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Cybersecurity · head to head

Diligent vs Istio

Diligent logo

Diligent

Cybersecurity

Board management and enterprise GRC platform assembled from Galvanize, Steele and Diligent Boards

From
On request
Free plan
No
Visit DiligentFull review
Istio logo

Istio

Developer Tools

A Kubernetes service mesh that adds mutual TLS, traffic control and telemetry between services without changing application code.

From
Free
Free plan
Yes
Visit IstioFull review

The short version

  • Istio is free; Diligent prices on request.
  • Only Diligent lists Diligent Boards; only Istio lists automatic mutual TLS.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Diligent and Istio actually diverge.

Attributes where Diligent and Istio differ
AttributeDiligentIstio
Starting priceOn requestFree
Pricing modelQuoteOpen-source
Free tierNoYes
PlatformsWeb, iOS, Android, WindowsWeb
CategoryCybersecurityDeveloper Tools

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 Diligent

  • Diligent Boards
  • Entity management
  • Audit and analytics
  • Risk management
  • Third-party risk
  • Ethics and compliance
  • ESG and sustainability
  • Market intelligence

Only in Istio

  • Automatic mutual TLS
  • Traffic splitting
  • Resilience policies
  • Authorization policies
  • Uniform telemetry
  • Ambient mode
  • Gateway API support
  • Multi-cluster mesh

What people use each for

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

Diligent

  • A listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance systemnot Istio
  • An internal audit function moving from sampling to full-population transaction testing using the ACL heritage analytics enginenot Istio
  • A regulated firm consolidating a whistleblower hotline, third-party due diligence and policy attestation after an enforcement findingnot Istio
  • A group needing sustainability disclosure data collected with the same audit trail and controls as financial reportingnot Istio

Istio

  • Proving to an auditor that all internal service traffic is encrypted and authenticated, as a platform property rather than a per-team promisenot Diligent
  • Progressive delivery, where releases shift traffic by percentage or header and roll back without a redeploynot Diligent
  • A polyglot estate where implementing retries, timeouts and tracing in every language's client library has already failednot Diligent
  • Connecting several Kubernetes clusters into one addressable service namespace with shared workload identitynot Diligent

Where each one falls short

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

Diligent

  • The platform is an assembly of acquisitions, with the analytics engine from ACL, risk from Rsam, ethics and third-party diligence from Steele and the board portal from Diligent itself, so cross-module reporting and consistent user experience should be tested in a proof of concept rather than assumed
  • Pricing is unpublished and consistently at the top of the market, and organisations that need only one capability, a board portal or an audit analytics tool, generally pay less and get more from a specialist
  • Renewal leverage is weak once the board portal is embedded, because directors are the least willing user group to be migrated and that dependency is well understood by the vendor at renewal time
  • The analytics engine expects real data skills, and audit teams without an analytics-capable member typically use a fraction of what they licensed while paying for all of it
  • Module-by-module implementation means the promised single view of governance and risk usually arrives years after the first purchase, if the later modules are ever funded

Istio

  • Sidecar mode adds an Envoy container to every pod, which costs CPU and memory per workload and adds a hop of latency in each direction, and it introduces a startup ordering problem where an application container can begin making calls before its proxy is ready
  • Upgrades are projects rather than patches: you run revisioned control planes, canary the new revision and restart every workload to pick up new sidecars, and Istio supports only a narrow band of recent minor versions, so this recurs roughly quarterly for as long as you run it
  • The API surface is large, spanning VirtualService, DestinationRule, Gateway, PeerAuthentication, AuthorizationPolicy, Sidecar and the Kubernetes Gateway API, and a mistake usually appears as a 503 with an Envoy response flag rather than a rejected configuration, so debugging requires Envoy knowledge, not just Istio knowledge
  • Ambient mode removes the sidecar but is a different architecture with its own components and does not cover every feature the sidecar path does, so adopting it is a migration and a re-test of your policies rather than a configuration switch
  • It is Kubernetes-first; adding virtual machine workloads to the mesh is supported but much less well-trodden, so a mixed estate of Kubernetes and VMs ends up maintaining two networking and identity models
  • Below a few dozen services, most of what teams actually want (encrypted internal traffic, retries, weighted rollouts) is available from a cloud load balancer or from Linkerd with a fraction of the components, and at that scale Istio commonly becomes the single largest source of production incidents

Pricing, plan by plan

Diligent

On request
  • Diligent One PlatformOn request
    • Quoted by module and user count
    • Board portal seats priced separately from GRC modules
    • Annual subscription, commonly multi-year

Istio

Free
  • Open SourceFree
    • self-hosted installation
    • service mesh capabilities
    • cloud native computing foundation project

Which should you pick?

Choose Diligent if

  • You need diligent boards.
  • You work on Web, iOS, Android, Windows.
  • You also want entity management.
Diligent review

Choose Istio if

  • You need automatic mutual tls.
  • You want to start without paying.
  • You also want traffic splitting.
Istio review

Questions people ask

Is Diligent or Istio better?
Neither clearly leads. Diligent starts at On request and Istio at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Diligent or Istio?
Istio has a free tier; the other does not. Paid plans start at On request for Diligent and Free for Istio.
Does Diligent or Istio run on more platforms?
Diligent runs on Web, iOS, Android, Windows. Istio runs on Web.
Can I use Istio for free?
Yes. Istio has a free tier, so you can try it without paying. Diligent starts at On request.
What is Diligent best used for?
Diligent is most often used for a listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance system, an internal audit function moving from sampling to full-population transaction testing using the acl heritage analytics engine, a regulated firm consolidating a whistleblower hotline, third-party due diligence and policy attestation after an enforcement finding, a group needing sustainability disclosure data collected with the same audit trail and controls as financial reporting. Of those, a listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance system and an internal audit function moving from sampling to full-population transaction testing using the acl heritage analytics engine are not what Istio is typically brought in for.
What can Diligent do that Istio cannot?
Diligent covers Diligent Boards, Entity management, Audit and analytics, Risk management. Istio covers Automatic mutual TLS, Traffic splitting, Resilience policies, Authorization policies.

Answered from the vendors’ own pages

Diligent: Is Diligent One the same product as Galvanize?

It contains it. Diligent bought Galvanize, the ACL and Rsam merger, for around one billion dollars in April 2021, and its audit analytics and risk modules are that heritage rebranded into Diligent One.

Istio: Do we need a service mesh at all?

Only if you have enough services, or a compliance requirement, that implementing mTLS, retries and tracing per language has become unmanageable. Below roughly a few dozen services, an ingress controller plus good client libraries usually delivers more reliability for less operational cost.

Diligent: What does Diligent cost?

Not published. It is quoted by module and user, and board portal seats are priced differently from GRC seats. Expect an annual or multi-year enterprise agreement.

Istio: Sidecar mode or ambient mode?

Ambient removes the per-pod proxy and its startup ordering problems and costs less at high pod counts, but it is a newer architecture and does not cover every sidecar feature. New deployments should evaluate ambient first; existing sidecar meshes should treat the move as a migration project.

Diligent: Can you buy just the board portal?

Yes, Diligent Boards is sold on its own and is the most common entry point. The GRC modules are separate purchases.

Istio: How does it compare with Linkerd?

Linkerd is deliberately smaller, uses its own Rust proxy rather than Envoy, and is quicker to operate; Istio has a far larger feature surface, multi-cluster and VM support, and broader vendor backing. Note that Linkerd's stable distribution builds are commercially licensed by Buoyant, whereas Istio's releases are freely available.

Diligent: Does it replace a SOC 2 automation tool?

No. Diligent is aimed at enterprise audit, risk and governance, not at automated evidence collection for security certifications.

Istio: Who supports it commercially?

Solo.io and Tetrate sell supported distributions and control planes, and Google offers Cloud Service Mesh as a managed option. The upstream project itself is CNCF-governed with community support.

Istio: Does it work outside Kubernetes?

Partly. Virtual machine workloads can be added to a mesh, but the tooling, documentation and community experience are heavily Kubernetes-centred, so a VM-majority estate is fighting the grain of the project.

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