Softwr

Networking · head to head

Eclipse Mosquitto vs Vault

Eclipse Mosquitto logo

Eclipse Mosquitto

Networking

Small, EPL-licensed MQTT broker that runs on hardware other brokers cannot

From
Free
Rated
-
Full reviewWebsite
Vault logo

Vault

Cloud

Manage Secrets and Protect Sensitive Data

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Eclipse Mosquitto there is no clustering: Mosquitto is a single process, so high availability means building your own failover and accepting session loss on switchover.; Vault vault 1.15.0 and later is licensed under the Business Source License 1.1, not an OSI open source licence, with IBM Corporation as licensor
  • They diverge on capability: Eclipse Mosquitto covers MQTT 5.0 support, Vault covers Secrets management.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Eclipse Mosquitto and Vault actually diverge.

Attributes where Eclipse Mosquitto and Vault differ
AttributeEclipse MosquittoVault
Pricing modelOpen source, no licence feeopen-source
PlatformsLinux, Windows, macOS, DockerLinux, Windows, Mac, Cloud
CategoryNetworkingCloud
FoundedUnknown2015

Identical on both: starting price (Free), free tier (Yes), 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 Eclipse Mosquitto

  • MQTT 5.0 support
  • Very small footprint
  • Bridging
  • WebSockets listener
  • Command line clients
  • Dynamic security plugin

Only in Vault

  • Secrets management
  • Encryption
  • Authentication
  • Authorization
  • Audit logging
  • API access
  • High availability
  • Replication

What people use each for

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

Eclipse Mosquitto

  • A home or building automation stack where the broker must run on the same small computer as everything elsenot Vault
  • An industrial gateway that buffers local telemetry and bridges selected topics to a cloud brokernot Vault
  • Local development and testing of MQTT clients without provisioning a cloud IoT servicenot Vault
  • An air-gapped deployment where a broker with no licence server and no phone-home behaviour is a requirementnot Vault

Vault

  • Centrally storing and rotating secrets, API keys and database credentialsnot Eclipse Mosquitto
  • Issuing short-lived dynamic credentials to applications instead of static passwordsnot Eclipse Mosquitto
  • Encryption as a service and PKI certificate issuancenot Eclipse Mosquitto

Where each one falls short

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

Eclipse Mosquitto

  • There is no clustering: Mosquitto is a single process, so high availability means building your own failover and accepting session loss on switchover.
  • Persistence is a local file rather than a replicated store, so a disk failure or an unclean shutdown can lose retained messages and queued QoS traffic.
  • Practical capacity is a few thousand concurrent clients on typical hardware, so a growing device fleet eventually forces a migration to a clustered broker.
  • The Eclipse Public Licence is weak copyleft rather than permissive, which some legal teams treat as a blocker when embedding the broker in a shipped commercial product.
  • There is no commercial support to buy from the project, so production incidents rely on community mailing lists or on paying a third party who happens to know the codebase.

Vault

  • Vault 1.15.0 and later is licensed under the Business Source License 1.1, not an OSI open source licence, with IBM Corporation as licensor
  • The Additional Use Grant forbids offering Vault to third parties on a hosted or embedded basis in a paid product that competes with IBM's paid versions of Vault
  • Each version only converts to MPL 2.0 four years after that version is published, and the Change Date is tracked per version
  • Replication, HSM support, namespaces, performance standby nodes, FIPS builds, control group authorisation, multi-factor authentication, secrets sync and lease count quotas all require a Vault Enterprise licence
  • A Vault Enterprise licence must be applied to the cluster before any Enterprise feature can be used

Pricing, plan by plan

Eclipse Mosquitto

Free
  • Eclipse MosquittoFree
    • Eclipse Public License 2.0 with Eclipse Distribution Licence
    • MQTT 5.0, 3.1.1 and 3.1
    • No client or message limits beyond your hardware

Vault

Free
  • Open SourceFree
    • Secrets management
    • Encryption as a service
    • Identity management
  • EnterpriseFree
    • Advanced features
    • Premium support
    • Dedicated updates

Which should you pick?

Choose Eclipse Mosquitto if

  • You need mqtt 5.0 support.
  • You want to start without paying.
  • You work on Linux, Windows, macOS, Docker.
  • You also want very small footprint.
Eclipse Mosquitto review

Choose Vault if

  • You need secrets management.
  • You want to start without paying.
  • You work on Linux, Windows, Mac, Cloud.
  • You also want encryption.
Vault review

Questions people ask

Is Eclipse Mosquitto or Vault better?
Neither clearly leads. Eclipse Mosquitto starts at Free and Vault at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Eclipse Mosquitto or Vault?
Eclipse Mosquitto starts at Free and Vault at Free.
Does Eclipse Mosquitto or Vault run on more platforms?
Eclipse Mosquitto runs on Linux, Windows, macOS, Docker. Vault runs on Linux, Windows, Mac, Cloud.
Can I use Eclipse Mosquitto for free?
Both have a free tier, so you can try either at no cost before committing.
What is Eclipse Mosquitto best used for?
Eclipse Mosquitto is most often used for a home or building automation stack where the broker must run on the same small computer as everything else, an industrial gateway that buffers local telemetry and bridges selected topics to a cloud broker, local development and testing of mqtt clients without provisioning a cloud iot service, an air-gapped deployment where a broker with no licence server and no phone-home behaviour is a requirement. Of those, a home or building automation stack where the broker must run on the same small computer as everything else and an industrial gateway that buffers local telemetry and bridges selected topics to a cloud broker are not what Vault is typically brought in for.
What can Eclipse Mosquitto do that Vault cannot?
Eclipse Mosquitto covers MQTT 5.0 support, Very small footprint, Bridging, WebSockets listener. Vault covers Secrets management, Encryption, Authentication, Authorization.

Answered from the vendors’ own pages

Eclipse Mosquitto: Can Mosquitto be clustered?

No. It is a single process. High availability requires an external failover arrangement you build yourself.

Vault: Is HashiCorp Vault free to use?

Yes, Vault is available as a free, open-source project. The community version includes secrets management, certificate generation and rotation, encryption services, and credential management. Vault Enterprise is a commercial offering with additional features.

Source
Eclipse Mosquitto: What licence is it?

Eclipse Public License 2.0 alongside the Eclipse Distribution License, a weak copyleft rather than a permissive licence.

Vault: What are the differences between open-source Vault and Vault Enterprise?

Open-source Vault is free and self-hosted. Vault Enterprise includes additional features and commercial support. HashiCorp also offers Vault Dedicated on the HashiCorp Cloud Platform as a fully managed cloud option.

Source
Eclipse Mosquitto: How many clients can it handle?

A few thousand concurrent connections on ordinary hardware; beyond that, use a clustered broker.

Vault: Can I try HashiCorp Cloud Platform Vault without payment?

Yes, HashiCorp offers a free trial option for HCP Vault Dedicated. New users also receive a $500 credit to use across HashiCorp Cloud Platform services.

Source
Eclipse Mosquitto: Does it support MQTT 5?

Yes, along with 3.1.1 and 3.1.

Vault: What does Vault manage and protect?

Vault provides identity-based secrets management for users, machines, services, and AI agents. It automates authentication and authorization for access to secrets, passwords, certificates, encryption keys, and other sensitive data across your infrastructure.

Source
Share

Related pages

More on Eclipse Mosquitto

More on Vault

Keep looking

Other head to heads