Browser Testing Launched

Until now, LoadForge specialised in high-scale HTTP load tests—perfect for pushing millions of virtual users against your APIs. That’s still core, but some questions live inside the browser: Largest Contentful Paint (LCP), flaky JavaScript flows, third-party widgets, visual shifts... Today you can test those too.

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Why we built it

1. True user-level performance – surface Core Web Vitals (LCP, CLS, FID) and Lighthouse metrics that request-level tests miss.
2. End-to-end functional coverage – click buttons, fill forms, follow journeys; catch regressions before users do.
3. Production monitoring – schedule low-frequency browser checks (5–10 sessions per generator) and watch metrics drift before a deploy tanks them.
4. Unified workflow – stay inside LoadForge; no extra tools or agents needed.

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Under the hood

Each LoadForge generator now embeds Playwright to run headless Chrome. You script tests with familiar Locust syntax using the PlaywrightUser class:

from locust_plugins.users.playwright import PlaywrightUser, PageWithRetry, pw, event
from locust import task

class JourneyUser(PlaywrightUser):
    @task
    @pw
    async def journey(self, page: PageWithRetry):
        async with event(self, "Home"):
            await page.goto("/")
        async with event(self, "Checkout"):
            await page.click('button:has-text("Buy now")')

Events flow back to your LoadForge dashboard just like classic Locust requests—so graphs, percentiles, and pass/fail counts “just work”.

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Perfect-fit use cases

• Core Web Vitals regression guardrails – fail if LCP > 1.2 s or CLS > 0.1.
• Critical user-journey validation – “search → product → cart → checkout” every 15 minutes.
• Visual smoke tests – capture screenshots after deploy and detect drift.
• Accessibility scanning – inject Axe and raise an error on violations.
• Edge-network performance – throttle to 3 G to ensure first paint < 2 s.

Need inspiration? Check the six ready-made scripts in the docs.

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Know the limits

Browser sessions are heavier than raw HTTP requests. A generator that drives tens of thousands of virtual users for load tests will handle ~5–10 simultaneous Chrome sessions. Browser testing is for UX & quality, not for maximum-TPS benchmarking. Combine it with classic load tests for full coverage.

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Get started now

1. Open LoadForge and select Browser Tests from the left-hand menu.
2. Create a new run using one of the example scripts or your own Playwright script.
3. Launch and watch real Chrome sessions execute live, with metrics flowing into familiar LoadForge graphs.

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Browser testing is live on every paid plan today. Spin up a run, watch Chrome fly, and unlock the UX layer of your performance story.

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Learn more: See how browser testing fits alongside HTTP load testing, API testing, and performance monitoring in the LoadForge platform.