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Testing · head to head

Insomnia vs k6

Insomnia logo

Insomnia

Testing

REST and GraphQL API client for development and testing

From
Free
Rated
-
Full reviewWebsite
k6 logo

k6

Testing

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

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Insomnia git Sync on the free tier covers up to 3 users only; 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.
  • They diverge on capability: Insomnia covers REST API Client, k6 covers JavaScript test scripts.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Insomnia and k6 actually diverge.

Attributes where Insomnia and k6 differ
AttributeInsomniak6
Pricing modelfreemiumOpen source, no licence fee
PlatformsWindows, MacOS, Linux, WebWindows, macOS, Linux, Docker, Kubernetes
Founded2010Unknown

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

  • REST API Client
  • GraphQL Support
  • gRPC Support
  • GitHub
  • GitLab
  • Slack
  • Windows support
  • MacOS support

Only in k6

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

What people use each for

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

Insomnia

  • Sending and debugging HTTP, GraphQL and gRPC requestsnot k6
  • Storing collections in Git rather than a vendor cloudnot k6
  • Mocking an API endpoint before it existsnot k6
  • Running collections in CI with the Inso CLInot k6
  • Environment management across staging and productionnot k6

k6

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

Where each one falls short

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

Insomnia

  • Git Sync on the free tier covers up to 3 users only
  • Mock servers are capped at 1,000 requests a month on free, then $10 per 25,000
  • Role-based access control requires Pro at $12 per user per month
  • SSO, SCIM and vault integrations are Enterprise only at $45 per user per month
  • Working without an account is limited to the local-only Scratch Pad

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.

Pricing, plan by plan

Insomnia

Free
  • EssentialsFree
    • unlimited Cloud/Local projects
    • up to 3 users with Git Sync
    • 1,000 mock server requests/month
  • Pro$12/user/month
    • unlimited users with Git Sync access
    • unlimited organizations
    • role-based access control
  • Enterprise$45/user/month
    • Kong Konnect integration
    • SSO (SAML/OIDC)
    • SCIM provisioning

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

Which should you pick?

Choose Insomnia if

  • You need rest api client.
  • You want to start without paying.
  • You work on Windows, MacOS, Linux, Web.
  • You also want graphql support.
Insomnia review

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

Questions people ask

Is Insomnia or k6 better?
Neither clearly leads. Insomnia starts at Free and k6 at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Insomnia or k6?
Insomnia starts at Free and k6 at Free.
Does Insomnia or k6 run on more platforms?
Insomnia runs on Windows, MacOS, Linux, Web. k6 runs on Windows, macOS, Linux, Docker, Kubernetes.
Can I use Insomnia for free?
Both have a free tier, so you can try either at no cost before committing.
What is Insomnia best used for?
Insomnia is most often used for sending and debugging http, graphql and grpc requests, storing collections in git rather than a vendor cloud, mocking an api endpoint before it exists, running collections in ci with the inso cli. Of those, sending and debugging http, graphql and grpc requests and storing collections in git rather than a vendor cloud are not what k6 is typically brought in for.
What can Insomnia do that k6 cannot?
Insomnia covers REST API Client, GraphQL Support, gRPC Support, GitHub. k6 covers JavaScript test scripts, Thresholds and checks, Protocol coverage, Browser module.

Answered from the vendors’ own pages

Insomnia: How much does Insomnia cost?

Insomnia offers a free Essentials plan. Pro plans cost $12 per user per month with annual billing offering 17% savings. Enterprise plans cost $45 per user per month with support for up to 50 users self-serve; contact sales for larger teams.

Source
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.

Insomnia: Is there a free version of Insomnia?

Yes, the Essentials plan is free and includes unlimited Cloud and Local projects, Git Sync for up to 3 users, 1,000 mock server requests per month, Inso CLI, E2EE, custom linting, plugins, and AI features.

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.

Insomnia: What mock server request limits apply to Insomnia plans?

Essentials includes 1,000 mock server requests per month. Pro includes 10,000 requests per month. Enterprise includes unlimited mock server requests. Additional mock server requests beyond plan allowances cost $10 per 25,000 requests.

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.

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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