Softwr

Testing · head to head

k6 vs Kong

k6 logo

k6

Testing

Load testing tool with JavaScript tests on a Go runtime, now owned by Grafana Labs

From
Free
Rated
-
Full reviewWebsite
Kong logo

Kong

APIs

Cloud-native API gateway and service connectivity platform

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: k6 tests run on a JavaScript engine embedded in Go rather than on Node.js, so npm packages, Node built-ins and existing shared test utilities generally do not work without being bundled to plain JavaScript, and often not even then.; Kong the Plus plan includes 1M API requests a month and charges $200 a month for each additional million
  • They diverge on capability: k6 covers JavaScript test scripts, Kong covers API Gateway.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which k6 and Kong actually diverge.

Attributes where k6 and Kong differ
Attributek6Kong
Pricing modelOpen source, no licence feesubscription
PlatformsWindows, macOS, Linux, Docker, KubernetesLinux, Docker, Kubernetes
CategoryTestingAPIs
FoundedUnknown2010

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 k6

  • JavaScript test scripts
  • Thresholds and checks
  • Protocol coverage
  • Browser module
  • Executors
  • xk6 extensions
  • Metrics output
  • Kubernetes operator

Only in Kong

  • API Gateway
  • Authentication & Authorization
  • Rate Limiting
  • Kubernetes
  • Consul
  • Eureka
  • PostgreSQL
  • Linux support

What people use each for

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

k6

  • Gating a deployment pipeline on a threshold such as 95th percentile latency under a defined arrival ratenot Kong
  • Generating tens of thousands of requests per second from a small number of machines without a load generator fleetnot Kong
  • Testing gRPC and WebSocket services with the same tooling and thresholds used for HTTP endpointsnot Kong
  • Correlating a load test against existing dashboards for an organisation already running Grafana and Prometheusnot Kong

Kong

  • API gateway management and routingnot k6
  • API development and testingnot k6
  • Enterprise API security and governancenot k6

Where each one falls short

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

k6

  • Tests run on a JavaScript engine embedded in Go rather than on Node.js, so npm packages, Node built-ins and existing shared test utilities generally do not work without being bundled to plain JavaScript, and often not even then.
  • The open source binary runs on a single machine, so distributed load requires the Kubernetes operator or the cloud service, and the operator is infrastructure your team has to run and debug.
  • The AGPL-3.0 licence on the core requires legal review at any company that intends to embed k6 in a product it distributes or offers as a service, which is a slower path than a permissively licensed tool.
  • There is no result storage in the open source tool, so trend history means standing up Prometheus, InfluxDB or Grafana Cloud before load testing produces anything comparable over time.
  • Since the Grafana Labs acquisition the roadmap serves the Grafana observability stack, so a buyer choosing k6 as a standalone tool should expect the standalone experience to receive less investment than the cloud and dashboard integration.
  • Grafana Cloud billing is by virtual user hour, so a long soak test at modest concurrency costs far more than its peak load suggests, and cost planning has to be done in virtual user hours rather than in test runs.

Kong

  • The Plus plan includes 1M API requests a month and charges $200 a month for each additional million
  • Plus is capped at 10M requests a month, so growth past that forces an Enterprise contract
  • Plus limits published APIs to 20 and includes one Developer Portal, with a second at $200 a month
  • SSO and audit logging are Enterprise only
  • Enterprise pricing is custom and billed annually

Pricing, plan by plan

k6

Free
  • k6 OSSFree
    • AGPL-3.0 licence
    • Full test engine, no virtual user limits
    • Runs on one machine unless distributed yourself
  • Grafana Cloud free tierFree
    • Includes a monthly allowance of virtual user hours
    • Hosted test results and dashboards
    • Shared with the rest of the Grafana Cloud free tier
  • Grafana Cloud k6$undefined/month
    • Billed by virtual user hours consumed
    • Load generation from multiple regions
    • Retained test history and comparison

Kong

Free
  • Kong Konnect Free TrialFree
    • 30-day free trial
    • Full enterprise functionality
    • Unlimited gateways
  • Kong Konnect Plus$null/month
    • Per gateway pricing billed monthly
    • Up to 5 Serverless Gateways, 2 Hybrid, 2 Dedicated Cloud Gateways
    • 1M API requests included per month
  • Kong Insomnia EssentialsFree
    • Unlimited projects and CLI access
    • Up to 3 Git Sync users
    • 1,000 mock server requests per month
  • Kong Insomnia Pro$12/month
    • Unlimited users with Git Sync access
    • Unlimited organizations
    • RBAC

Which should you pick?

Choose k6 if

  • You need javascript test scripts.
  • You want to start without paying.
  • You work on Windows, macOS, Linux, Docker, Kubernetes.
  • You also want thresholds and checks.
k6 review

Choose Kong if

  • You need api gateway.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes.
  • You also want authentication & authorization.
Kong review

Questions people ask

Is k6 or Kong better?
Neither clearly leads. k6 starts at Free and Kong at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, k6 or Kong?
k6 starts at Free and Kong at Free.
Does k6 or Kong run on more platforms?
k6 runs on Windows, macOS, Linux, Docker, Kubernetes. Kong runs on Linux, Docker, Kubernetes.
Can I use k6 for free?
Both have a free tier, so you can try either at no cost before committing.
What is k6 best used for?
k6 is most often used for gating a deployment pipeline on a threshold such as 95th percentile latency under a defined arrival rate, generating tens of thousands of requests per second from a small number of machines without a load generator fleet, testing grpc and websocket services with the same tooling and thresholds used for http endpoints, correlating a load test against existing dashboards for an organisation already running grafana and prometheus. Of those, gating a deployment pipeline on a threshold such as 95th percentile latency under a defined arrival rate and generating tens of thousands of requests per second from a small number of machines without a load generator fleet are not what Kong is typically brought in for.
What can k6 do that Kong cannot?
k6 covers JavaScript test scripts, Thresholds and checks, Protocol coverage, Browser module. Kong covers API Gateway, Authentication & Authorization, Rate Limiting, Kubernetes.

Answered from the vendors’ own pages

k6: Can I use npm packages in a k6 test?

Usually not. Scripts run on a Go-embedded JavaScript engine with no Node.js runtime, so packages depending on Node built-ins fail and pure JavaScript libraries must be bundled first.

Kong: Does Kong offer a free trial?

Yes, Kong Konnect offers a 30-day free trial with full enterprise functionality, unlimited gateways, and no credit card required.

Source
k6: Is k6 free?

The core tool is free under AGPL-3.0 with no virtual user limits. Grafana Cloud k6 is a paid service billed by virtual user hours, with a free monthly allowance.

Kong: How much does Kong Insomnia Pro cost?

Kong Insomnia Pro is $12 per user per month with 15% savings available for annual billing.

Source
k6: Does the Grafana acquisition affect the open source tool?

The tool remains open source and maintained, but investment is directed at making it a data source for Grafana, so standalone use is supported rather than prioritised.

Kong: What are Kong Konnect Plus API request limits?

Kong Konnect Plus includes 1M API requests per month; additional requests cost $200 per 1M (maximum 10M per month).

Source
k6: Can k6 replace a browser testing tool?

No. The browser module measures page-level metrics under load, but functional browser testing belongs in Playwright or a similar tool.

Kong: What is included in Kong Insomnia Enterprise?

Kong Insomnia Enterprise is $45 per user per month with SSO, SCIM, vault integrations, unlimited mock server requests, and Konnect integration.

Source
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