Best tools to track user behavior and email users based on it (2026)

Track what users do and email them about it, with one tool or a pair: Behavly, PostHog, Customer.io, Clarity, Contentsquare, Mouseflow and Loops compared.

Updated October 10, 2026 · Competitor details checked October 10, 2026 on each vendor’s own site

Track and email users in one tool with Behavly, PostHog or Customer.io, or pair Clarity, Contentsquare or Mouseflow with an email tool such as Loops.

  • Behavly: best for SaaS teams that want tracking, heatmaps and emails written from each person’s activity in one tool.
  • PostHog: best for engineering-led teams that want analytics, session replay and event-triggered email in one product.
  • Customer.io: best when email, SMS, push and in-app matter more than analytics.
  • Microsoft Clarity: best free behavior tool to pair with an email tool.
  • Contentsquare (formerly Hotjar): best for UX research with recordings, heatmaps and surveys, next to an email tool.
  • Mouseflow: best for detailed heatmaps and form analytics, next to an email tool.
  • Loops: best email half of a pair for a small SaaS team.

One tool or two?

This decision comes before any product. An all-in-one tool watches what people do and sends the email from the same data. A pair splits the job: one tool shows you behavior, and another sends email from events you feed it.

One tool
One script, one profile per person, and the behavior you look at is the behavior that triggers the email. No plumbing between products, and one bill. The catch is that each all-in-one is weaker somewhere: Behavly has no recordings or SMS, PostHog wants events and templates set up by hand, and Customer.io doesn’t list heatmaps or replay.
Two tools
You get a specialist for each half, and the behavior half can be free. But they don’t share data by default. What you spot in a recording isn’t a trigger until you send that behavior to the email tool as an event. That means two scripts, two user IDs to keep in step, and two vendors to review.

A rough rule: if you mostly want to watch sessions and fix your UX, a pair works well. If you mostly want to act on behavior, one tool saves the plumbing.

How we picked

Each option had to cover both halves: seeing what signed-in users do, and emailing them because of it. For pairs, we chose behavior tools that can identify a signed-in user and an email tool that takes events from your app.

We left out Smartlook, which many 2026 lists still recommend. It has sold no new subscriptions since May 31, 2026, and shuts down on September 30, 2027.

Prices were read from each vendor’s own pricing page on October 10, 2026. Behavly is our product. It’s included because tracking and email in one tool is its whole design, and it’s held to the same standard as the rest, gaps included.

User tracking and email tools compared

ToolBest forStarts at (per month)Priced onWhat it tracksEmails users?
BehavlyOne tool, emails written per personFree (100 tracked contacts); paid from $79 (2,500)Tracked contactsPage views, clicks, movement and scroll per signed-in person; heatmapsYes, from your own mailbox
PostHogOne tool, engineering-led teamsFree monthly allowance per product, then usageEvents, recordings and messagesProduct events, session replay, heatmaps, surveysYes, through Workflows, from templates you write
Customer.ioOne tool, multi-channel messaging$100 (5,000 profiles)ProfilesEvents and attributes your app sendsYes, plus SMS, push, in-app and WhatsApp
Microsoft ClarityFree behavior half of a pairFree, no paid planNot pricedRecordings, heatmaps, rage and dead clicks, funnelsNo
Contentsquare (Hotjar)UX research half of a pairFree (up to 200,000 sessions); $39 billed yearlySessions and replaysRecordings, heatmaps, funnels, surveysNo
MouseflowHeatmap and form half of a pairFree (500 sessions); 25 billed yearly, currency not shownSessionsRecordings, six heatmap types, forms, funnelsNo
LoopsEmail half of a pairFree (1,000 newest contacts); paid from $49 (5,000)Subscribed contactsEvents you send itYes

Behavly: best all-in-one for SaaS follow-ups

Behavly, which we make, puts the tracking and the email in one place for SaaS teams. One script tag on your signed-in pages ties each visit to the person who was signed in, with no identify call. Someone who uses a laptop and a phone shows up once.

On the behavior side, heatmaps paint clicks, movement, scroll and per-element counts over your live site, for everyone or for one person. The Heatmaps page lists rage clicks and dead clicks with the people behind them. Insights covers audience, activity, a funnel and email results.

On the email side, Behavly finds groups by behavior, and an always-on Agent can branch on logins, page visits and actions you send with behavly.track. Each email is written for one person from their activity and sent from your mailbox. Replies come back with that history attached.

Where it’s strong
Seeing and acting in one place: open one person’s heatmap, then read the email written from that same activity. No event plan before the first campaign. Heatmaps are on every plan, Free included. IP addresses aren’t stored, and password forms are skipped. You approve the emails before they go out.
Where it falls short
No session recordings or surveys, and lighter analytics than PostHog. It’s built for signed-in users, not marketing-site traffic. Email only: no SMS, push or in-app. No transactional email or newsletters. Sending from your own mailbox suits one-to-one volume. Few integrations, and it costs more per contact than Loops or Bento.
Pricing
Free (100 tracked contacts, 30 days of behavior data, 50 AI-written emails a month). Starter $79/month (2,500 tracked contacts, 90 days, one Agent). Growth $249/month (10,000 tracked contacts, 180 days, five Agents). Scale $699/month, through sales.

PostHog: best all-in-one for engineering-led teams

PostHog is product analytics at its core, and also covers session replay, heatmaps, surveys, feature flags, experiments and error tracking. Its identify call merges a visitor’s anonymous history into their signed-in profile.

Workflows, generally available since December 30, 2025, sends email from your own verified domain when any PostHog event fires. Workflows add delays, audience splits and drip sequences, and can also send push, SMS, Slack alerts and webhooks.

Where it’s strong
The broadest tool here, with a monthly free allowance on every product: 1 million events, 5,000 web recordings, 1,500 survey responses and 10,000 workflow messages per channel. Any event you track can trigger a workflow. No credit card on the free plan.
Where it falls short
It’s built for engineers: you set up events and identify calls yourself. Emails are templates you write; the docs don’t say its AI writes them. The free plan keeps recordings for 1 month and collects heatmaps on 3 pages. Usage billing across products takes some estimating.
Pricing
Free up to each allowance, then pay as you go: from $0.00005 per event, $0.005 per recording and $0.003 per email, falling at volume. Pay-as-you-go keeps recordings for 90 days.

Customer.io: best all-in-one when messaging comes first

Customer.io is a messaging platform first. It collects events and attributes from your app through its SDKs, API, webhooks or Segment. Journeys act on them across email, SMS, push, in-app, WhatsApp and LINE.

That makes it one tool for the event data and the messages, but not for watching behavior. Its pages don’t list heatmaps or session replay. For teams that keep analytics elsewhere, it lists Mixpanel and Amplitude integrations.

Where it’s strong
Every channel on the entry plan, mature journey branching, and A/B and multivariate tests on all plans. It also works well as the email half of a pair.
Where it falls short
No heatmaps or replay listed, so you still need another tool to see why people stall. Engineers have to send the events. The $100/month entry counts every identified profile, and warehouse integrations need Premium.
Pricing
Essentials from $100/month (5,000 profiles) and $145 at 10,000. Premium from $1,000/month billed yearly. A 14-day trial.

Microsoft Clarity: best free behavior tool for a pair

Clarity is Microsoft’s free heatmap and recording tool, with no traffic limits. It has click, scroll, area and conversion heatmaps, always-on recordings, rage and dead click insights, funnels and Copilot summaries.

Its Identify API attaches your own user ID, hashed in the browser, so you can filter recordings and heatmaps to one person.

Where it’s strong
Free for unlimited sites, heatmaps and team members. Good at showing where people get stuck.
Where it falls short
Recordings are kept for 30 days and heatmap data for 9 months. No surveys are listed. Microsoft says it uses the behavioral data to improve its machine learning models, and never shares it with third parties. It doesn’t email anyone, so triggers must come from events you send your email tool.
Pricing
Free, with no paid plan.

Contentsquare (formerly Hotjar): best for UX research in a pair

Hotjar is now part of Contentsquare, and new Hotjar accounts can’t be created. Its recordings, heatmaps and funnels now live in Experience Analytics, and its surveys in Voice of Customer. Sense AI summarizes replays and heatmaps.

Where it’s strong
A very large free allowance: up to 200,000 sessions and 10,000 replays a month, with heatmaps, funnels and basic surveys. Surveys sit right next to the recordings.
Where it falls short
The free plan keeps 1 month of data. Tying sessions to a signed-in user with Contentsquare’s own identify call needs Product Analytics or an add-on, priced on request. It doesn’t email users.
Pricing
Experience Analytics Growth from $39/month billed yearly (7,000 sessions and replays), or $49 monthly. Voice of Customer Growth from $79/month billed yearly.

Mouseflow: best for detailed heatmaps in a pair

Mouseflow is recording and heatmap software for conversion work. It has click, scroll, geo, attention, movement and friction heatmaps, plus form analytics, funnels, journey analytics and feedback surveys.

Where it’s strong
The widest range of heatmaps here, form analytics, and unlimited users on every plan. A REST API and an MCP server.
Where it falls short
Identifying users is only on “select plans”, and Mouseflow doesn’t publish which. The free plan covers 500 sessions and 1 month of data. Funnels are capped by plan. It doesn’t email users.
Pricing
The page shows no currency. Essential is 25 a month billed yearly, or 39 monthly, for 5,000 sessions. Advanced is 109 a month billed yearly for 25,000. A 14-day free trial.

Loops: best email half of a pair

Loops is the simplest email tool to pair with any of the three above. A workflow can start on an event from its API, or from Segment, RudderStack or PostHog. So a team on PostHog analytics can pass its events to Loops through that integration.

Customer.io is the heavier choice for this half, if you need SMS, push or in-app as well.

Where it’s strong
Low, contact-based pricing with unlimited sends on paid plans. Transactional email included. Stripe, Segment, Zapier, Supabase and Clerk integrations. An API, a CLI and an MCP server.
Where it falls short
Email only, and no built-in AI writer is documented. It knows only the events you send it, so every trigger is something you instrument. Every subscribed contact counts toward the price.
Pricing
Free for your 1,000 newest contacts, up to 4,000 sends in any rolling 30 days. Paid from $49/month (5,000 contacts) and $99 (10,000).

How to connect a behavior tool and an email tool

If you go with a pair, plan the join before you install anything. The behavior tool tells you what to email about. The email tool acts only on events you send it.

  1. 1Install the behavior tool on your signed-in pages, and identify each user with the same ID your app uses.
  2. 2Watch recordings or heatmaps to find the moments worth an email, such as a setup step people abandon.
  3. 3Send each of those moments to the email tool as a named event from your app, or through Segment.
  4. 4Build the workflow in the email tool, with a wait and a branch on whether the person came back.
  5. 5Write the emails, then check the behavior tool after a few weeks to see whether the moment changed.

Fullstory is the behavior tool that passes signals on by itself. Its Activation feature streams behavioral signals to tools such as Braze, Intercom and Zapier. Its paid plans are priced on request.

How to choose

If you…Look at
Want to see behavior and send follow-ups from one SaaS tool, with no event setupBehavly
Have engineers and want analytics, replay, flags and email togetherPostHog
Need SMS, push and in-app, and will send events from your appCustomer.io, with Clarity for recordings
Want free recordings and heatmaps, and simple emailMicrosoft Clarity + Loops
Run UX research with surveysContentsquare + Loops or Customer.io
Optimize forms and sign-up pages in detailMouseflow + Loops
Want session recordings and per-person follow-upsBehavly + Microsoft Clarity

Whatever you choose, test it on one behavior first, such as people who signed up but never finished setup. If that email reaches the right people at the right moment, the rest is more of the same. The guide to users who never activated covers what to send them.

Questions

Is there one tool that tracks user behavior and sends emails?
Yes. Behavly tracks signed-in users with one script tag, shows heatmaps, and writes each follow-up from that person’s activity. PostHog combines analytics, session replay and heatmaps with Workflows, which sends email from templates you write. Customer.io collects the events your app sends and emails on them, but doesn’t list heatmaps or replay.
Can Hotjar or Microsoft Clarity send emails to users?
No. Clarity and Contentsquare, which Hotjar is now part of, record and report behavior but don’t email your users. To act on what they show, send the same behavior as events to an email tool such as Loops or Customer.io.
Should I use one tool or two for analytics and email?
Use one tool if acting on behavior is the main goal: one script, one profile per person, and no event plumbing. Use two if you want the strongest recordings or analytics and don’t mind sending events to a separate email tool. You can also run a free recorder such as Clarity next to an all-in-one.
Which of these tools identify signed-in users?
Clarity and PostHog have identify calls you add to your code, and PostHog merges anonymous history into the signed-in profile. Contentsquare ties its own identify call to Product Analytics or an add-on, and Mouseflow to select plans. Behavly detects the signed-in session on its own, with no identify call.
What is the cheapest way to track behavior and email users?
Microsoft Clarity is free, and Loops is free for your 1,000 newest contacts, so that pair costs nothing to start. PostHog’s free allowance includes 10,000 workflow messages per channel a month. Behavly is free for 100 tracked contacts, with heatmaps and 50 AI-written emails a month.