These tools often end up together
PostHog Workflows and Loops are not strict rivals. PostHog maintains a Loops destination that forwards events to trigger Loops automations and syncs person properties into Loops contacts. Plenty of SaaS teams run PostHog for analytics and Loops for email.
So the practical question is not "which one", but "do I need Loops yet, or can PostHog Workflows carry my email for now?"
When PostHog Workflows is enough
Early on, most product email is reactive. A user signs up, stalls or hits a milestone, and you want to say something. PostHog Workflows covers that without adding a tool:
- Setup nudges. Trigger on signup, wait a day, check whether the user completed the key action, and email only those who did not.
- Milestone messages. When a user creates their tenth project, send a note with an advanced tip.
- Team alerts. Post to Slack when a trial account from a target company becomes active.
You build these in PostHog's editor, personalize templates with person properties and verify your sending domain once. Opt-outs use message categories and a suppression list.
Signs you have outgrown it
The switch usually happens when email stops being a side effect and becomes a job:
- Someone wants to send a monthly product update to all users.
- You need password reset and receipt emails from the same system as lifecycle email.
- A founder or marketer, not an engineer, edits copy every week.
- You want to see every email a specific user received in one place.
PostHog Workflows can email a cohort, but it lacks the editor, audience management and transactional API that make ongoing email work comfortable. That is Loops' territory.
What Loops adds
Loops is a focused email tool for SaaS. You get a clean editor, an audience with contact properties and mailing lists, broadcasts, automated loops triggered by events or contact changes, and a transactional API for app-critical email. Paid plans have unlimited sends, no seat charges and sending speeds up to 1,000 emails per second.
The official bridge: PostHog's Loops destination
This pair has something most comparisons do not: a supported integration between them. In PostHog's data pipelines, you add a Loops destination with a Loops API key and choose one of two modes. "Send events" forwards chosen PostHog events to Loops to trigger automations. "Update contacts" creates or updates Loops contacts from PostHog person properties.
That makes a gradual migration realistic. You can keep internal alerts in PostHog, turn on the destination for the handful of events your email needs, and rebuild one customer-facing workflow at a time in Loops. The main thing to get right is identity: forward identified persons with an email property, and map only the properties your segments use.
Subscriber brackets and the dormant-user problem
The pricing tension here is what each tool counts. Loops counts subscribed contacts. PostHog counts emails sent.
A self-serve SaaS product often accumulates many signups who tried the product once and never returned. In Loops, every one of them who remains subscribed pushes you toward the next bracket. In PostHog, they cost nothing unless a workflow emails them. On the other hand, a small, engaged list that receives several emails a week gets unlimited sends in Loops, while PostHog charges for each one past 10,000.
Pricing reality in two scenarios
| Scenario | PostHog Workflows | Loops | Sequenzy |
|---|---|---|---|
| 30,000 signups, 8,000 lifecycle emails a month | Free (under 10,000 emails) | Depends on subscribed count; 10,000+ subscribers is above the $99 bracket | Free plan too small; $19 covers 15,000 emails |
| 4,000 engaged subscribers, 2 emails a week (about 32,000 a month) | 22,000 x $0.003 = about $66 | $49 (1,000 to 5,000 subscribers) | $49 covers 60,000 emails |
| 10,000 subscribers, 40,000 emails a month | 30,000 x $0.003 = about $90 | $99 (5,000 to 10,000 subscribers) | $49 covers 60,000 emails |
PostHog figures exclude your PostHog analytics bill. Loops figures assume a clean list; unsubscribed contacts do not count toward pricing.
Who writes the email
PostHog is a product analytics suite with Workflows as one of many products, and its email editor is functional rather than a writing environment. Loops is built for the person who writes email: a founder sending a product update, a marketer tuning onboarding copy. If the person who owns email rarely opens PostHog, putting their work there creates friction every week.
Review signals
Loops reviews on Product Hunt and independent review sites repeatedly praise its clean interface, fast setup, straightforward workflow building, documentation and responsive support. The common criticisms are that simplicity sometimes means missing features, some reports of editor bugs such as no undo, and costs that climb at large subscriber counts. Independent reviews of PostHog Workflows specifically are still limited because it is newer.
Use-case matchups
| Need | Better fit | Why |
|---|---|---|
| A few activation nudges from PostHog cohorts | PostHog Workflows | No second tool or data sync |
| Monthly product update to all users | Loops | Broadcasts and editor are built for it |
| Password resets and receipts | Loops | Transactional API included on paid plans |
| Slack alert on a high-intent trial | PostHog Workflows | Loops is email only |
| Trial-ending emails based on Stripe status | Sequenzy | Billing sync is native |
Where Sequenzy fits
Sequenzy is the same category of tool as Loops: a SaaS email platform with broadcasts, automated sequences and transactional email. The differences are specific. Sequenzy syncs Stripe, Paddle and Polar, so billing moments trigger emails and revenue can be attributed to them. Its PostHog integration receives live events through a PostHog destination and can import recent history, so a new sequence can target behavior from before you connected. It charges by emails sent with unlimited contacts: free for 2,500 a month, $19 for 15,000, $29 for 30,000 and $49 for 60,000. It also drafts sequences with AI and exposes email operations through API, CLI and MCP.
Loops still wins on a more generous free contact allowance, unlimited sends on paid plans, an editor many founders like and a longer track record in the SaaS community.
Migration checklist
| Workstream | PostHog Workflows to Loops | Loops to PostHog Workflows |
|---|---|---|
| Contacts | Enable the destination in update-contacts mode or import CSV | Ensure each Loops contact is an identified PostHog person |
| Events | Enable send-events mode for the events loops need | Confirm the events exist in PostHog |
| Workflows | Rebuild as Loops automations; keep Slack and webhook steps in PostHog | Rebuild loops as workflows |
| Templates | Paste content into the Loops editor | Export HTML and recreate in the content library |
| Unsubscribes | Import opted-out users before the first send | Import Loops unsubscribes into PostHog's suppression list |
| Transactional | Move app emails to the Loops transactional API | Keep transactional email in a dedicated sender; PostHog is not built for it |
| Domain | Add Loops DNS records | Verify your domain in PostHog |
Decision checklist
- Choose PostHog Workflows if you need a few nudges, live in PostHog and send under 10,000 emails a month.
- Choose Loops once someone writes and schedules email regularly and you want transactional and marketing email in one simple tool.
- Avoid Loops if most of your subscribers are dormant signups you rarely email.
- Avoid PostHog Workflows as your transactional sender.
- Consider Sequenzy if billing events are central or your list is growing much faster than your sends.
