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Developer Tools · head to head

Envoy vs Keygen

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
Keygen logo

Keygen

Cybersecurity

Open, source-available software licensing API

From
Free
Free plan
Yes
Visit KeygenFull review

The short version

  • Both are free.
  • Where Keygen falls short: specific Active Licensed User (ALU) pricing not listed; requires interactive pricing calculator.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Envoy and Keygen actually diverge.

Attributes where Envoy and Keygen differ
AttributeEnvoyKeygen
Pricing modelOpen-sourceUsage-based
CategoryDeveloper ToolsCybersecurity

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

Nothing recorded that Envoy does not also cover.

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 Keygen
  • An edge or API gateway that needs per-route retry budgets, circuit breaking and outlier detection rather than round-robin proxyingnot Keygen
  • Migrating traffic between service versions or between a monolith and its replacement, using weighted splits and shadow trafficnot Keygen
  • 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 Keygen

Keygen

  • Software licensing and distributionnot Envoy
  • Product release managementnot Envoy
  • API-based license verificationnot 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

Keygen

  • Specific Active Licensed User (ALU) pricing not listed; requires interactive pricing calculator
  • Whitelabel API add-on costs $995/year per domain

Pricing, plan by plan

Envoy

Free

No published plan breakdown. See the Envoy review.

Keygen

Free
  • DevFree
    • Up to 100 Active Licensed Users
    • 10 product releases
    • Core licensing API only
  • StdOn request
    • Scaling with licensing volume
    • Distribution API (OCI/Docker, npm, Rubygems, PyPI, Tauri)
    • Flat monthly/yearly fees
  • EnterpriseOn request
    • Audit logs
    • SAML/SSO
    • IP filtering

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 Keygen if

  • You want to start without paying.
Keygen review

Questions people ask

Is Envoy or Keygen better?
Neither clearly leads. Envoy starts at Free and Keygen at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Envoy or Keygen?
Envoy starts at Free and Keygen at Free.
Does Envoy or Keygen run on more platforms?
Both run on Web, so platform support will not decide this one for you.
Can I use Envoy for free?
Both have a free tier, so you can try either at no cost before committing.
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 Keygen is typically brought in for.
What can Envoy do that Keygen cannot?
Envoy covers xDS dynamic configuration, Protocol breadth, Filter chain architecture, Observability by default.

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.

Keygen: Does Keygen have a free tier?

Yes, the Dev tier is free and supports up to 100 Active Licensed Users with 10 product releases and core licensing API access.

Source
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.

Keygen: How is Keygen pricing calculated?

Keygen uses scalable, flat monthly or yearly fees based on your licensing volume (Active Licensed Users). No revenue share or transaction fees are charged.

Source
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.

Keygen: Does Keygen charge for additional features like SSO?

SAML/SSO is included in Enterprise tiers. Whitelabel API support costs $995/year per domain. Premium Support SLA is $995/month for Enterprise.

Source
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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