Softwr

Testing · head to head

k6 vs Katalon

k6 logo

k6

Testing

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

From
Free
Rated
-
Full reviewWebsite
Katalon logo

Katalon

Testing

Commercial low-code test automation platform built on Appium and Selenium, priced per seat plus separate cloud session add-ons

From
On request
Rated
-
Full reviewWebsite

The short version

  • Only k6 has a free tier, so it costs nothing to try first.
  • 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.; Katalon real cost stacks three separate charges, per-seat authoring licence, the True Platform add-on for test management, and per-session cloud execution, so the advertised seat price significantly understates total spend for a team running cloud tests regularly.
  • They diverge on capability: k6 covers JavaScript test scripts, Katalon covers Low-code test recording.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which k6 and Katalon actually diverge.

Attributes where k6 and Katalon differ
Attributek6Katalon
Starting priceFreeOn request
Pricing modelOpen source, no licence feePer seat per month, plus separate per-session cloud execution charges
Free tierYesNo
PlatformsWindows, macOS, Linux, Docker, KubernetesWeb, Windows, macOS

Identical on both: user rating (Not yet rated), category (Testing).

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 Katalon

  • Low-code test recording
  • Built on Selenium and Appium
  • Object repository
  • AI-assisted test generation
  • TestCloud execution
  • TestOps management

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 Katalon
  • Generating tens of thousands of requests per second from a small number of machines without a load generator fleetnot Katalon
  • Testing gRPC and WebSocket services with the same tooling and thresholds used for HTTP endpointsnot Katalon
  • Correlating a load test against existing dashboards for an organisation already running Grafana and Prometheusnot Katalon

Katalon

  • A QA team wanting a lower-code authoring layer over Selenium and Appium for testers without deep coding backgroundsnot k6
  • An organisation wanting test management and AI-assisted test maintenance bundled with automation authoring in one commercial productnot k6
  • A team needing occasional cross-browser or device cloud sessions without maintaining its own device lab or Selenium Gridnot k6
  • An enterprise wanting a single vendor and support contract for test authoring, management and cloud execution togethernot 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.

Katalon

  • Real cost stacks three separate charges, per-seat authoring licence, the True Platform add-on for test management, and per-session cloud execution, so the advertised seat price significantly understates total spend for a team running cloud tests regularly.
  • Since it is built on Selenium and Appium underneath, a team with strong automation engineers can replicate most of the core capability for free, paying only for optional cloud execution elsewhere, making Katalon's value proposition mainly about authoring speed rather than unique capability.
  • The steep first-three-seats discount versus the fourth-seat-and-beyond price means cost per seat rises sharply as a team scales past three testers on Katalon Studio alone.
  • Low-code recorded tests can become brittle and hard to maintain at scale in the same way any record-and-playback approach does, requiring the team to still write real code for complex scenarios.
  • Enterprise pricing is quote-only, so the largest deployments lose the pricing transparency the published seat tiers otherwise offer.

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

Katalon

On request
  • Katalon Studio$84/month
    • Annual billing, first three seats at 84 US dollars a seat a month
    • Fourth seat and beyond at 150 US dollars a seat a month
    • Low-code recording, object repository, Selenium and Appium engine underneath
  • True Automation$167/month
    • Annual billing, per seat
    • Includes Studio features plus test management and AI agents
    • True Platform TestOps and TestCloud sold as a further add-on at 700 US dollars a seat a year
  • Enterprise$undefined/year
    • Custom quote for private SaaS and hybrid licensing
    • Dedicated support
    • Negotiated cloud session volume

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 Katalon if

  • You need low-code test recording.
  • You work on Web, Windows, macOS.
  • You also want built on selenium and appium.
Katalon review

Questions people ask

Is k6 or Katalon better?
Neither clearly leads. k6 starts at Free and Katalon at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, k6 or Katalon?
k6 has a free tier; the other does not. Paid plans start at Free for k6 and On request for Katalon.
Does k6 or Katalon run on more platforms?
k6 runs on Windows, macOS, Linux, Docker, Kubernetes. Katalon runs on Web, Windows, macOS.
Can I use k6 for free?
Yes. k6 has a free tier, so you can try it without paying. Katalon starts at On request.
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 Katalon is typically brought in for.
What can k6 do that Katalon cannot?
k6 covers JavaScript test scripts, Thresholds and checks, Protocol coverage, Browser module. Katalon covers Low-code test recording, Built on Selenium and Appium, Object repository, AI-assisted test generation.

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.

Katalon: Is Katalon free?

No, though a 30-day free trial with no credit card is offered; the product is commercial with per-seat licensing.

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.

Katalon: Does Katalon replace Selenium and Appium?

No, it is built on top of them; Katalon adds a low-code authoring layer, test management and cloud execution rather than a different automation engine.

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.

Katalon: Is cloud execution included in the seat price?

No, TestCloud cross-browser and mobile sessions are billed separately, at 197 US dollars a session monthly or 1,899 annually per session.

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.

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