Free web tools

Free tools to test and debug websites, by Fili

CLS Debugger

Check and visualize the Cumulative Layout Shift of any website

More free tools

HTTP/2 Test

Check whether any website is served over HTTP/2

http2test.com

HTTP/3 Test

Check whether any website supports HTTP/3 (QUIC)

http3test.com

HTTP Caching Check

Check and debug the HTTP caching headers of any URL

httpcaching.com

HTTP Compression Check

Check gzip and brotli compression of any URL

httpcompression.com

Content-Type Check

Check the Content-Type response header of any URL

contenttype.net

Free Online Port Scanner

Scan open TCP ports on any host or IP address

portscan.com

SPF, DKIM and DMARC Checker

Check email deliverability, MX records and blacklists for any domain

scan.mx