• $40/month per seat
  • Highly available and scalable in the cloud as a fully managed service
  • Always on the latest stable version with same-day urgent bug fixes
  • Automated backups and same day support
  • Instant delivery of inbound mail
  • Highly deliverable, high-volume outgoing mail
  • Easily test incoming and outgoing email with preconfigured mailboxes
  • Use your own domain name
  • 10% discount for annual payments
  • Enterprise options available


  • $30/month per seat (billed annually)
  • Self-hosted on your hardware
  • We'll send you a free 3-seat license to get started
  • Your license never expires for versions released during your software updates term
  • Includes 100% of our source code from GitHub
  • Requires PHP 7.0+ and MySQL 5.6+
  • You're responsible for installation, upgrades, scaling, monitoring, security, and backups
  • Ideal for regulatory compliance (HIPAA, Safe Harbor, Sarbanes-Oxley)
  • 20% discount for timely renewals
  • Free 3-seat starter license (w/o updates)

FAQ: Cerb

What are seats?

Seats determine the maximum number of workers who can use Cerb at the same time.

For example, a team of 30 workers who are evenly split into three, non-overlapping shifts (morning, day, night) would only require 10 seats. That’s the highest number of workers who would ever be logged in at the same time.

You aren’t paying per worker account, so there isn’t a penalty for inviting everyone to participate: full-time staff, part-time contributors, busy executives, interns, temps, contractors, partners, and volunteers.

FAQ: Cerb Cloud

What is Cerb Cloud?

Cerb Cloud is a subscription-based service that provides a finely tuned, ready-to-use instance of Cerb in an ideal environment. All you need is a web browser and your team can start putting Cerb’s tools to work. We’ll handle everything else.

  • Fully managed: We install Cerb and its dependencies in an ideal environment, apply updates and security patches, monitor and scale the infrastructure, optimize performance, maintain backups, interface with email service providers for deliverability, provide application support and other technical services, and everything else. You can focus on what you do best.

  • Highly available: Failed components are automatically replaced and redundant capacity allows your service to continue uninterrupted. The Enterprise tier provides a database cluster with near-instant automated failover, and the other tiers recover from database failures automatically within minutes.

  • Scalable: Your Cerb environment can scale seamlessly from a single worker who sends a couple of messages per day, to hundreds of concurrent workers with a history spanning millions of conversations. Resources can seamlessly “scale up” and “scale out”. New resources are automatically provisioned and added to load balancers in response to traffic needs (web servers, cache servers, incoming and outgoing mail servers, etc).

  • High performing: Cerb is already designed to be fast and efficient. Cerb Cloud further accelerates performance by optimizing the underlying infrastructure and taking advantage of distributed services in the cloud. The database is continuously tuned for your workload. Resource requests (images, scripts, stylesheets, and fonts) are served instantly from a memory cache. Frequently accessed application data is retrieved from a memory-based cache cluster to reduce database latency. Background jobs are managed by an automated scheduler.

  • Secure: All traffic between you and your Cerb instance is encrypted with SSL. We support “Perfect Forward Secrecy”, which is a strategy that protects your past encrypted transmissions even if they are intercepted and recorded (even we can’t decrypt them once your session ends). Our resources operate in a “private cloud” with private networks for traffic between components, and firewall rules in front of public components that expose a minimally necessary attack surface. Our own access to those resources requires RSA keys and two-factor authentication.

  • Durable: We archive a sequence of full daily database backups, as well as the incremental point-in-time changes in between. Long term object storage (like attachments) are redundantly stored in several geographically separate locations. We can also arrange for backups to be routinely transfered to you.

How much does Cerb Cloud cost?


$40/month per seat
Features include:
  • Everything Cerb has to offer:
    collaborative workspaces, bot automation, etc
  • High availability w/ redundancy
  • Automated scaling
  • Automated backups
  • Mandatory SSL encryption
  • Instant delivery of inbound mail
  • Highly deliverable outgoing mail
  • Custom URL
  • Plugin library
  • Community portals
  • Same business day support
  • Email and phone support


$60/month per seat
(minimum of 10 seats)
All Pro features, plus:
  • Top-priority 24/7 support
  • Database cluster w/ read replicas and instant failover
  • Install your own custom plugins
  • Live chat access to developers

Is there a discount for paying annually?

Yes! We offer a 10% discount for subscriptions that are billed annually rather than monthly.

This reflects the fact that we can better forecast our costs and lock in longer term discounted rates (longer leases, reservations, bulk purchasing). We pass along the cost reduction.

Contact us to switch your subscription to annual billing and we’ll add the discount automatically.

Do you provide academic discounts?

Yes! We offer a 25% discount to qualified academic institutions. Please contact us for details.

Do you offer a discount to charities and non-profits?

Yes! Please contact us for details.

Do you provide a volume discount for Cerb Cloud subscriptions?

Yes! Volume discounts are available for subscriptions with more than 25 seats.

Pro Volume Pricing
Seats Seat/Month
1-25 $40.00
26-50 $38.50
51-75 $37.00
76-100 $35.50
101-125 $34.00
126-150 $32.50
151-175 $31.00
176-200 $29.50
201-225 $28.00
226-250 $26.50
251-275 $25.00
276-300+ $23.50
Enterprise Volume Pricing
Seats Seat/Month
1-25 $60.00
26-50 $57.75
51-75 $55.50
76-100 $53.25
101-125 $51.00
126-150 $48.75
151-175 $46.50
176-200 $44.25
201-225 $42.00
226-250 $39.75
251-275 $37.50
276-300+ $35.25

If you have multiple Cerb Cloud subscriptions on your account, the sum of all seats of the same subscription type determines your volume discount. This is particularly beneficial for large companies with many subsidiaries using independent instances of Cerb, and outsourced support companies who use distinct Cerb environments for each client to provide their services.

How many workers can I invite to a Cerb Cloud trial?

By default, your trial allows unlimited worker accounts with 3 seats. Contact us if you need to test with more seats and we can raise the limit.

Do you require a credit card to start a free trial?

No! All we require is a valid email address to contact you. You will never receive an invoice until you request one.

Do I need my own email server to use Cerb Cloud?

No, we provide a high-volume SMTP service for outgoing mail with SPF and DKIM support. We also provide a redirect mailbox for instantly delivering incoming mail.

You can easily configure Cerb to use remote mail services if desired.

With Cerb Cloud, we provide you with a subdomain worth of temporary email addresses, like * You can send and receive email from any of these addresses (e.g. billing@, support@, sales@), which makes it much practice routing work to the appropriate groups/buckets in Cerb.

We also configure SPF, DKIM, and DMARC records for these temporary email addresses so you can test our mail deliverability.

If you switch to a Cerb Cloud subscription, you can even use these email addresses in production, but you’ll probably want to use your own domains. We’ll help you configure the SPF, DKIM, and DMARC records on your domains to optimize your mail deliverability from Cerb as well.

How fast is incoming mail delivered into Cerb?

When mail is received by your redirect mailbox it will be delivered into Cerb instantly (within seconds). This enables you to respond more quickly to your customers.

If you choose to use remote mailboxes instead, new mail will generally be downloaded every few minutes.

Can I use my own URL, rather than *

Yes! We’ll always use an * domain to identify your Cerb Cloud instance internally, but you can use a DNS CNAME record to access your site with a custom domain like You can also use a custom domain for each community portal you deploy.

Keep in mind that you’ll need to provide an SSL certificate for each custom domain you use. We provide wildcard SSL certificates for * and the generic portal domains like * and *

What if I plan to eventually host Cerb myself?

We still recommend that you start with a Cerb Cloud trial, so your team can immediately get to work learning about Cerb rather than getting bogged down with installation requirements and troubleshooting.

This also allows us to provide the highest level of assistance during your evaluation. We provide temporary email accounts so you can easily test incoming and outgoing messages, we’ve already installed the prerequisites for every plugin, etc.

All of your Cerb Cloud configuration and data can be exported to a standalone instance of Cerb at any time. Once you’re confident that Cerb is a good fit for your team, we’re happy to help you with that migration.

If you still need to evaluate Cerb in your own environment, you can simply grab a copy of the project from GitHub and follow the installation instructions.

Can I install custom plugins in Cerb Cloud?

Every Cerb Cloud instance can use any of the plugins in the official Plugin Library. These plugins have been developed or audited by our development team and they are guaranteed to be safe.

Enterprise subscriptions have the ability to install custom third-party plugins. These plugins must be reviewed and approved by our development team prior to use. You’ll be asked to create a GitHub repository for the plugin if you haven’t already. If the repository is private, then you will need to grant access to the cerb account.

Why does the Enterprise subscription require at least 10 seats?

That’s the point where it becomes cost effective for us to provide the extra services.

The Enterprise subscriptions can scale up to a pool of resources that are entirely dedicated to a single instance of Cerb. The database cluster for instant failover requires at least twice the resources of a Pro subscription (and more if there are extra read replicas for scaling).

Similarly, the additional Enterprise support commitments require highly experienced developers on call around the clock.

Consider these two extremes: 1 client with 50 seats, and 50 clients with 1 seat each. Both clients result in roughly the same amount of revenue for 50 seats (the single client qualifies for a volume discount), but the 50 clients variation potentially requires 50 times the amount of resources like storage and support (negatively affecting the quality and responsiveness of our services). The enterprise option is predicated on having our full attention at all times.

FAQ: Cerb On-Premises

How do I install Cerb on my own hardware?

Read the installation instructions to get started.

How much does Cerb On-Premises cost?


$0 for 3 seats
Full functionality, with limitations:
  • Low-priority email support
  • No software updates
  • One free renewal per 12 months


$30/month per seat (billed annually)
Full functionality, plus:
  • 1 year of software updates
  • 1 year of priority support by email and phone
  • Hands-on assistance
  • Priority bug fixes and feature requests
  • 20% discount for timely renewals
  • Academic, non-profit, and volume discounts

Do you provide a renewal discount for existing licenses?

Yes! We automatically add a 20% “timely renewal” discount to your invoice for any license that has not been expired for more than 30 days.

Do you provide a volume discount for standalone Cerb licenses?

Yes! Volume discounts are available for Academic, Commercial, and Government licenses with more than 25 seats.

Academic Volume Discount
Seats Cost/Seat
1-25 $270
26-50 $260
51-75 $250
76-100 $240
101-125 $230
126-150 $219
151-175 $209
176-200 $199
201-225 $189
226-250 $179
251-275 $169
276-300+ $159
Commercial/Gov Volume Discount
Seats Cost/Seat
1-25 $360
26-50 $347
51-75 $333
76-100 $320
101-125 $306
126-150 $293
151-175 $279
176-200 $266
201-225 $252
226-250 $239
251-275 $225
276-300+ $212

If you have multiple non-expired Cerb licenses on your account, the sum of all seats of the same license type determines your volume discount. This is particularly beneficial for large companies with many subsidiaries using independent instances of Cerb, and outsourced support companies who use distinct Cerb environments for each client to provide their services.

Do you provide an academic discount?

Yes. We offer a 25% discount in support of academic institutions.

To qualify for an academic discount, institutions must be accredited by an agency recognized by the U.S. Department of Education (or their own national equivalent). All publicly funded K-12 and preschools automatically qualify.

What qualifies a charity or non-profit organization for a free license?

To receive a free Cerb license with ongoing software updates and more than 3 seats, a charity or non-profit must have a charter that seeks to improve the public good and be registered as a 501(c)(3) organization (or their own national equivalent). The organization should be primarily funded through public donations or grants, and such contributions should be tax deductible by the donors.

What qualifies an open source project for a free license?

To receive a free Cerb license with ongoing software updates and more than 3 seats, an open source project must have a website explaining the purpose of the project, 100% of source code available in a public repository like GitHub, and an on-premises option without licensing costs.

An open source license should only be used for that purpose, and not mixed with other commercial activity.

What is a starter license?

A starter license provides 3 seats at no cost. The license is valid for the latest version of Cerb at the time it is created. The right to run that version of the software will never expire.

Starter licenses don’t provide access to priority support or ongoing software updates. They are eligible for a single “get current” upgrade once per 12 month period. Aside from that, they have no feature-related limitations.

Registered charities and qualifying open source projects may be eligible for a higher seat limit and ongoing software updates at no cost.