Head to head
SendHeronvs
Customer.io
SendHeron vs Customer.io
A cross-channel messaging platform priced on profiles against a lifecycle email tool priced on contact tiers. Customer.io does far more; SendHeron does the email part for a fifth of the price, from an EU company, and drafts the suite for you. Which is right depends on how much of the platform you would use.
Customer.io's prices are as of September 22, 2026, from its own pricing page.
Quick comparison
| At a glance | SendHeron | Customer.io |
|---|---|---|
| Best for | SaaS teams whose messaging is email, who want the lifecycle suite drafted, with contact data in the EU | Teams that need push, in-app, SMS or WhatsApp beside email, an object data model, and enterprise support |
| Starting price | €19/mo (Starter, 10,000 contacts, 50,000 emails a month) | $100/mo (Essentials, 5,000 profiles, 1 million emails, billed monthly) |
| Billed on | Subscribed contacts, with a pooled monthly send allowance | Profiles, people and objects together; $0.009 per extra profile, $0.12 per extra 1,000 emails |
| Free plan or trial | 7-day free trial, 1,000 contacts and 5,000 sends, card at checkout | No free plan; a year free through the startup program if you have raised under $10M |
| Data residency | EU company; contact data stored in Germany | US or EU data center, chosen at signup, on every plan |
Channels and reach
This is the table Customer.io wins outright, and it is first for that reason. SendHeron is email only; if a second channel is a requirement, the rest of this page is academic.
| Feature | SendHeron | Customer.io |
|---|---|---|
| Yes | Yes | |
| Push and in-app messages | no | Unlimited monthly push and in-app, mobile SDKs |
| SMS | no | Custom-priced sends |
| WhatsApp and LINE | no | Included |
| Webhooks, send and receive | Not in the API reference | Unlimited |
| Anonymous messages | no | Premium and Enterprise |
Lifecycle automation
Both have a visual builder with branches. The difference is the starting point: Customer.io's agent builds campaigns from a prompt against the data already in your workspace; SendHeron's setup starts from your website and drafts a suite before any data exists.
| Feature | SendHeron | Customer.io |
|---|---|---|
| Visual workflow builder with delays and branches | Yes | Yes |
| A lifecycle suite drafted from your website at setup | Yes, as drafts you approve | AI agent builds campaigns from a prompt, in product |
| Conditions with AND and OR over tags and properties | Yes | Segments and attributes |
| Send-time optimisation | no | Yes |
| A/B and multivariate testing | no | Yes |
| Enroll, pause, resume and bulk-enroll over the API | Yes | API-triggered broadcasts, unlimited API calls |
| Per-step statistics on a sequence | Yes | Campaign reporting and dashboards |
Data model
Customer.io models people and objects and everything that relates them. SendHeron models contacts with tags and properties, and separates products by workspace rather than by object.
| Feature | SendHeron | Customer.io |
|---|---|---|
| People with attributes | Contacts with properties | Unlimited attributes |
| Objects (companies, accounts, anything you define) | no | 2 object types on Essentials, 10 on Premium |
| Segments | Rules over tags and properties, no separate list to sync | Segments, AI segment builder, suggested segments |
| Several products under one subscription | Workspaces; unsubscribes per project, bounces account-wide | Two workspaces on Essentials, billed together |
| Reverse ETL | no | Yes |
| Data warehouse destinations and data replay | no | Premium and Enterprise |
API, security and hosting
Both can keep contact data in the EU, which is rarer in this category than it should be. Customer.io offers it as a choice; SendHeron offers nothing else.
| Feature | SendHeron | Customer.io |
|---|---|---|
| REST API on every tier | Yes | Unlimited API calls on every plan |
| Where contact data is stored | Germany; EU company | US or EU data center, chosen at signup, every plan |
| Published sub-processor list and DPA on request | Yes | GDPR listed on the pricing page |
| HIPAA | no | Premium and Enterprise |
| Audit logging and dedicated hardware | no | Enterprise |
Plans and billing
| Feature | SendHeron | Customer.io |
|---|---|---|
| Entry price | €19/mo for 10,000 contacts | $100/mo for 5,000 profiles |
| What is billed | Subscribed contacts; unsubscribed and bounced stored free | Profiles, people and objects together |
| Emails included | 50,000 a month on Starter, pooled | 1 million a month on Essentials |
| Overage | Transactional up to 10% past the pool; the next tier for more | $0.009 per profile, $0.12 per 1,000 emails |
| Next tier up | €49/mo (Growth, 40,000 contacts) | $1,000/mo billed yearly (Premium) |
| Free plan | no | No; twelve months free through the startup program if you have raised under $10M |
| Trial | 7 days, 1,000 contacts and 5,000 sends, card at checkout | Not stated on the pricing page |
Pricing comparison
Customer.io's Essentials price is a floor with a per-profile overage above it; SendHeron's tiers are flat. The rows below put the two side by side at the sizes a small SaaS actually reaches.
| Scenario | SendHeron | Customer.io |
|---|---|---|
| 5,000 contacts, 25,000 emails a month | €19/mo (Starter) | $100/mo (Essentials) |
| 10,000 contacts, 50,000 emails a month | €19/mo (Starter, at its ceiling) | About $145/mo (Essentials plus $0.009 per extra profile) |
| 40,000 contacts, 150,000 emails a month | €49/mo (Growth) | About $415/mo on the overage rate, or a Premium quote |
SendHeron prices in EUR, VAT included where it applies; Customer.io in USD, billed monthly on Essentials. The Customer.io figures above 5,000 are arithmetic on its published $0.009 per additional profile, not quotes, and they assume every profile is a person: objects count too. Customer.io's 1 million included emails dwarf the scenario; SendHeron's rows assume sends within the tier's pool.
Strengths at a glance
Where Customer.io wins
- 01Every channel. Push, in-app, SMS, WhatsApp and LINE from the same workflow as the email, with mobile SDKs. SendHeron is email only, and that is the whole comparison for a team that needs a second channel.
- 02Objects. Companies, accounts and anything else you define, related to people, segmented and triggered on. SendHeron has contacts, tags and properties.
- 03A choice of data center. US or EU, on every plan, chosen at signup. SendHeron has no US option: contact data is stored in Germany, which is the right answer for a European buyer and the wrong one for a US company with US buyers.
- 04Enterprise depth. HIPAA on Premium, dedicated hardware, audit logging, a customer success manager and a shared Slack channel on Enterprise, and 1 million emails a month included from the first tier.
- 05Testing and optimisation. A/B and multivariate testing, send-time optimisation, conversion tracking and reverse ETL on every plan.
- 06The startup program. Twelve months free for companies that have raised under $10M, which is the most generous offer in the category.
- 07A bigger company. 9,000 brands on its pricing page. SendHeron's proof is one production customer, PostFast, whose lifecycle email it has run since day one.
Where SendHeron wins
- 01Price. Starter is €19 a month for up to 10,000 subscribed contacts; Customer.io is $100 for 5,000 profiles and about $145 for 10,000 on its overage rate. The next tier up is €49 against $1,000 billed yearly.
- 02The suite is drafted from your website, and a person approves it. Customer.io's agent builds campaigns from a prompt against the data you already have. SendHeron's setup reads the site, proposes the tag schema, drafts welcome, trial, win-back and cancel-save, and activates nothing until you do.
- 03Only subscribed people are billed. Unsubscribed and bounced contacts are stored free. Customer.io bills every profile, and an object is a profile.
- 04Size. A product a founder runs in an afternoon, with every feature on every tier. There is no $1,000 step, no yearly commitment, and no feature matrix to read.
- 05Scoped keys. 12 scopes, so a key that reads contacts cannot send. Customer.io's API is unlimited; its scoping was not readable from the pricing page.
- 06One allowance, and transactional never stops. Marketing and receipts share one pool, one reputation and one suppression list, and transactional mail keeps flowing up to 10 percent past a spent pool.
- 07Free deliverability tools. SPF, DKIM and DMARC checkers, a DMARC record generator and a deliverability test, with no account.
Which tool is right for you?
Choose Customer.io if:
- You need push, in-app, SMS or WhatsApp in the same journey as email
- Your data has companies or objects that people belong to, and your segments depend on them
- You need HIPAA, dedicated hardware, audit logging or a customer success manager
- You want a US data center as well as an EU one
- You have raised under $10M and can take the year free
Choose SendHeron if:
- Your messaging is email and you are paying a platform price for one channel
- Your lifecycle suite is unbuilt and you would rather approve drafts than design from scratch
- Your customer data has to be stored in the EU and you want that to be structural
- You want €19 a month to cover 10,000 subscribed contacts, with unsubscribes stored free
- You run several products and want one subscription with a workspace each
Switching from Customer.io to SendHeron
Export people from Customer.io with their attributes, then upsert each contact over SendHeron's API with the tags your sequences will trigger on; the Node SDK wraps the calls and the API reference states the rate limits. Customer.io attributes become SendHeron properties; the events your product sends become tags or tracked events, whichever your sequences branch on. Anything modelled as an object has to be flattened onto the person, because SendHeron has no objects, and this is the step to think about before anything moves.
Load your unsubscribes as suppressions before anything sends; a suppressed address is refused at send time with a stable reason you can read back. Templates paste in as HTML from Customer.io's code editor, and you can keep them as HTML or rebuild them in the block builder.
Campaigns are rebuilt, because the two tools model branching differently. Paste your website URL, edit the proposed tag schema, and read the drafted suite before you activate anything; we help map your journeys onto it during onboarding. Anything Customer.io was sending by push, SMS or WhatsApp needs another home, and SendHeron is not it.
Weighing more than these two?See every Customer.io alternative
Frequently asked questions
Learn more
- The REST API, scopes and rate limits
- Scriptable by agents
- Transactional and marketing on one account
- The API reference
- GDPR, data residency and the sub-processor list
- Roles and permissions
- Loops vs Customer.io for SaaS
- SendHeron pricing, with the competitor comparison
- How the visual sequence builder works
- Tags and segments
- EU data residency, and what we can and cannot prove
Compare other platforms
The same figures, from another vendor's side.
- AlternativesLoops alternatives10 tools compared at 5,000 contacts.
- AlternativesCustomer.io alternatives10 tools compared at 5,000 contacts.
- AlternativesPlunk alternatives10 tools compared at 5,000 contacts.
- AlternativesSequenzy alternatives10 tools compared at 5,000 contacts.
- Head to headSendHeron vs LoopsSendHeron vs Loops at 5,000 and 10,000 contacts: €19 a month on SendHeron Starter against $49 and $99 on Loops, with feature tables and where each one wins.
- Head to headSendHeron vs PlunkSendHeron vs Plunk: €19 a month with 50,000 emails included on SendHeron Starter against $0.001 an email with unlimited contacts on Plunk, with feature tables and where each one wins.
- BlogLoops vs Customer.io for SaaSA longer read from the SendHeron blog.
- Every comparison, in one place/alternatives
Customer.io's name and logo are trademarks of its owner, shown to identify the product compared. Live pricing drifts, so confirm on the vendor's site before you commit.