Softwr

Testing · head to head

k6 vs Refact

k6 logo

k6

Testing

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

From
Free
Rated
-
Full reviewWebsite
Refact logo

Refact

Developer Tools

Autonomous AI coding agent for development tasks

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.; Refact requires configuration for optimal performance
  • They diverge on capability: k6 covers JavaScript test scripts, Refact covers Autonomous agent workflows.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which k6 and Refact actually diverge.

Attributes where k6 and Refact differ
Attributek6Refact
Pricing modelOpen source, no licence feeFreemium with paid tiers
PlatformsWindows, macOS, Linux, Docker, KubernetesVS Code, Web
CategoryTestingDeveloper Tools
FoundedUnknown2023

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 Refact

  • Autonomous agent workflows
  • IDE chat
  • Real-time code completions
  • GitHub integration
  • Database integration
  • On-premise deployment
  • Multi-LLM support
  • 25+ language 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 Refact
  • Generating tens of thousands of requests per second from a small number of machines without a load generator fleetnot Refact
  • Testing gRPC and WebSocket services with the same tooling and thresholds used for HTTP endpointsnot Refact
  • Correlating a load test against existing dashboards for an organisation already running Grafana and Prometheusnot Refact

Refact

  • Autonomous code generation for development tasksnot k6
  • End-to-end bug fixes and refactoringnot k6
  • Multi-language software development accelerationnot k6
  • Enterprise development with data privacy requirementsnot 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.

Refact

  • Requires configuration for optimal performance
  • On-premise deployment adds operational complexity
  • Free tier limited by daily agent request quota
  • Coin system adds complexity to cost calculation

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

Refact

Free
  • FreeFree
    • Limited daily agent usage
    • Unlimited completions
    • 2,000 coins for agent and chat
  • Pro$10/month
    • 40 daily agent requests
    • 64k context window
    • 10,000 coins monthly
  • Enterprise$undefined/custom
    • On-premise deployment
    • Custom coin allocation
    • Fine-tuning support

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 Refact if

  • You need autonomous agent workflows.
  • You want to start without paying.
  • You work on VS Code, Web.
  • You also want ide chat.
Refact review

Questions people ask

Is k6 or Refact better?
Neither clearly leads. k6 starts at Free and Refact at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, k6 or Refact?
k6 starts at Free and Refact at Free.
Does k6 or Refact run on more platforms?
k6 runs on Windows, macOS, Linux, Docker, Kubernetes. Refact runs on VS Code, Web.
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 Refact is typically brought in for.
What can k6 do that Refact cannot?
k6 covers JavaScript test scripts, Thresholds and checks, Protocol coverage, Browser module. Refact covers Autonomous agent workflows, IDE chat, Real-time code completions, GitHub integration.

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.

Refact: How many programming languages does Refact support?

Refact supports 25+ programming languages including Python, JavaScript, Go, Rust, Java, C++, and many others.

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.

Refact: Can I deploy Refact on-premises?

Yes. Refact offers on-premise deployment options for organizations requiring complete data control and privacy.

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.

Refact: What LLMs does Refact support?

Refact works with multiple LLMs including Claude, GPT-4, and open-source models, giving you flexibility in model selection.

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.

Share

Related pages

More on k6

More on Refact

Keep looking

Other head to heads