# Behavly vs Customer.io

> Customer.io is a multi-channel platform your team designs and writes; Behavly is an AI agent that writes each follow-up per person. Features, prices, verdict.

Source: https://behavly.io/compare/behavly-vs-customer-io · Updated October 10, 2026 · Competitor details checked October 10, 2026 on each vendor’s own site

Customer.io is a full multi-channel engagement platform (email, SMS, push, in-app and WhatsApp) where your team designs the journeys and writes the messages. Behavly is an AI agent that tracks your signed-in users and writes each follow-up email for one person from what they did. It sends from your own mailbox.

Behavly is our product, so we’ve kept to facts you can check on both sites.

#### The short answer

##### Choose Customer.io if…

- You need SMS, push, in-app messages or WhatsApp alongside email.
- You send transactional email or high volume. Both are covered on Essentials, which includes 1M emails a month.
- You have engineers or a data team to send events in through its SDKs, API, webhooks or Segment.

##### Choose Behavly if…

- You want each follow-up written for one person, from what they did in your product.
- You’d rather add one script tag to your signed-in pages than build an event pipeline.
- You want email from a real mailbox, with replies and each sender’s activity in one inbox.

#### Behavly vs Customer.io at a glance

|  | Behavly | Customer.io |
| --- | --- | --- |
| **Pricing starts at** | Free (100 tracked contacts); Starter $79/month (2,500 tracked contacts) | $100/month (Essentials, 5,000 profiles), billed monthly |
| **Priced on** | Tracked contacts, with a monthly allowance of AI-written emails | Profiles: every identified person and object. Extra emails $0.12 per 1,000; AI credits $10 per 100K |
| **Free plan** | Yes, with no time limit (100 tracked contacts, 50 AI-written emails a month) | No. A 14-day trial capped at 5,000 messages, and a free year for startups that raised under $10M |
| **Channels** | Email | Email, SMS, push, in-app, WhatsApp and LINE, on every plan |
| **Behavior tracking** | One script tag records page views, clicks, pointer movement and scroll depth for signed-in users, with no identify call; product actions via `behavly.track` | Pre-built integrations, APIs, SDKs (mobile SDKs for iOS, Android, React Native, Flutter and Expo) and webhooks; Segment as source and destination |
| **Heatmaps** | Yes: four layers painted on your live site, for everyone or one person, on every plan | Not listed on the pages we checked |
| **Journey builder** | Agent paths built from blocks or described in words; waits and branches on opens, clicks, logins, page visits, replies and product actions | Visual workflow builder with True/False, Multi-Split and Random Cohort branches |
| **Who writes the emails** | Behavly writes each email for one person from their activity, or sends your own copy or template unchanged | Your team; the AI Agent (beta) helps draft and refine |
| **Languages** | Writes in any of 80 languages, per recipient | An AI message translator in Design Studio |
| **Sends from** | Your own mailbox over IMAP/SMTP (Gmail, Outlook, Zoho or a custom host) | Customer.io’s infrastructure on your sending domain, or up to six SMTP servers of your own (such as SendGrid, Mailgun or Amazon SES) |
| **Transactional email** | Not offered | Included on every plan |
| **Integrations** | Its own snippet, a REST API and an MCP server; no native Stripe, Segment, HubSpot or Zapier connection | Segment, Mixpanel, Amplitude, webhooks and an MCP server; HubSpot, Salesforce, Snowflake, BigQuery and Redshift on Premium and Enterprise |
| **A/B testing** | On any Agent email step (Starter and up), judged on the path’s goal | A/B and multivariate testing on every plan, plus Random Cohort branches |
| **AI features** | Per-person email writing, plain-language audiences, paths built from a description, a weekly path review, AI reply drafts, AI email designs from your brand | AI Agent (beta), LLM actions in journeys, send-time optimization, AI segment builder, AI styles, translation and content analysis |
| **Approval before sending** | On by default for one-time campaigns; an optional hold on Agents | Not covered on the pages we checked |
| **Seats** | 1, 3, 10 or unlimited, by plan | Unlimited on every plan |

#### How each one works

##### Customer.io

You send people and events into Customer.io through its SDKs, its API, webhooks or Segment. Your team builds journeys in a visual workflow builder, with True/False, Multi-Split or Random Cohort splits. It also writes the messages for each channel: email, SMS, push, in-app, WhatsApp or LINE.

The AI Agent, in beta on every plan, can draft and refine messages within your brand voice and guardrails. It can also build journeys from a conversation, and on Essentials it comes with three custom skills and one weekly routine. Journeys can include LLM actions, and there’s an AI segment builder and send-time optimization.

Email goes out from Customer.io’s infrastructure on your sending domain, or through SMTP servers of your own.

##### Behavly

You add one script tag to your site and your signed-in app. From then on, each person’s activity collects on a single profile, merged across their devices, with no identify call. Product actions can be added with `behavly.track`.

Next you pick who to follow up with: a group Behavly detected, or one you describe in plain language, seeing who’s in it before it’s saved. For a single send, that’s a one-time campaign. For something ongoing, you write the path out in words and a [Behavly Agent](https://behavly.io/help-center/campaigns/behavly-agents) turns it into emails, waits and branches.

Day to day, each person moves through the path on their own clock, starting the moment they qualify. A path might send a welcome note, then branch on whether they log in within three days. Branches can also check whether they opened the previous email or replied.

When someone reaches an email step, Behavly writes it from their own activity, in their language. If you’ve turned on the approval hold, it waits until you read and release it. Then it goes out from your own mailbox. Replies land in Behavly’s inbox with what the sender did on your site shown alongside.

#### More reasons to choose Customer.io

- Your data lives in Segment, a mobile app or, on Premium, a data warehouse.
- You want password resets and receipts to come from the same tool as your lifecycle email.
- You want A/B and multivariate testing across whole journeys, on every plan.
- Your team wants to design every journey and write every message, with unlimited seats.
- You’re a startup that raised under $10M and qualifies for the free year of its Startup Program.

#### More reasons to choose Behavly

- You’d rather describe a path in a sentence than wire one up step by step.
- Your users read different languages: each email can be written in any of 80, with no variants to write yourself.
- You want heatmaps and each person’s activity in the same tool as your email.
- You want to start without product events and add them with `behavly.track` later.
- You want to read the emails before they go out.

#### Price at the same audience size

Both price on the size of your audience, but they count different things and include different things. Customer.io counts profiles, meaning every identified person and object, and Essentials includes 1M emails a month. Behavly counts tracked contacts and includes a monthly allowance of emails it writes for you.

| Audience | Behavly | Customer.io (Essentials) |
| --- | --- | --- |
| 2,500 contacts | $79/month (Starter): 2,000 AI-written emails a month, 1 mailbox, 3 seats, 1 Agent | $100/month: up to 5,000 profiles, 1M emails a month, every channel, unlimited seats |
| 5,000 contacts | $249/month (Growth, since Starter stops at 2,500): up to 10,000 tracked contacts, 8,000 AI-written emails a month, 3 mailboxes, 10 seats, 5 Agents | $100/month: 5,000 profiles |
| 10,000 contacts | $249/month (Growth) | $145/month: 10,000 profiles |

Customer.io costs less at every size here, and includes far more sending volume and every channel. Further up, Customer.io’s Essentials is $235/month at 20,000 profiles and $415/month at 40,000. Behavly’s Scale plan is $699/month for 40,000 tracked contacts.

What Behavly’s price includes that Customer.io’s doesn’t is the writing. Each email is composed for one person from their activity. On Customer.io, that’s work your team does, with the AI Agent’s help.

#### Using both, or switching

The two overlap less than the table suggests, and running both can make sense. Keep Customer.io for transactional email, SMS, push and broadcasts to your whole list. Use Behavly for follow-ups that should read like a note from a person. Think of a stalled setup, a second visit to the pricing page, or a regular user who has gone quiet.

If you do, decide which tool owns each flow so nobody gets two emails about the same thing. Behavly doesn’t read Customer.io’s data; it needs its own snippet on your signed-in pages.

If you switch, contacts can be imported from a CSV. Behavior history, though, starts when the Behavly snippet first sees each person. Imported contacts appear straight away, without activity, until they next visit.

Let the snippet run for a few weeks before you turn off the Customer.io journeys it replaces. That way the first emails have something to be written from.

## Questions

### Is Behavly cheaper than Customer.io?

Not at the same audience size. Customer.io Essentials is $100/month for up to 5,000 profiles and $145/month at 10,000. Behavly is $79/month for 2,500 tracked contacts and $249/month for 10,000. Behavly has a free plan (100 tracked contacts, no time limit); Customer.io has a 14-day trial and a free year for startups that raised under $10M.

### Does Behavly send SMS or push notifications?

No. Behavly sends email only, from your own mailbox. Customer.io includes email, SMS, push, in-app, WhatsApp and LINE on every plan.

### Can Behavly send transactional email like password resets?

No. Behavly has no transactional email API. Customer.io includes transactional email on every plan.

### Does Customer.io write emails with AI?

Its AI Agent, in beta on every plan, helps draft and refine messages within your brand voice and guardrails. It can also build journeys from a conversation, and journeys can include LLM actions. Your team still designs the journeys and owns the copy. Behavly writes each email for one person from that person’s activity.

### Can I use Behavly and Customer.io together?

Yes. A sensible split is Customer.io for transactional email, SMS, push and broadcasts, and Behavly for follow-ups written per person from product activity. Decide which tool owns each flow so nobody gets two emails about the same thing.

## Related

- [Customer.io alternatives for SaaS teams in 2026](https://behavly.io/compare/customer-io-alternatives)
- [Behavly vs Loops](https://behavly.io/compare/behavly-vs-loops)
- [What is behavioral email? A practical guide for SaaS](https://behavly.io/guides/behavioral-email)
- [Trial-to-paid emails: what to send during a free trial, based on usage](https://behavly.io/guides/trial-to-paid-emails)