Customer.io Reviews 

Stay away from this app! they will steal your money, deny that they even charged you, run around in circles and then finally admit that they were charging you for simply installing the app on a free plan. These guys are thieves and the app does not wokr!

We were an active customer leveraging this product. We ran into bugs in their system when copying campaigns over per their AI assistants recommendations.

They copied the campaigns over but had a bug publishing the email body. Therefore our campaigns emailed EVERYONE we needed to follow up with an email with a subject but no body text, even though the UI showed a body text. When we went to try and click publish of any kind it said there was some kind of bug.

We alerted support, we requested help, we were informed NO ONE will be getting on a support call with us to confirm and help trouble shoot the bug they confirmed existed.

Definitely beware using this company, as any corporation where customer support in writing will put they won't meet with you is a joke.

Their support is extremely fast, capable, and helpful. The product adds new features and gets improved very often. Significantly superior than most slow-moving competitors.

I tried contacting the customer.io support team regarding a scammer that uses their services. The response that i got was:

"Customer.io is not in a position to independently verify or determine whether a company's business practices, billing practices, or subscription model are deceptive."

Based on this response, I come to a conclusion, that if you're in the scamming business, Customer.io would be a perfect fit for you!

What I liked:
Clean and nice UI fro workflows and campaigns, vivid results of A/B testing, not bad email templates editors
What I felt unhappy with:
Email; can be sent only through transactional/campaigns, we can not send a single email (if we want hyper-personalization) - and we need to track its status.
In html editor, it's hard to make out how to use urls - sometimes it's curly braces, sometimes it's not, and there is no clear guide about it

One of the worst companies we've ever dealt with. They've been billing us nearly USD$2,000 per month and refuse to provide phone support or respond to billing related emails. Strongly avoid, much better options exist such as react email, and your own email server or resend, and others.

Absolutely horrendous. The emails don't save, get sent at the wrong time and it freezes in between and restarts. They charge $425 a month for this horrible product, and dont even offer compensation. "Oh you can just send a correction email" - to 5000 people!

Good for journey orchestration, but UI has a bit of complexity

Amazing piece of software! We have nearly 300k users and it’s the highest value software we use - from push notifications, emails, sms, in app pop ups, in app banners, etc. this handles all of it with limited need for engineering resources, and at a reasonable price.

Renewal terms were changed without a proper notification! they tried a sneaky way to add conditions to the renewal contract, and increased their pricing.
they are not flexible at all on those terms even though we are their customers for many years. Feels like they don't care at all about their customers and their needs.
In addition to that - the product wasn't improved at all in the recent years. there are much better value-for-money options in the market.

After months of trying to make Customer.io work for our business, I can say with confidence: unless you have a dedicated engineering team and endless patience, look elsewhere.

On the surface, Customer.io sells you a dream — a powerful, flexible platform to automate your customer journey and deepen engagement. In reality? It’s a labyrinth of confusing UI, half-baked features, and support that ranges from indifferent to nonexistent.

1. UI/UX: Painful, Clunky, and Counterintuitive
The interface feels like it was designed by engineers for engineers, with no consideration for actual marketers. Simple tasks like segmenting users or editing workflows are buried under layers of clicks. Expect to waste hours navigating menus and hunting for where basic features live. And don’t even think about letting junior team members near it — the learning curve is brutal.

2. Integration? More Like Frustration.
The promise of “easy integration” is laughable. Their documentation is dense and often outdated, and their idea of “plug and play” means your devs will be tied up for weeks. We burned valuable time just trying to get data flowing properly — only to end up with a system that still doesn’t sync reliably.

3. Customer Support: MIA
The irony of a company that markets “customer engagement” and offers zero meaningful support is not lost on us. When things break — and they will break — good luck getting help. Tickets go unanswered, live chat is a joke, and “customer success” is an empty buzzword.

4. Inflexible Workflows, Overhyped Personalization
The workflow builder looks sleek, but don’t be fooled — it’s rigid and buggy. Want to trigger a journey based on a nuanced behavior? Be prepared to write custom code. Personalization options are technically there, but they’re clunky to use and often just don’t work. You end up testing endlessly just to make sure your emails don’t go out with empty fields.

5. Value for Money: Questionable at Best
For a tool that promises to be a “customer engagement platform,” the ROI just isn’t there. Between the time spent trying to get it to work and the patchy results it delivers, Customer.io ends up being more of a liability than a solution.

Bottom Line:
Customer.io might be right for tech-heavy teams who can dedicate serious dev hours to babysit the platform. But for most businesses looking to move fast and engage meaningfully with their audience? It’s a costly mistake wrapped in good branding. Proceed with caution.

Customer.io is a solid platform for email and messaging automation, offering a lot of flexibility and customization. The segmentation and workflow builder are powerful, making it great for targeted campaigns. However, the UI can feel a bit clunky at times, and there’s a learning curve to fully unlock its potential. Support is generally helpful, but response times can be slow. Overall, a strong tool for lifecycle marketing, but there’s room for refinement.

We've been with Customer.io for over 10 years (July 2014 to November 2024) and deeply regret ever doing business with them.

Moving email sequences to another provider is painful and costly, Customer.io know this and they fully take advantage of it. Every five-years or so Customer.io almost double their prices, the massive price increase is imposed on you (no grand fathering) and they don't care if the new pricing works for you as a business.

From a product point of view, we reviewed the major alternatives to Customer.io before migrating out, and I can say that there's nothing Customer.io does that their competitors don't do (most of the time for cheaper given that email marketing automation is a commodity nowadays).

We've been able to reduce our costs by >3x by moving out, the new tool we've selected also offers additional functionalities that will enable us to also remove our ticketing software leading to additional savings. Oh and contrarily to Customer.io, our new provider doesn't charge by profile so we will also save time by not having to remove profiles every month to try to save on cost.

All in all:
- if you're considering Customer.io: run you'll find much better elsewhere
- and if like us you're a customer of theirs unhappy with their prices and wondering if it's worth moving out: it is! The grass is much greener on the other side.

Hope this helps

Being super slow. We are trying to build in a new CRM system. We are comparing Customer.io and one of their big competitors. We are ready to go and have been chasing for over a week to get a quote.

Think we are going to have to go with the competitor because we can't get an answer about how much it costs...

Not a fan of customer io. It is way to expensive, but more importantly the pricing doesn't make any sense. The interface is less than ideal. They request annual contracts.

Incredible customer support!

The customer support team at customer.io is incredible. They are prompt, kind, efficient, and literally go out of their way to figure out the answer to your questions. One person even recorded a Loom for me, and did tests on Zapier to help diagnose the problems!

We've had an incredibly frustrating experience with Customer.io, and I feel compelled to share it with others. We've been using their platform for push notifications, but the results have been nothing short of disappointing.

First and foremost, the delivery rate of push notifications hovers at an abysmal 10-20%. This is completely unacceptable for a service that promises effective communication with our audience. Even worse, the push notifications are often sent with a significant delay, sometimes taking up to 45 minutes to reach recipients. This lag severely affects our ability to engage with our customers in a timely manner.

What's equally frustrating is the lackluster support we've received. Despite our repeated attempts to seek assistance, Customer.io's support team has been unable to resolve these critical issues. We've reached a point where we're essentially left to fend for ourselves with a malfunctioning service.

Adding insult to injury, Customer.io's management has shown no willingness to offer any kind of compensation or discount for the troubles we've encountered. It's incredibly disheartening to see a company not taking responsibility for their promises and failing to acknowledge their shortcomings.

To make matters worse, our integration costs with Customer.io were prohibitively high. We invested a substantial amount of time and resources into this platform, only to be met with a myriad of problems and unsatisfactory results.

If I had the chance to turn back time, I would undoubtedly choose a different service provider. Customer.io has left us deeply dissatisfied, both with their product and their customer support. I hope that by sharing our experience, others can avoid the same pitfalls and frustrations we've endured.

As a customer of Celsius Network, they used Customer.io to manage contacts. Unfortunately Customer couldn’t handle this responsibility and an employee store their data and shared it with an unauthorized third party.

Scam,

Charged us for inactive users! and even user without emails!!!
Also we removed them from our code base, but they were keep creating new profiles and charged us for that.

[EDIT 2022/07]: their email support is helpful so my original review was too harsh. that said, there's a lot of features still missing that are standard in other email tools.

ORIGINAL REVIEW:
their only form of customer support is email and it takes them 24+ hours to reply. debugging is a very slow.

they should at least open live chat but allowing for limited use of zoom or calls would be delightful.

if you are only going to have emails, make sure your support team is responding within hours, not a day or so.