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Developer Tools · head to head

Keycloak vs Mimecast

Keycloak logo

Keycloak

Developer Tools

Open-source identity and access management server.

From
Free
Free plan
Yes
Full reviewWebsite
Mimecast logo

Mimecast

Cybersecurity

Email and collaboration security

From
$4/month
Free plan
No
Full reviewWebsite

The short version

  • Only Keycloak has a free tier, so it costs nothing to try first.
  • Each has a real cost: Keycloak requires self-hosted deployment and operational expertise to install, configure and maintain; Mimecast no pricing is published for any product or plan, and every route ends at a quote or demo request
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Keycloak and Mimecast actually diverge.

Attributes where Keycloak and Mimecast differ
AttributeKeycloakMimecast
Starting priceFree$4/month
Pricing modelopen-sourcesubscription
Free tierYesNo
PlatformsSelf-hosted, Docker, Kubernetes, Linux, Windows, APIEmail, Cloud, Collaboration
CategoryDeveloper ToolsCybersecurity
FoundedUnknown2003

Identical on both: user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Keycloak

Nothing recorded that Mimecast does not also cover.

Only in Mimecast

  • Advanced threat detection
  • Secure sharing
  • Email encryption
  • Message tracking
  • Email archiving
  • Legal hold
  • eDiscovery
  • Backup and recovery

What people use each for

The jobs each tool is most often brought in to do.

Keycloak

  • Organisations requiring self-hosted identity infrastructure for compliance or data residencynot Mimecast
  • Companies with existing LDAP/Active Directory systems needing federated authenticationnot Mimecast
  • Open-source projects and communities requiring free IAM without licensing costsnot Mimecast
  • Enterprises building custom identity workflows requiring fine-grained authorisationnot Mimecast
  • Teams with sufficient operational expertise to manage infrastructurenot Mimecast

Mimecast

  • Email security filtering against phishing and targeted attacksnot Keycloak
  • Email archiving, continuity and compliance for organisationsnot Keycloak

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Keycloak

  • Requires self-hosted deployment and operational expertise to install, configure and maintain
  • No managed cloud option provided by Red Hat; organisations must operate infrastructure themselves or use third-party distributions
  • Clustering and high-availability configurations require additional operational knowledge
  • Community support only; commercial support requires third-party vendors or distributions

Mimecast

  • No pricing is published for any product or plan, and every route ends at a quote or demo request
  • The platform is split into separately sold products for email security, awareness training, data protection and governance
  • Collaboration threat protection, DMARC analysis, incident response and email archiving are all further add ons on top of those

Pricing, plan by plan

Keycloak

Free
  • Open-sourceFree
    • Full platform functionality
    • Self-hosted deployment
    • Community support

Mimecast

$4/month
  • Defender$4/month
    • Per user
    • Threat protection
    • Impersonation prevention
  • Archive$3/month
    • Email archiving
    • Legal hold
    • Search & recall
  • Unified$6/month
    • All Defender features
    • All Archive features
    • Backup

Which should you pick?

Choose Keycloak if

  • You want to start without paying.
  • You work on Self-hosted, Docker, Kubernetes, Linux, Windows, API.
Keycloak review

Choose Mimecast if

  • You need advanced threat detection.
  • You work on Email, Cloud, Collaboration.
  • You also want secure sharing.
Mimecast review

Questions people ask

Is Keycloak or Mimecast better?
Neither clearly leads. Keycloak starts at Free and Mimecast at $4/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Keycloak or Mimecast?
Keycloak has a free tier; the other does not. Paid plans start at Free for Keycloak and $4/month for Mimecast.
Does Keycloak or Mimecast run on more platforms?
Keycloak runs on Self-hosted, Docker, Kubernetes, Linux, Windows, API. Mimecast runs on Email, Cloud, Collaboration.
Can I use Keycloak for free?
Yes. Keycloak has a free tier, so you can try it without paying. Mimecast starts at $4/month.
What is Keycloak best used for?
Keycloak is most often used for organisations requiring self-hosted identity infrastructure for compliance or data residency, companies with existing ldap/active directory systems needing federated authentication, open-source projects and communities requiring free iam without licensing costs, enterprises building custom identity workflows requiring fine-grained authorisation. Of those, organisations requiring self-hosted identity infrastructure for compliance or data residency and companies with existing ldap/active directory systems needing federated authentication are not what Mimecast is typically brought in for.
What can Keycloak do that Mimecast cannot?
Mimecast covers Advanced threat detection, Secure sharing, Email encryption, Message tracking.

Answered from the vendors’ own pages

Keycloak: What protocols does Keycloak support?

Keycloak supports OpenID Connect, OAuth 2.0 and SAML 2.0 protocols for authentication and authorisation.

Source
Mimecast: How much does Mimecast cost?

Mimecast does not publish pricing on its website. Customers must request a custom quote by contacting the sales team at +1 617 393 7000 or using the Get a Quote button.

Source
Keycloak: Can Keycloak integrate with existing user directories?

Yes. Keycloak supports user federation with LDAP and Active Directory systems, allowing organisations to leverage existing user directories.

Source
Mimecast: Is there a free trial of Mimecast?

Mimecast's trial and pricing options are not specified on the public website. Contact sales at +1 617 393 7000 or through their support portal at mimecastsupport.zendesk.com for trial availability.

Source
Keycloak: Is Keycloak free?

Yes. Keycloak is fully open-source and free to deploy and use. No licensing fees are required.

Source
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