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Networking · head to head

Nebula vs OpenSearch

Nebula logo

Nebula

Networking

Certificate based overlay network from Slack, with identity and firewall rules carried in the certificate

From
Free
Rated
-
Full reviewWebsite
OpenSearch logo

OpenSearch

Databases

Open-source search and analytics suite forked from Elasticsearch

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Nebula the open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.; OpenSearch diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one
  • They diverge on capability: Nebula covers Certificate carried identity, OpenSearch covers Full-text search.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Nebula and OpenSearch actually diverge.

Attributes where Nebula and OpenSearch differ
AttributeNebulaOpenSearch
Pricing modelOpen source, no licence feeOpen source, no licence fee; managed services billed separately
PlatformsLinux, macOS, Windows, iOS, Android, FreeBSDLinux, Docker, Kubernetes, Self-hosted
CategoryNetworkingDatabases

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 Nebula

  • Certificate carried identity
  • Group based host firewall
  • Lighthouse discovery
  • Noise protocol encryption
  • Unsafe routes
  • Managed option

Only in OpenSearch

  • Full-text search
  • OpenSearch Dashboards
  • Log analytics
  • Vector search

What people use each for

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

Nebula

  • Flattening a network across several clouds and datacentres without VPC peering or route tablesnot OpenSearch
  • Very large fleets where a central policy service on the connection path is unacceptablenot OpenSearch
  • Environments that already run an internal certificate authority and want the network to use itnot OpenSearch
  • Replacing per host iptables rules with policy written against roles that follow the hostnot OpenSearch

OpenSearch

  • Log and observability storage where an Apache-2.0 licence is a requirementnot Nebula
  • Replacing Elasticsearch after the licence change without changing architecturenot Nebula
  • Search plus analytics on one cluster rather than two systemsnot Nebula

Where each one falls short

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

Nebula

  • The open source project has no user interface, no enrolment workflow and no revocation service, so certificate issuing, distribution and expiry become scripts you write and then have to keep working.
  • Revoking a compromised host means distributing a blocklist entry to every other host and reloading them, which is a fleet wide operation rather than a click, and easy to get wrong under pressure.
  • Changing a host group membership means reissuing and redeploying its certificate, so policy changes are a deployment rather than a configuration edit.
  • There is no identity provider integration or single sign on in the open source version, so it maps well to servers and badly to a fleet of user laptops.
  • NAT traversal is best effort and hosts behind symmetric NAT need a relay configured deliberately, so connectivity failures show up as intermittent rather than immediate and are awkward to diagnose.

OpenSearch

  • Diverged from Elasticsearch since 7.10, so clients, plugins and features no longer map one to one
  • Operationally heavy in the way Elasticsearch is: cluster sizing, shard strategy and JVM tuning are ongoing work
  • Smaller ecosystem of third-party tooling than Elasticsearch, which most integrations still target first
  • Overkill for plain application search, where a dedicated search engine is far simpler

Pricing, plan by plan

Nebula

Free
  • NebulaFree
    • Full functionality under the MIT licence
    • No host limit
    • You operate the certificate authority and lighthouses
  • Defined Networking$undefined/month
    • Hosted control plane and enrolment
    • Managed certificate lifecycle and revocation
    • Policy and DNS interface

OpenSearch

Free
  • OpenSearchFree
    • Full functionality
    • Self-hosted
    • No usage limits

Which should you pick?

Choose Nebula if

  • You need certificate carried identity.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, iOS, Android, FreeBSD.
  • You also want group based host firewall.
Nebula review

Choose OpenSearch if

  • You need full-text search.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Self-hosted.
  • You also want opensearch dashboards.
OpenSearch review

Questions people ask

Is Nebula or OpenSearch better?
Neither clearly leads. Nebula starts at Free and OpenSearch at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Nebula or OpenSearch?
Nebula starts at Free and OpenSearch at Free.
Does Nebula or OpenSearch run on more platforms?
Nebula runs on Linux, macOS, Windows, iOS, Android, FreeBSD. OpenSearch runs on Linux, Docker, Kubernetes, Self-hosted.
Can I use Nebula for free?
Both have a free tier, so you can try either at no cost before committing.
What is Nebula best used for?
Nebula is most often used for flattening a network across several clouds and datacentres without vpc peering or route tables, very large fleets where a central policy service on the connection path is unacceptable, environments that already run an internal certificate authority and want the network to use it, replacing per host iptables rules with policy written against roles that follow the host. Of those, flattening a network across several clouds and datacentres without vpc peering or route tables and very large fleets where a central policy service on the connection path is unacceptable are not what OpenSearch is typically brought in for.
What can Nebula do that OpenSearch cannot?
Nebula covers Certificate carried identity, Group based host firewall, Lighthouse discovery, Noise protocol encryption. OpenSearch covers Full-text search, OpenSearch Dashboards, Log analytics, Vector search.

Answered from the vendors’ own pages

Nebula: Does it use WireGuard?

No. Nebula predates the common WireGuard mesh tools and uses the Noise protocol framework with its own certificate format.

OpenSearch: Is OpenSearch free?

Yes, Apache 2.0 licensed under the Linux Foundation. Amazon OpenSearch Service is a paid managed option.

Nebula: Can I run it without Defined Networking?

Yes, entirely. Defined Networking sells the control plane conveniences, not the network itself.

OpenSearch: Why does OpenSearch exist?

Elastic moved Elasticsearch off the Apache 2.0 licence in 2021. AWS forked the last Apache-licensed version, and the project now sits under the Linux Foundation.

Nebula: How do I revoke a host?

Add its certificate fingerprint to the blocklist in the configuration of the other hosts and reload them. There is no online revocation check.

OpenSearch: Is OpenSearch compatible with Elasticsearch?

It was at the 7.10 fork point. Both have developed independently since, so compatibility weakens with every release and should be verified for the features you use.

Nebula: Is it a good fit for laptops?

Less so than the identity provider based tools. There is no single sign on, so every laptop needs a certificate issued and renewed by whatever process you build.

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