01Measure
Core Web Vitals Checker
Read the real-world LCP, INP, and CLS experienced by Chrome users, with current and historical CrUX data.
SpeedVitals performance lab
33 sharp tools. One faster web.
Measure real-user performance, isolate bottlenecks, optimize delivery, and model the business impact without leaving the SpeedVitals workflow.
Privacy-first No installationFree to use
Performance workspace33 tools
01
MeasureField data + network evidence
MeasureDiagnoseOptimizeValidate
Web Vitals
Batch checker
Image compressor
Image converter
CDN tracker
ROI calculator
HAR analyzer
Critical CSS
HTTP/3
LCP finder
CLS finder
INP debugger
SEO analyzer
Resource hints
Early hints
AI Token counter
Brotli test
ZSTD test
Ping test
Base64
GZip encode
Brotli encode
ZSTD encode
PDF to MD
HTML to MD
Word to MD
EPUB to MD
Excel to MD
Image Base64
Redirect tracer
Schema validator
Sitemap validator
Robots.txt validator
Choose your instrument
From first signal to final fix
02Measure at scale
Batch Core Web Vitals Checker
Audit up to 500 URLs together and turn site-wide field data into a clear optimization queue.
03Optimize
Image Compressor
Compress, resize, and convert images locally to AVIF, WebP, JPEG XL, and other modern formats.
04Convert
Image Converter Suite
Convert images between modern formats (AVIF, WebP, PNG, JPG, HEIF, JXL, SVG) locally in your browser with zero server uploads.
05Benchmark
CDN Performance Tracker
Compare CDN response times across providers, regions, percentiles, and historical windows.
06Model impact
Web Performance ROI Calculator
Translate an LCP improvement into projected conversion lift, monthly gain, and annual net value.
07Diagnose
HAR File Analyzer
Inspect request waterfalls, payload weight, status codes, and bottlenecks without uploading your HAR file.
08Optimize
Critical CSS Generator
Extract above-the-fold styles for the viewports that matter and reduce render-blocking CSS.
09Validate
HTTP/3 Checker
Verify QUIC, Alt-Svc, ALPN, DNS, and transport support instead of trusting a single response header.
10Diagnose
LCP Finder
Identify the Largest Contentful Paint element across mobile, tablet, and desktop with visual evidence.
11Diagnose
CLS Finder
Replay layout shifts frame by frame and isolate the elements causing visual instability on each viewport.
12Diagnose
INP Debugger
Simulate clicks and keystrokes, measure Interaction to Next Paint, and pinpoint slow scripts with Long Animation Frames.
13Audit
SEO Analyzer
Audit metadata, headings, links, structured data, crawlability, and other essential on-page signals.
14Validate
Resource Hint Validator
Audit preload, preconnect, dns-prefetch, and prefetch tags. Detect unused preloads, font double downloads, and connection savings.
15Validate
HTTP 103 Early Hints Checker
Check if your HTTPS website sends HTTP 103 Early Hints, inspect ALPN protocol negotiation, and review TLS certificates.
16Utility
Token Counter & Tokenizer
Count tokens and visualize token boundaries for OpenAI GPT, Claude, Gemini, Grok, and Llama 3 models.
17Optimize
Brotli Compression Test
Check if your website supports Brotli compression and measure real-world bandwidth savings over Gzip.
18Optimize
ZSTD Compression Test
Check if your website supports RFC 8878 Zstandard (zstd) compression and benchmark size savings over Brotli and Gzip.
19Diagnose
Online Ping Test
Measure network latency, Round Trip Time (RTT), packet loss, and jitter to any server, domain, or IP address.
20Utility
Base64 Encoder & Decoder
Encode and decode strings, files, and URLs to and from standard or URL-safe Base64 format locally in your browser.
21Utility
GZip Encoder & Decoder
Compress and decompress text or files with Gzip directly in your browser. Inspect compressed size, compression ratios, and download .gz files.
22Utility
Brotli Encoder & Decoder
Compress and decompress data using the Brotli algorithm. Benchmark compression savings, choose quality levels, and export .br files.
23Utility
ZSTD Encoder & Decoder
Compress and decompress data with Zstandard (RFC 8878). High-throughput compression benchmarking and .zst file processing.
24Convert
PDF to Markdown Converter
Convert PDF documents to clean, LLM-ready GitHub-Flavored Markdown. Preserves tables, headings, and lists.
25Convert
HTML to Markdown Converter
Convert raw HTML markup or .html files into clean Markdown tables, lists, and formatted text in real-time.
26Convert
Word to Markdown Converter
Convert Word documents (.docx, .doc, .odt, .rtf) into clean, structured Markdown for documentation and AI.
27Convert
EPUB to Markdown Converter
Convert EPUB eBooks into clean Markdown files with chapter hierarchies, headings, and quotes preserved.
28Convert
Excel to Markdown Converter
Convert Excel spreadsheets (.xlsx, .xls, .csv, .ods) into clean GitHub-Flavored Markdown tables.
29Utility
Image to Base64 Converter
Convert images to Base64 Data URIs and decode Base64 back into image files directly in your browser. 100% private and client-side.
30Diagnose
Redirect Path Tracer
Trace HTTP redirect paths hop-by-hop. Inspect 301, 302, 307, 308 status codes, response headers, and diagnose redirect loops.
31Diagnose
Schema Markup Validator
Audit Schema.org structured data, JSON-LD, and Microdata. Verify required properties, debug syntax errors, and check Google Rich Results eligibility.
32Diagnose
XML Sitemap Validator
Audit XML Sitemap and Sitemap Index files. Validate Sitemaps.org protocol limits, detect XML syntax errors, inspect <lastmod> dates, and verify image extensions.
33Diagnose
Robots.txt Validator & Tester
Audit robots.txt against RFC 9309 standards. Test crawler permissions for Googlebot, Bingbot, and AI bots, prevent site-wide blocks, and discover declared sitemaps.
Not sure where to begin?