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Developer Tools · head to head

Envoy vs Unit21

Envoy logo

Envoy

Developer Tools

A high-performance L7 proxy written in C++ that is configured by an API rather than a config file, and is usually deployed under a control plane.

From
Free
Free plan
Yes
Visit EnvoyFull review
Unit21 logo

Unit21

Cybersecurity

No-code fraud and AML risk operations platform for fintechs and neobanks

From
On request
Free plan
No
Visit Unit21Full review

The short version

  • Envoy is free; Unit21 prices on request.
  • Only Envoy lists xDS dynamic configuration; only Unit21 lists no-code rule builder.
  • Where Unit21 falls short: pricing is quoted by volume with an annual commitment, so a fintech whose growth stalls pays for headroom it did not use.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Envoy and Unit21 actually diverge.

Attributes where Envoy and Unit21 differ
AttributeEnvoyUnit21
Starting priceFreeOn request
Pricing modelOpen-sourceQuote
Free tierYesNo
CategoryDeveloper ToolsCybersecurity

Identical on both: platforms (Web).

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 Envoy

  • xDS dynamic configuration
  • Protocol breadth
  • Filter chain architecture
  • Observability by default
  • Outlier detection
  • Traffic shaping
  • mTLS termination and origination
  • Hot restart

Only in Unit21

  • No-code rule builder
  • Case management
  • SAR filing
  • Backtesting
  • Identity and device signals
  • Data ingestion API

What people use each for

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

Envoy

  • Acting as the data plane under a service mesh or Gateway API implementation, which is how the overwhelming majority of deployments use itnot Unit21
  • An edge or API gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxyingnot Unit21
  • Migrating traffic between service versions or between a monolith and its replacement, using weighted splits and shadow trafficnot Unit21
  • Standardising observability across a polyglot estate, so that latency, error rates and tracing look the same regardless of the language a service is written innot Unit21

Unit21

  • A neobank whose sponsor bank requires a documented monitoring programme before it will keep the BIN sponsorshipnot Envoy
  • A crypto exchange needing SAR filing and case management without building an internal compliance engineering teamnot Envoy
  • A payments startup where the fraud lead needs to ship a new rule the same day a new attack pattern appearsnot Envoy
  • A lender consolidating fraud alerts from three point tools into one investigator queue with a single audit trailnot Envoy

Where each one falls short

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

Envoy

  • The configuration surface is very large and hand-written bootstrap YAML runs to hundreds of lines for routing that Nginx expresses in twenty, which is why nearly every production deployment sits under a control plane and inherits that control plane's constraints as well
  • xDS is the real API and it is not stable in the comfortable sense; the v2 API set was removed outright, resource types continue to be deprecated, and your control plane and Envoy binaries have to be upgraded roughly in step or the proxies stop accepting configuration
  • Extending it properly means writing a C++ filter and building and maintaining your own Envoy binary; the alternatives are Lua, which adds per-request overhead, and proxy-wasm, whose ABI has remained effectively experimental for years with a real performance cost
  • At sidecar density the per-proxy memory and CPU footprint is a measurable share of cluster capacity, since thousands of workloads each carry a full proxy, and this is precisely the cost that has pushed mesh projects towards node-level or ambient architectures
  • There is no single vendor selling support for Envoy itself; you get the community plus control-plane vendors such as Solo.io and Tetrate, so an Envoy-level production bug is your own engineers in a C++ codebase unless a support contract happens to cover it
  • Diagnosing why a request got a particular response involves reading config dumps, the stats endpoint and the RESPONSE_FLAGS codes in access logs rather than a readable error, which is a specific skill you must hire or spend months growing

Unit21

  • It is built for fintech scale rather than card issuer scale, so organisations reaching very high transaction volumes generally re-evaluate against heavier platforms and face a migration
  • No-code rule authoring shifts power to the risk team, which is the point, but without governance it produces rule sprawl that nobody can explain to an examiner two years later
  • Detection quality depends on the signals you feed it, so a thin integration produces thin results and the platform cannot compensate with proprietary consortium data the way larger vendors do
  • Pricing is quoted by volume with an annual commitment, so a fintech whose growth stalls pays for headroom it did not use
  • SAR filing coverage is oriented to United States FinCEN reporting, so firms filing in the United Kingdom, European Union or Asia handle those submissions outside the tool

Pricing, plan by plan

Envoy

Free

No published plan breakdown. See the Envoy review.

Unit21

On request
  • Unit21 PlatformOn request
    • Priced by monitored volume and modules, annual contract
    • Fraud, AML and case management packaged separately
    • Implementation and historical data backfill quoted with the subscription

Which should you pick?

Choose Envoy if

  • You need xds dynamic configuration.
  • You want to start without paying.
  • You also want protocol breadth.
Envoy review

Choose Unit21 if

  • You need no-code rule builder.
  • You also want case management.
Unit21 review

Questions people ask

Is Envoy or Unit21 better?
Neither clearly leads. Envoy starts at Free and Unit21 at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Envoy or Unit21?
Envoy has a free tier; the other does not. Paid plans start at Free for Envoy and On request for Unit21.
Does Envoy or Unit21 run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Envoy for free?
Yes. Envoy has a free tier, so you can try it without paying. Unit21 starts at On request.
What is Envoy best used for?
Envoy is most often used for acting as the data plane under a service mesh or gateway api implementation, which is how the overwhelming majority of deployments use it, an edge or api gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxying, migrating traffic between service versions or between a monolith and its replacement, using weighted splits and shadow traffic, standardising observability across a polyglot estate, so that latency, error rates and tracing look the same regardless of the language a service is written in. Of those, acting as the data plane under a service mesh or gateway api implementation, which is how the overwhelming majority of deployments use it and an edge or api gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxying are not what Unit21 is typically brought in for.
What can Envoy do that Unit21 cannot?
Envoy covers xDS dynamic configuration, Protocol breadth, Filter chain architecture, Observability by default. Unit21 covers No-code rule builder, Case management, SAR filing, Backtesting.

Answered from the vendors’ own pages

Envoy: Should I run Envoy on its own, or under a control plane?

Almost always under one. Directly authoring xDS or static bootstrap configuration is viable for a handful of routes and becomes unmanageable beyond that. Envoy Gateway, Istio, Contour, Gloo and Consul all exist to generate that configuration for you.

Unit21: Do we need engineers to run it?

Only for the initial data integration. After that the design intent is that risk and compliance staff author and deploy rules themselves.

Envoy: How does it compare with Nginx or HAProxy?

Envoy is dynamically configured over an API and instrumented far more heavily; Nginx and HAProxy are faster to configure and lighter for straightforward reverse proxying. If you never need to change routing without a reload, Envoy is more machinery than the problem requires.

Unit21: Does it file SARs?

Yes, it generates and electronically files suspicious activity reports to FinCEN. Non-US regimes are not covered to the same depth.

Envoy: What does it cost?

Nothing to licence; it is Apache 2.0 and there is no paid edition. The cost is engineering time and, for most organisations, a commercial control plane or cloud service that packages it.

Unit21: Can we test a rule before it goes live?

Yes. Backtesting against historical data to see projected alert volume is one of the more useful parts of the product, because alert volume is the real cost.

Envoy: Can I write extensions without C++?

You can write Lua filters or proxy-wasm modules in Rust, Go, C++ or AssemblyScript. Both carry per-request overhead compared with a native filter, and the Wasm path has been slower to stabilise than the project originally projected.

Envoy: Is it a CNCF project?

Yes, it is a graduated CNCF project licensed under Apache 2.0, which means the trademark and governance sit with the foundation rather than with Lyft or any vendor.

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