Free Web Performance Tools - SpeedVitals
11 sharp tools. One faster web.
Measure real-user performance, isolate bottlenecks, optimize delivery, and model the business impact without leaving the SpeedVitals workflow.
Performance workspace 11 tools
01 Measure
Core Web Vitals Checker
Read the real-world LCP, INP, and CLS experienced by Chrome users, with current and historical CrUX data.
LCP 2.1s
INP 164ms
CLS 0.08
28-day field trend
02 Measure at scale
Batch Core Web Vitals Checker
Audit up to 500 URLs together and turn site-wide field data into a clear optimization queue.
| URL | LCP | INP |
|---|---|---|
| /** | 2.2s | 178ms |
| /shop | 3.1s | 164ms |
| /blog | 2.4s | 238ms |
03 Optimize
Image Compressor
Compress, resize, and convert images locally to AVIF, WebP, JPEG XL, and other modern formats.
| Format | Size | Reduction |
|---|---|---|
| PNG | 1.84 MB | −68% |
| AVIF | 586 KB |
04 Benchmark
CDN Performance Tracker
Compare CDN response times across providers, regions, percentiles, and historical windows.
| Provider | Global p75 TTFB |
|---|---|
| Edge 01 | 178 ms |
| Edge 02 | 246 ms |
| Edge 03 | 413 ms |
05 Model impact
Web Performance ROI Calculator
Translate an LCP improvement into projected conversion lift, monthly gain, and annual net value.
Estimated net impact $14,139/ month
Conversion uplift +11.39%
06 Diagnose
HAR File Analyzer
Inspect request waterfalls, payload weight, status codes, and bottlenecks without uploading your HAR file.
0 ms8001.6 s
| File | Status |
|---|---|
| document | |
| app.js | |
| hero.avif | |
| analytics |
07 Optimize
Critical CSS Generator
Extract above-the-fold styles for the viewports that matter and reduce render-blocking CSS.
.hero { display: grid; min-height: 80vh;}
14.2 KB extracted
08 Validate
HTTP/3 Checker
Verify QUIC, Alt-Svc, ALPN, DNS, and transport support instead of trusting a single response header.
01 Browser Client hello
| Protocol | Status |
|---|---|
| UDP 443 | QUIC |
| Edge | ALPN h3 |
09 Diagnose
LCP Finder
Identify the Largest Contentful Paint element across mobile, tablet, and desktop with visual evidence.
LCP 2.1s
INP 164ms
CLS 0.08
28-day field trend
10 Diagnose
CLS Finder
Replay layout shifts frame by frame and isolate the elements causing visual instability on each viewport.
LCP 2.1s
INP 164ms
CLS 0.08
28-day field trend
11 Audit
SEO Analyzer
Audit metadata, headings, links, structured data, crawlability, and other essential on-page signals.
.hero { display: grid; min-height: 80vh;}
14.2 KB extracted
Not sure where to begin?
Start with what real users experience.
Check your Core Web Vitals first, then use the rest of the suite to explain and improve the result.