Free Website Performance Test
Test your website's performance for free. Get your Core Web Vitals scores, load time analysis, and prioritised recommendations to speed up your site — powered by Google Lighthouse.
No credit card required · Free forever · Results in seconds
What Our Performance Test Measures
Every metric that affects user experience and your Google rankings — analysed in one free performance test.
Core Web Vitals
- Largest Contentful Paint (LCP)
- First Input Delay (FID)
- Cumulative Layout Shift (CLS)
- First Contentful Paint (FCP)
- Interaction to Next Paint (INP)
- Total Blocking Time (TBT)
Load Time Analysis
- Time to First Byte (TTFB)
- DOM Content Loaded time
- Full page load time
- Speed Index score
- Time to Interactive (TTI)
- Critical path analysis
Resource Optimisation
- Image compression & formats
- CSS & JavaScript minification
- Render-blocking resources
- Unused CSS/JS detection
- Code splitting opportunities
- Lazy loading implementation
Network & Caching
- Browser caching headers
- CDN usage detection
- GZIP/Brotli compression
- HTTP/2 support
- Preload & prefetch hints
- Service worker caching
Mobile Performance
- Mobile speed score
- Mobile Core Web Vitals
- Viewport configuration
- Touch target sizing
- Font display settings
- Mobile-first rendering
Performance Score
- Google Lighthouse score (0-100)
- Category breakdown
- Improvement opportunities
- Diagnostics by impact
- Passing vs. failing audits
- Prioritised fix recommendations
Run Your Performance Test in 3 Steps
We Test Your Performance
StackMap runs a full performance audit powered by Google's PageSpeed Insights API — measuring load time, Core Web Vitals, and every factor affecting your Google ranking. No setup, no code, no installs.
Lighthouse Runs Full Performance Test
Our engine uses Google Lighthouse to run a comprehensive performance test — Core Web Vitals, load time, resource analysis, caching, compression, and more.
Get Prioritised Performance Report
Receive a free report showing your exact scores, what's failing, the impact of each issue on real users, and the specific improvements that will speed up your site most.
StackMap vs. Other Performance Test Tools
| Feature | StackMap | GTmetrix | Google PageSpeed | Paid Tools ($29-$99/mo) |
|---|---|---|---|---|
| Core Web Vitals | ||||
| Full Page Load Analysis | ||||
| SEO + Security Audit | — | — | ||
| Accessibility Checks | — | — | ||
| Mobile Performance | ||||
| Prioritised Fixes | — | — | ||
| Price | $0 | Free / $13+/mo | Free | $29–$99/mo |
Website Performance Test — Questions Answered
What is a website performance test?
A website performance test measures how fast and efficiently your website loads. It analyses Core Web Vitals (LCP, FID, CLS), page load time, TTFB, and other metrics that affect both user experience and Google search rankings.
What are Core Web Vitals?
Core Web Vitals are Google's three key performance metrics: Largest Contentful Paint (LCP) measures loading speed, First Input Delay (FID) measures interactivity, and Cumulative Layout Shift (CLS) measures visual stability. They directly impact your Google rankings.
What is a good website speed?
Google recommends LCP under 2.5 seconds, FID under 100ms, and CLS under 0.1. For overall page load, under 3 seconds is considered good. StackMap shows your exact scores with colour-coded pass/fail results.
How does StackMap test website performance?
StackMap uses Google Lighthouse — the same engine Google uses — to test performance. We run the test from our servers, simulate real device conditions, and measure all Core Web Vitals plus dozens of additional performance metrics.
Why is website performance important for SEO?
Since 2021, Google uses Core Web Vitals as a direct ranking factor. Slow sites rank lower than fast ones with equivalent content. Improving your performance score can directly improve your search rankings and organic traffic.
What slows down a website?
Common causes include unoptimised images, render-blocking JavaScript and CSS, no browser caching, no CDN, too many third-party scripts, large page sizes, and slow server response times. Your StackMap report identifies exactly which issues affect your site.
How do I improve my website performance score?
Your StackMap performance report prioritises opportunities by potential impact. Common wins include compressing images (use WebP format), deferring non-critical JavaScript, enabling browser caching, using a CDN, and removing unused CSS/JS.
Is StackMap's performance test free?
Yes — completely free. StackMap automatically discovers new products and sends founders a free performance report. No credit card, no trials, no limits.
Ready to test your performance? It's 100% free.
Find out your Core Web Vitals scores and exactly how to speed up your website.
Get Your Free AuditNo credit card required · Free forever · Results in seconds