Performance tools for loading time, server responses and technical website quality
Free individual checks and generators · without registration
Check server responses, images, fonts, and technical loading issues. The individual checks help with the delimitation; real web vitals confirm you with browser or field data.
Just looking for the ten URL pre-checks? About the Performance Toolbox.
Server Response, HTTP and Cache
- TTFB CheckerMeasure time to first byte, redirects, HTTP version and total HTML time of a URL.
- HTTP/2/HTTP/3 checkerCheck HTTP/2 and HTTP/3 for free: distinguish negotiated protocol and alt-Svc. With clear indications about QUIC and measurement limits.
- Cache and Compression CheckerEvaluate cache control, expires, content encoding and asset caching signals.
- HTTP 304-/ETag-CheckerTest conditional HTTP requests and rank ETag, Last-Modified and real 304 responses.
Pre-examine Core-Web-Vitals Risks
- Core Web Vitals CheckerTechnical pre-checking of resource, JavaScript and layout signals. No measured LCP, INP or CLS values.
- LCP CheckerPre-check LCP risks based on server response, resources and image priority. The actual LCP is not measured.
- INP CheckerPre-check JavaScript and third parties as interaction risks. No browser interactions or measured INP values.
- CLS CheckerPre-check missing image and iframe dimensions as layout risks. Actual shifts and CLS are not measured.
- Render Blocking CheckerIdentify blocking stylesheets and synchronous scripts that brake First Paint and LCP.
Examining images and fonts
- Image Performance CheckerCheck image weight, lazy loading, image dimensions and prioritization of hero images.
- Webfont Performance CheckerCheck web font performance for free: Evaluate font families, sections, font display, source files, sizes and preloads in static HTML/CSS.
- Image compressor and WebP converterCompresses PNG, JPG and WebP locally in the browser. Set image width and quality, compare sizes and download files individually or as ZIP.
- SVG optimizerRemoves unnecessary code from static SVG graphics. Compare the original and result together with the file size and download it locally.
Optimizing JavaScript and CSS
- JavaScript Performance CheckerExternal scripts, inline blocks, known JS sizes and Async/Defer signals.
- Third Party Script CheckerMake external hosts, tracking tags, widgets and third-party scripts visible.
- CSS Minifier & FormatterMinimize or format CSS for free. Parser-assisted processing, syntax hints and receipt of license comments. Local without file upload.
- JavaScript Minifier and FormatterMinimize or format JavaScript for free. With syntax checking, module mode and obtaining variable names and license comments. Locally in the browser.
Then they join the exams.
Limiting the bottleneck
Start with the server response and a technical pre-check. A fast HTML retrieval does not mean that a page is displayed quickly or is easy to use.
TTFB CheckerInvestigate the appropriate resource
Depending on your findings, check images, fonts, blocking resources, or JavaScript. Confirm eye-catching candidates with a browser measurement before making any major changes.
Core Web Vitals CheckerMeasure again after the change
Check the delivered files and headers. Repeat browser measurements under comparable conditions and use field data as far as they are available.
Cache and Compression Checker
Frequent questions
Do the Core Web Hospitals single tools measure real LCP, INP and CLS values?
The individual checks offered provide technical preliminary checks based on HTML, resources and headers. Real Web-Vitals values must be confirmed with suitable browser measurements or field data.
How does the Performance Toolbox differ from this overview?
The Performance Toolbox bundles the ten technical URL pre-checks. This themed hub adds tools to shrink files and study fonts, HTTP versions, and cache validation.
Checking the website in connection
The free SEO check examines up to 20 URLs and bundles findings and prioritized measures.