Klaviyo email flows are automated email and SMS sequences triggered by customer behavior, such as a signup, a browse, an abandoned cart, or a purchase. Unlike one-off campaigns, a flow runs continuously once published, sending the right message to each profile based on trigger, filter, and timing logic you define.
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Key Takeaways
- Flows are behavior-triggered and always on; campaigns are one-time sends to a list or segment.
- Five core flows cover most of the revenue opportunity: welcome, browse abandonment, abandoned cart, post-purchase, and win-back.
- Every flow needs three decisions: the trigger event, the profile filters, and the delay timing between messages.
- Flow filters prevent the most common failure mode: emailing a customer who already converted.
- Measure flows on revenue per recipient, not open rate, and review conditional splits before adding more messages.
How Do Klaviyo Flows Differ from Campaigns?
A campaign is a scheduled broadcast: you pick a segment, write one message, and send it once. A flow is a persistent automation that watches for an event and then sends a personalized sequence to whoever triggers it. Campaigns drive spikes tied to promotions and launches. Flows produce compounding baseline revenue because they run without further work once they are live.
The practical implication is where to spend build time. If your automated flows are not live, a promotional calendar is fighting for attention with no safety net underneath it. Flows capture intent that already exists, which is why they typically convert at multiples of campaign rates on a per-recipient basis.
What Are the Building Blocks of a Flow?
Each flow is assembled from a small set of components. Understanding them makes the difference between a flow that reads as helpful and one that annoys subscribers.
| Component | What it controls | Common mistake |
|---|---|---|
| Trigger | The event that enters a profile into the flow (list join, checkout started, order placed, custom event) | Using a list-based trigger when a metric-based trigger is more precise |
| Flow filter | Conditions rechecked before each message sends | Omitting a "has not placed order since starting flow" filter |
| Trigger split | Branches the path based on the triggering event data, such as cart value | Splitting on data that is not present on the event |
| Conditional split | Branches on profile properties or past behavior | Stacking too many branches, making results unreadable |
| Time delay | Spacing between messages, including smart send windows | Sending the first cart reminder hours too late |
| Message | The email, SMS, or push notification itself | Leaving messages in Draft status after publishing the flow |
Which Five Flows Should You Build First?
Most ecommerce and subscription brands capture the bulk of automated revenue from five sequences. Build them in this order, because each one depends on data the previous one exercises.
- Welcome series. Triggered by a signup form or list join. Deliver the promised incentive immediately, then explain what the brand does differently over two or three follow-ups. This is the highest-engagement moment a subscriber will ever have.
- Browse abandonment. Triggered by a viewed-product event with no add to cart. One or two messages, first within a few hours, focused on the specific product viewed plus one alternative.
- Abandoned cart or checkout. Triggered by checkout started. Three messages spaced across roughly 24 to 72 hours: a plain reminder, an objection-handling message covering shipping and returns, then a final urgency message.
- Post-purchase. Triggered by order placed. Set expectations, deliver usage guidance, request a review after the product has plausibly arrived, and then cross-sell a logical companion item.
- Win-back. Triggered by time since last order relative to your typical repurchase interval. Two or three messages that acknowledge the gap and offer a reason to return.
Only after those five are live and profitable is it worth building price-drop, back-in-stock, replenishment, or VIP-tier flows. Those add incremental revenue but require cleaner catalog and profile data.
How Do You Set Trigger Filters Correctly?
Flow filters are rechecked immediately before each message sends, which makes them the safety mechanism for every sequence. The standard set is short. Exclude profiles who have placed an order since entering the flow, so cart reminders stop when someone buys. Exclude profiles who have already received the sequence within a recent window, so repeat browsers are not re-emailed daily. Exclude current customers from acquisition discounts if the discount is meant to convert new buyers only.
Trigger filters, by contrast, are evaluated once at entry. Use them to restrict who qualifies at all, for example only entering an abandoned cart flow above a minimum cart value, or only entering a win-back flow for profiles with more than one historical order. Getting the split between trigger filters and flow filters right eliminates most of the complaints teams have about automation feeling robotic.
What Timing Works Best Between Messages?
Timing should follow the decision speed of the purchase. Low-consideration consumer products reward fast reminders; high-consideration or high-ticket items reward longer gaps and more educational content. A workable default: cart reminder one at 1 to 4 hours, reminder two at roughly 24 hours, reminder three at 48 to 72 hours. Browse abandonment fires within 2 to 6 hours. Welcome message one sends immediately, then messages at day two and day four.
Two timing controls matter beyond the raw delay. Smart sending suppresses a message if the profile received another message very recently, which protects against overlap when several flows are live at once. Send-time windows hold messages until a reasonable local hour, which matters most for SMS steps inside a flow.
How Should You Measure Flow Performance?
Open rate has become an unreliable metric because privacy features prefetch images and inflate opens. Judge flows on revenue per recipient, which normalizes for the very different audience sizes each flow reaches, and on placed-order conversion rate for the specific trigger. A welcome flow with a smaller audience and high revenue per recipient is more valuable than a broad campaign with more total clicks.
When a flow underperforms, check in this order: is the trigger firing at the expected volume, are messages actually Live rather than Draft or Manual, are flow filters excluding more profiles than intended, and is the first message arriving before intent decays. Most flow problems are configuration problems, not copy problems.
How Do Flows Fit the Rest of Your Marketing Stack?
Flows are triggered by events, so their quality is capped by your tracking quality. If checkout-started events are missing or duplicated, no amount of copywriting fixes the sequence. Treat flow setup as a measurement project as much as a creative one: verify the events, confirm identity stitching between anonymous browsers and known profiles, and align the revenue numbers in email reporting with the numbers your analytics and ads platforms report.
The same discipline applies downstream. Feed flow engagement back into paid media as suppression and lookalike audiences, and use post-purchase survey responses to sharpen both segmentation and ad creative. For related reading on the tracking layer, see the guides on server-side tracking and marketing attribution below.
What Are the Most Common Klaviyo Flow Mistakes?
The failure patterns repeat across accounts. The first is overlapping sequences: a browse flow, a cart flow, and a promotional campaign all reaching the same profile within an hour because smart sending was never enabled. The second is discount stacking, where each reminder increases the offer and trains subscribers to abandon carts on purpose. The third is stale content, such as a welcome series still promoting a product line that was discontinued two seasons ago.
Two more are quieter but costlier. Flows built on list membership rather than behavioral events fire late or not at all, because list joins happen once while behavior repeats. And flows without a suppression rule for recent purchasers keep selling an item the customer already owns, which is the single fastest way to increase unsubscribes. Fix these five before adding any new automation.
Frequently Asked Questions
How Many Messages Should a Klaviyo Flow Have?
Three messages is a reliable default for cart and welcome flows, and two is often enough for browse abandonment or win-back. Add a fourth message only when the third still produces meaningful revenue per recipient. Length matters less than sequencing: each message should carry a distinct reason to act rather than repeating the previous one with a larger discount.
What Is the Difference Between a Flow Filter and a Trigger Filter?
A trigger filter is checked once, at the moment a profile enters the flow, and decides whether they qualify at all. A flow filter is rechecked right before each individual message sends, so it can stop the sequence mid-stream. Use trigger filters for eligibility rules and flow filters for safety rules such as suppressing reminders after a purchase.
Should SMS Be Inside the Same Flow as Email?
Yes, in most cases. Building one flow with both channels lets you sequence them deliberately, for example email first and SMS as the final nudge, and it keeps consent and suppression logic in one place. Running parallel email-only and SMS-only flows for the same trigger usually produces duplicate messaging and makes attribution harder to read.
Why Is My Flow Showing Zero Recipients?
The usual causes are a trigger event that is not being sent by your store or site, messages left in Draft or Manual status after the flow was set live, or a filter that excludes nearly everyone. Check the flow analytics for entry volume first: if profiles are entering but nothing sends, the problem is message status or filters, not the trigger.
How Often Should Flows Be Reviewed?
Review revenue per recipient and conversion rate monthly, and audit the full flow logic quarterly. Catalogs change, discounts expire, and new flows start overlapping with old ones. A quarterly audit that removes expired offers, verifies triggers, and checks for message collisions typically recovers more revenue than building an additional flow.