# Evaluat > Evaluat is a real-browser performance testing platform that runs each virtual user in an isolated browser instance, capturing Core Web Vitals and Navigation Timing metrics under load — with full session video, network logs, and console logs for every user. ## AI and agent resources Evaluat is agent-ready: AI agents can run a real-browser website speed test over the Model Context Protocol and read the results back as structured data. - [MCP endpoint](https://www.evaluat.com/api/mcp): Model Context Protocol server (Streamable HTTP, JSON-RPC 2.0, no API key, rate limited). The tool run_website_speed_test loads a public URL once in a real browser from the UK or the EU and returns LCP and CLS, plus FCP and TTFB, Evaluat's A to F composite grade, and a shareable video report URL. A single cold load does not produce a representative INP. - [MCP server card](https://www.evaluat.com/.well-known/mcp.json): Machine-readable description of the MCP server and its tool. - [OpenAPI 3.1 specification](https://www.evaluat.com/openapi.json): The public Website Speed Test API. - [API catalog](https://www.evaluat.com/.well-known/api-catalog): RFC 9727 service catalog. - [AI plugin manifest](https://www.evaluat.com/.well-known/ai-plugin.json): Plugin manifest pointing at the OpenAPI spec. - [Developer and agent reference](https://www.evaluat.com/developers): How to connect an AI agent and call the speed test. - [Extended index](https://www.evaluat.com/llms-full.txt): The full machine-readable index. ## Product - [Performance Testing](https://www.evaluat.com/product/performance-testing): Real-browser performance testing at forecast peak traffic, sized with you, with Core Web Vitals capture per virtual user. Available through assisted private access. - [Ecommerce performance testing](https://www.evaluat.com/solutions/ecommerce-performance-testing): Peak-day revenue protection and load testing for Shopify, Magento, WooCommerce, and headless storefronts. - [Magento performance and load testing](https://www.evaluat.com/solutions/magento-performance-testing): Real-browser load testing for Magento and Adobe Commerce storefronts, catalog to checkout, including Hyvä and headless frontends. - [Checkout performance testing](https://www.evaluat.com/use-cases/checkout-performance-testing): Real-browser rehearsal of cart and payment journeys under concurrency. - [Peak readiness](https://www.evaluat.com/use-cases/peak-readiness): Black Friday, flash sale, and launch traffic rehearsals before the event. - [Testing Suite](https://www.evaluat.com/product/testing-suite): Smoke testing with the same real-browser scenarios (planned). - [Monitoring](https://www.evaluat.com/product/monitoring): Continuous real-browser performance monitoring (planned). - [How It Works](https://www.evaluat.com/how-it-works): Architecture, methodology, and what each test produces. - [What's in a report](https://www.evaluat.com/reports/examples): Walkthrough of an Evaluat report: five detail views on every plan, plus an on-demand Executive Summary (illustrative; not a public customer-report gallery). - [Changelog](https://www.evaluat.com/changelog): Dated product, tooling, and platform updates, newest first. ## Free tools - [Website Speed Test (Evaluat Pulse)](https://www.evaluat.com/tools/website-speed-test): Free website speed test that loads a public URL once in a real browser from the UK or the EU and returns LCP and CLS, plus FCP and TTFB, Evaluat's A to F composite grade, and a video replay on a shareable report link. A single cold load does not produce a representative INP. No signup; reports are kept for 30 days. ## Comparisons - [All comparisons](https://www.evaluat.com/vs): How Evaluat lines up against other load testing tools, with capability tables and honest when-to-choose-the-other-tool sections. - [Evaluat vs k6](https://www.evaluat.com/vs/k6): Real-browser testing for every user vs k6's scriptable protocol load and its resource-heavy browser module. - [Evaluat vs AppLoader](https://www.evaluat.com/vs/apploader): Real-browser Core Web Vitals vs AppLoader's GUI and protocol load testing. - [Evaluat vs Cavisson NetStorm](https://www.evaluat.com/vs/cavisson): Real-browser performance testing vs Cavisson NetStorm's enterprise multi-protocol load. - [Evaluat vs JMeter](https://www.evaluat.com/vs/jmeter): Real-browser testing for every user vs JMeter's protocol load and small-scale WebDriver Sampler. - [Evaluat vs Loadero](https://www.evaluat.com/vs/loadero): Real-browser Core Web Vitals and an Executive Summary vs Loadero's real-browser WebRTC and load testing. - [Evaluat vs LoadForge](https://www.evaluat.com/vs/loadforge): Real-browser Core Web Vitals vs LoadForge's Locust-based cloud load testing. - [Evaluat vs Loadium](https://www.evaluat.com/vs/loadium): Real-browser performance testing vs Loadium's cloud runner for JMeter, Gatling, and Selenium. - [Evaluat vs LoadView](https://www.evaluat.com/vs/loadview): Real-browser Core Web Vitals per user vs LoadView's real-browser load from Dotcom-Monitor. - [Evaluat vs Locust](https://www.evaluat.com/vs/locust): Real-browser testing with no code vs Locust's open-source Python protocol load. - [Evaluat vs OctoPerf](https://www.evaluat.com/vs/octoperf): Real-browser Core Web Vitals vs OctoPerf's JMeter-based protocol load at scale. - [Evaluat vs Web Performance Load Tester](https://www.evaluat.com/vs/web-performance): Real-browser testing for every user vs Web Performance's self-hosted load tool. ## Blog - [Blog](https://www.evaluat.com/blog): Performance testing guides, Core Web Vitals explainers, testing-type comparisons, and ecommerce load-testing writeups. - [What is load testing?](https://www.evaluat.com/blog/what-is-load-testing): What is load testing, why it matters for conversions and uptime, how a test actually works, and how many virtual users you need. A plain guide for beginners. - [Playwright for performance testing: can a browser automation tool drive virtual users?](https://www.evaluat.com/blog/playwright-performance-testing): Can Playwright do performance testing? It drives a real browser, so each virtual user measures true experience. How far it scales, and where load tools win. - [Where does performance testing fit in an agile release cycle?](https://www.evaluat.com/blog/performance-testing-agile-release-cycle): Performance testing in agile works when you right-size each test to a stage: cheap checks every commit, a real-browser load test at the pre-release gate. - [Performance testing: the complete guide](https://www.evaluat.com/blog/performance-testing-guide): Performance testing measures how your app behaves under load, from server response time to Core Web Vitals. A guide to the types, metrics, process, and tools. - [How to improve CLS: a step-by-step optimization guide](https://www.evaluat.com/blog/how-to-improve-cls): Improve CLS by reserving space before content loads: sizing images, ads, embeds, and fonts. A step-by-step guide with code, case studies, and 2025 data. - [How to improve INP: a step-by-step optimization guide](https://www.evaluat.com/blog/how-to-improve-inp): Improve INP by fixing your slowest interaction. Break up long tasks, yield to the main thread, trim handlers, and tame hydration, with code and 2025 data. - [How to improve LCP: a step-by-step optimization guide](https://www.evaluat.com/blog/how-to-improve-lcp): Improve LCP by fixing the biggest phase first. A step-by-step guide to cutting load delay, TTFB, and render-blocking resources, with code and 2025 data. - [What is an Apdex score? Measuring user satisfaction in performance testing](https://www.evaluat.com/blog/what-is-an-apdex-score): An Apdex score turns response times into one user-satisfaction number from 0 to 1. What the formula means, how to set the T threshold, and what counts as good. - [Core Web Vitals at load, explained](https://www.evaluat.com/blog/core-web-vitals-load-testing): Core Web Vitals shift under load: LCP climbs as the server slows and INP degrades at peak. Here is why each Vital moves, and how to measure them at concurrency. - [Interaction to Next Paint (INP), explained for engineers](https://www.evaluat.com/blog/interaction-to-next-paint): Interaction to Next Paint (INP) measures page responsiveness: why it replaced First Input Delay, what drags it past 200ms, and how to test it under load. - [Core Web Vitals: why lab scores differ from real users](https://www.evaluat.com/blog/core-web-vitals-lab-vs-field): Why do Core Web Vitals lab scores differ from field data? Lighthouse runs one synthetic test; real users are a spread of devices, networks, and traffic. - [Why average response time misleads you: reading p95 and p99](https://www.evaluat.com/blog/p95-p99-response-time): Average response time hides the slow requests that lose users. Read p95 and p99, see why tail latency compounds at scale, and pick the right percentile. - [8 metrics every performance test report should include](https://www.evaluat.com/blog/performance-test-report-metrics): The 8 metrics every performance test report needs, from response time percentiles to Core Web Vitals, and the benchmark that shows whether each one is healthy. - [Largest Contentful Paint (LCP), explained for engineers](https://www.evaluat.com/blog/largest-contentful-paint): Largest Contentful Paint explained for engineers: what counts as the LCP element, the four phases LCP breaks into, and how to measure and fix it under load. - [API performance testing vs browser performance testing: which your QA strategy needs](https://www.evaluat.com/blog/api-vs-browser-performance-testing): API performance testing checks your backend. Browser performance testing checks what users feel. Here is what each misses, and which your QA strategy needs. - [Performance regression testing: making Core Web Vitals a CI/CD release gate](https://www.evaluat.com/blog/performance-regression-testing): Performance regression testing catches the slowdowns a release ships. Set Core Web Vitals budgets, wire them into CI/CD, and fail the build on a regression. - [Load testing vs stress testing vs performance testing: how the three actually differ](https://www.evaluat.com/blog/load-vs-stress-vs-performance-testing): Load, stress, and performance testing get mixed up constantly. Here is how the three actually differ, when to run each, and which one your team needs first. - [What is spike testing? Preparing for traffic surges and flash sales](https://www.evaluat.com/blog/what-is-spike-testing): Spike testing throws a sudden, extreme surge of traffic at your site to see if it survives a flash sale or viral moment. A beginner's guide for QA teams. - [Soak testing explained: catching slow degradation and memory leaks over time](https://www.evaluat.com/blog/soak-testing): Soak testing holds a steady, realistic load for hours or days to surface memory leaks and slow degradation that short tests miss. Here is how it works. - [Stress testing a website: how to find the breaking point before your users do](https://www.evaluat.com/blog/stress-testing-a-website): Stress testing pushes a website past its limit to find the breaking point on purpose. A step-by-step QA guide to ramping load, spotting failure, recovering. - [Smoke testing vs performance testing: when a quick pre-release check is enough](https://www.evaluat.com/blog/smoke-testing-vs-performance-testing): Smoke testing vs performance testing: one asks if a build is broken, the other if it holds up under load. Here is when a quick pre-release check is enough. - [Real-browser load testing, explained](https://www.evaluat.com/blog/real-browser-load-testing): How real-browser load testing differs from HTTP-script and shared-browser models, what it captures that the others cannot, and when each is the right call. - [Functional testing vs performance testing: two questions every release should answer](https://www.evaluat.com/blog/functional-testing-vs-performance-testing): Functional testing vs performance testing: one asks if your software works, the other if it holds up under load. Here is how they differ and why you need both. - [Best real-browser load testing tools in 2026](https://www.evaluat.com/blog/best-real-browser-load-testing-tools): The seven best real browser load testing tools in 2026, the protocol tools with a browser mode, verified July 2026 pricing, and how to pick the right one. - [Load testing a headless or Hyvä storefront](https://www.evaluat.com/blog/load-testing-headless-hyva-storefront): Headless and Hyvä storefronts need different test models. Measure browser rendering and Magento backend capacity without confusing their architecture. - [Why your Shopify store slows down under load](https://www.evaluat.com/blog/shopify-store-slow-under-load): Shopify's edge scales, but the theme, apps, and third-party JavaScript you add run in each shopper's browser and stall under load. Here is how to test it. - [WooCommerce performance testing: find your store's limit under load](https://www.evaluat.com/blog/woocommerce-performance-testing): WooCommerce is self-hosted, so unlike Shopify you can load test it. Why cart, checkout, and admin-ajax slow under load, and how to test a staging copy safely. - [Why Magento checkout dies first under load](https://www.evaluat.com/blog/magento-checkout-slow-under-load): Magento checkout slows and fails under load because no cache can save it. See the four bottlenecks that break it first and how to load test the full journey. ## Reference - [Pricing](https://www.evaluat.com/pricing) - [FAQ](https://www.evaluat.com/faq) - [About](https://www.evaluat.com/about) - [Ahmad Farzan, founder and author](https://www.evaluat.com/authors/ahmad-farzan): Founder of Evaluat and author of the blog, with a background building and load-testing Adobe Commerce and Magento storefronts. - [Agency Partner Program](https://www.evaluat.com/partners) - [Book a Demo](https://www.evaluat.com/demo) - [Contact](https://www.evaluat.com/contact) ## Legal - [Privacy](https://www.evaluat.com/privacy) - [Terms](https://www.evaluat.com/terms) - [Data Processing Agreement](https://www.evaluat.com/dpa) - [Sub-processors](https://www.evaluat.com/sub-processors)