Comparison

Evaluat vs k6

Both tools load-test applications. They go about it very differently. Here's where each one fits, written as fairly as we can manage.

Evaluat

Real-browser performance testing

Evaluat runs each virtual user in an isolated real browser and reports Core Web Vitals, Navigation Timing, and Apdex under load, with session video, network logs, and console logs for every user.

Open-source scriptable load testing

k6 is a modern open-source load testing tool from Grafana Labs, scripted in JavaScript and built for engineers running protocol and API load from the command line or CI. Its k6 browser module drives a real Chromium browser over the DevTools protocol and can capture browser web vitals, but it is far heavier per virtual user than a protocol request, so k6's own guidance is to use it for a share of browser-based users alongside protocol load. Grafana Cloud k6 is the hosted option.

The categorical difference: k6 is a developer-first load tester you script in JavaScript and run from the command line or CI, built for high-scale protocol and API load. It ships a browser module that drives real Chromium, but that path is resource-heavy and meant for a fraction of your users. Evaluat runs a real browser for every virtual user with no scripting, and reports Core Web Vitals, Apdex, and an Executive Summary.

At a glance

Capability comparison

Capability	Evaluat	k6
Real browser per virtual user		Browser module
No-code visual recorder
Core Web Vitals (LCP, INP, CLS, FCP) under load		Browser module
Apdex score
Executive Summary
Per-session video for every user
Full network and console logs per session
Step-by-step pass/fail playback
Hosted, no infrastructure to manage		Grafana Cloud
In-region data residency		Self-hosted
Tests as version-controlled JavaScript
High-scale protocol and API load
Open source and free

When k6 is the right call

k6 is genuinely the better tool in a few situations.

You need high-scale protocol and API load, run from code. k6 simulates protocol-level virtual users very efficiently, so a single machine drives far more HTTP and API load than any real-browser tool. For backend and API capacity testing, that is its home ground.

You want tests as version-controlled code in CI. k6 scripts are JavaScript, they live in your repository, and they run headless in any pipeline, with thresholds that fail a build. If code-as-config and a CLI-first workflow matter to your team, k6 fits.

You want open source, self-hosted or Grafana Cloud. k6 is open source under Grafana Labs and free to self-host, with Grafana Cloud k6 as the managed option and a large ecosystem of dashboards and xk6 extensions. Evaluat is a hosted commercial tool focused on the browser.

When Evaluat is the right call

Evaluat runs a real browser for every user, with no script.

You want real-browser metrics for every user, without writing a script. Evaluat runs a real browser for every virtual user and reports LCP, INP, CLS, FCP, and Apdex, recorded by clicking through your site in a visual recorder. k6's browser module needs a JavaScript test and runs a heavy Chromium instance per browser user, so teams run it for a subset of users, not all of them.

Your stakeholders need the result, not the raw numbers. Evaluat distils each run into an Executive Summary: a plain-language verdict with a health score, the key findings ranked by severity, and recommended fixes. k6 outputs metrics and threshold results you visualise in Grafana and read yourself.

You need to debug failures forensically. Evaluat keeps session video, full network logs, console output, and step-by-step pass and fail for every virtual user. k6 reports aggregate metrics and check results, with no per-session browser video.

You want a hosted tool with data residency, not scripts and load generators to maintain. Evaluat is hosted and keeps each test's data in the region the test ran in. With k6 you write and maintain the scripts and either self-host the load generators or run Grafana Cloud k6.

Common questions

FAQ

Can k6 test real browsers?

Yes, through the k6 browser module, which drives a real Chromium browser over the DevTools protocol. It is far heavier per virtual user than a protocol request, so k6's own guidance is to use it for a portion of browser-based users alongside protocol load, not for every user. Evaluat runs a real browser for every virtual user as standard, with no scripting.

Does k6 measure Core Web Vitals?

The k6 browser module can capture browser web vitals such as LCP and CLS for browser-based tests. k6's protocol virtual users measure request timings, not Core Web Vitals. Evaluat reports LCP, INP, CLS, and FCP from a real browser for every user.

Do I have to write code to use k6?

Yes. k6 tests are JavaScript, which is part of its appeal for engineers who want tests in version control. Evaluat uses a no-code visual recorder: you click through the journey once and it becomes the test.

Is k6 free?

k6 is open source and free to self-host, with Grafana Cloud k6 as the paid hosted option. Evaluat is a hosted commercial product focused on real-browser testing.

What is the Executive Summary?

After a test, Evaluat produces an Executive Summary: a plain-language verdict with a health score, the most important findings ranked by severity, and recommended fixes, grounded in the run's Core Web Vitals, Apdex, error rates, and slowest URLs. It turns a dense report into a two-minute read you can share with stakeholders.

Can Evaluat do protocol or API load like k6?

No. Evaluat tests user-facing web applications in the real browser. High-scale protocol and API load is a different layer, outside what Evaluat does.

Is Evaluat a replacement for k6?

For real-browser experience under load with no scripting, yes. For high-scale protocol and API load run from CI, k6 is the right tool, and some teams run both.

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