Website testing
Checkers for speed, accessibility, SEO, security headers, DNS and email setup, broken links and markup, online or run yourself.
277 results, page 9 of 10
URLVoid
Website reputation checker that looks up a domain against more than 30 blocklist services.
UserWay Accessibility Checker
Online scanner that checks a website for ADA and WCAG accessibility issues and gives a score.
Vegeta
Command-line HTTP load testing tool that sends requests at a constant rate.
ViewDNS.info
A web collection of more than 20 DNS, IP and domain lookup tools, with a paid API.
W3C CSS Validation Service
The W3C's free service for checking CSS and style sheets in HTML documents.
W3C Feed Validation Service
A free W3C web service that checks the syntax of Atom and RSS feeds.
W3C Internationalization Checker
An online W3C tool that checks a web page's language, character encoding and internationalization settings.
W3C Link Checker
An online W3C tool that finds broken links and anchors on a web page or whole site.
W3C Markup Validation Service
The W3C's free service for checking the markup of HTML and XHTML documents.
W3Techs Site Info
A free web lookup that shows the CMS, programming language, web server and host a site uses.
wafw00f
Command-line tool that identifies and fingerprints web application firewalls in front of a site.
Watchful
A web dashboard for agencies that maintain many WordPress sites, with backups, updates and security scans.
WAVE
A suite of web accessibility evaluation tools, available online and as browser extensions.
Web Check
Open-source, self-hostable tool that analyses a website's DNS, security, headers and other public details.
WebAIM Contrast Checker
An online checker that tests foreground and background color contrast against WCAG AA and AAA levels.
Webbkoll
A web-based privacy checker for cookies, third-party requests, HTTPS and security headers.
WebGazer
A hosted service for website, API, port and cron job monitoring with public status pages.
webhint
A customizable linting tool that checks websites for accessibility, speed, compatibility and security problems.
Website Carbon Calculator
Free online tool that estimates the carbon emissions produced when a web page is loaded.
WhatCMS
A web tool that detects which CMS and other technologies power a given website.
WhatRuns
A free browser extension that shows the technologies a website is built with.
whatsmydns.net
A free online tool that checks DNS propagation against nameservers in many countries.
WhatWeb
Command-line web scanner that fingerprints the technologies running on a website.
Who.is
A web lookup for WHOIS, RDAP, DNS records, nameservers and IP ownership of any domain.
WhoCanUse
A web tool showing how a text and background color pair looks to people with various vision conditions.
Whois.com Lookup
A free web lookup for domain and IP registration details such as owner, registrar and expiry.
Whoxy
A WHOIS lookup site and pay-as-you-go API with WHOIS history and reverse WHOIS search.
Why No Padlock
Online tool that finds insecure mixed content stopping a page from showing as fully secure.
WooRank
A web-based website review that audits a URL for SEO, usability and accessibility issues.
WordPress Theme Detector
A free online tool that identifies the WordPress theme and plugins a website is using.
