that buries the offer or arrives late.

Once Email 1 is working, think about what each later email is for. One might show best sellers.

Another might answer common doubts with reviews or proof. Each email should have a clear reason to exist.

Then let the data guide you. If the last email in the series still earns orders, there may be room for one more. If it earns almost nothing, the series may already be long enough.

We'll go deeper in how many emails belong in a welcome series.

My abandoned cart flow isn't sending

When a cart or checkout flow is live but barely sends, the problem is almost always reach. People are leaving checkout, and the flow never hears about it, or it hears and then skips them.

Start with the trigger event. Count Started Checkout in Shopify and in Klaviyo for the same month. A big gap means events aren't arriving, so people never enter the flow.

Then read the skipped reasons. Flow filters, re-entry rules, and Smart Sending can each hold people back.

Some skips are healthy, like removing someone who already bought. Others quietly cost you sales.

We'll cover each cause in why your Klaviyo abandoned cart flow isn't sending.

My abandoned cart flow stopped converting

A flow that used to sell and now doesn't is a different problem from one that never sent. Here, the email is arriving, but fewer people come back to buy.

Ask what changed around the time the drop began. A new checkout, a price change, a broken discount code, or a template update are all worth writing down. A shift in traffic can matter too, because new visitors may abandon for different reasons.

Then check the basics on a phone. Click every link, try the code, and see where the email sends you. Small breaks after the click are easy to miss from inside Klaviyo.

We'll go through the full list in why your abandoned cart flow stopped converting.

My browse abandonment flow barely earns anything

Browse abandonment catches people who looked at a product but didn't add it to their cart. It reaches a wider and cooler audience than a cart flow, so it earns less per person. That's normal.

The question is whether it's doing its job well. Check that the Viewed Product event is arriving from your store.

Then check who can enter. Someone who browses every day shouldn't get the same email every day.

Smart Sending, which Klaviyo turns on by default for new flow emails, helps here. Pair it with a sensible re-entry window so the flow stays helpful.

We'll share setup and timing ideas in Klaviyo browse abandonment flow best practices.

My post-purchase flow revenue is low

Post-purchase flows often get built once and then forgotten. They send a thank-you, maybe a review request, and that's it.

Low revenue here can mean a few things. The flow may only be thanking people without giving them a next step.

It may send the cross-sell before the order even arrives. Or it may treat a first-time buyer and a loyal customer the same way.

Map out what a customer needs after they buy. Shipping updates and care tips come first, then a reason to come back. Time each email around when the product is likely to arrive and be used.

We'll cover this in why your post-purchase flow revenue is so low.

I don't know if my flows are good or bad

Benchmarks help you see whether a number is unusual. A flow that looks weak on its own may be normal for your industry, or it may be well behind.

Use benchmarks as a starting point, not a verdict. Compare flows of the same type, and compare revenue per recipient rather than open rate. Apple Mail Privacy Protection can inflate opens, so they're a weak base for comparison.

Your own trend matters most. A flow that has slipped steadily for three months deserves a look, even if it still sits near an industry average.

We'll share how to read flow benchmarks by industry, and how to use them without being misled.

A quick flow check you can run this week

If you only have an hour, this order gives you the clearest first read.

List your core flows: welcome, abandoned cart or checkout, browse abandonment, and post-purchase.
For each one, compare entered with received on Email 1.
Read the skipped reasons for any flow with a big gap.
Check that Viewed Product, Started Checkout, and Placed Order still arrive from Shopify.
Compare revenue per recipient by email inside each flow.
Open Email 1 of each flow on a phone and click every link.

Write each finding next to a possible cause. Then fix the confirmed causes in order, starting with anything that stops a flow from reaching people. For a wider pass across the whole account, see how to audit Klaviyo.

Frequently asked questions

Why is my Klaviyo flow live but not sending?

Usually because people never enter, or they enter and get skipped. Check that the trigger event is arriving from your store, then read the skipped reasons in the flow. Filters, re-entry rules, and Smart Sending are the most common causes.

Which Klaviyo flows should a Shopify store have?

Most stores start with a welcome series, an abandoned cart or checkout flow, a browse abandonment flow, and a post-purchase flow. Win-back and sunset flows come next. Get each one reaching the right people before you add more.

Should Smart Sending be on for flows?

It depends on the flow. Klaviyo turns Smart Sending on by default for new flow emails, and it suits flows people can trigger again and again, like browse abandonment. On a time-sensitive email like abandoned checkout, check whether it's skipping people you want to reach.

How do I know which email in a flow is underperforming?

Compare revenue per recipient for each email in the flow, alongside click rate. If one email earns far less than the one before it, that's where to look first. Leaning on opens alone can mislead you because of Apple Mail Privacy Protection.

Sources

Klaviyo Help Center, Understanding Smart Sending in Klaviyo: https://help.klaviyo.com/hc/en-us/articles/115002779311
Klaviyo Help Center, Understanding the default account, email, and list settings: https://help.klaviyo.com/hc/en-us/articles/360004059711
Klaviyo Help Center, How to identify iOS15 Mail Privacy Protection opens: https://help.klaviyo.com/hc/en-us/articles/4416791883163

Find where the flow loses people

Flows are some of the most valuable emails you send, and they're also the easiest to forget. A short, careful check can show you exactly where each one loses people.

If you'd rather have someone walk through it with you, a Klaviyo audit from EmailDDx reads every core flow the same way. We'll show you which causes the evidence confirms, and which fix to make first.