Website testing
Checkers for speed, accessibility, SEO, security headers, DNS and email setup, broken links and markup, online or run yourself.
274 results, page 1 of 10
Downdetector
A website that shows whether online services, networks and games are down, based on real-time user reports.
Google Search Console
Google's free web tool for checking how a site is indexed and performs in Google Search.
GTmetrix
An online page speed tester with waterfall charts, Core Web Vitals, scheduled monitoring and alerts.
MXToolbox
A web-based suite of DNS, MX, SPF, DMARC and blacklist lookups for diagnosing email delivery.
PageSpeed Insights
Google's free web tool that reports Core Web Vitals and Lighthouse results for any URL.
Pingdom
A hosted website monitoring service with uptime, page speed, transaction checks and real user monitoring.
Screaming Frog SEO Spider
A desktop website crawler for Windows, macOS and Linux that audits sites for technical SEO issues.
Speedtest by Ookla
An internet speed test for measuring download, upload and latency in the browser or apps.
SSL Labs Server Test
A Qualys web service that analyses the TLS/SSL configuration of a public web server.
UptimeRobot
A hosted uptime monitoring service with 50 free monitors, alerts and public status pages.
VirusTotal
Online service that checks a URL or file against many antivirus engines and URL scanners.
WebPageTest
An online website performance tester with waterfall charts, filmstrips, multiple locations and throttled connections.
intoDNS
A free web tool that checks a domain's DNS and mail server health and configuration.
Accessibility Checker
WordPress plugin that scans posts and pages for accessibility problems and reports them in the editor.
Accessibility Insights
Microsoft's open-source tools for finding and fixing accessibility problems in web pages and Windows apps.
AccessibilityChecker.org
Web accessibility scanner that audits a site against WCAG and ADA and explains how to fix issues.
Accessible Color Generator
A web tool that finds the closest accessible variation of a brand color for a chosen background.
Accessible Colors
A web checker that tests text and background contrast against WCAG and suggests the closest passing colors.
AccessMonitor
A Portuguese government web service that checks web pages against WCAG 2.1 accessibility practices.
AChecker
Online accessibility checker that tests a URL, uploaded file or pasted HTML against WCAG and Section 508.
Ahrefs Broken Link Checker
Free online tool that finds broken inbound and outbound links for any website or page.
Ahrefs Free
Free website analytics, technical site audit and SEO metrics from Ahrefs for verified websites.
Am I Responsive
A web tool that shows a site on desktop, laptop, tablet and phone mockups at once.
AMP Validator
A web tool from the AMP Project that validates AMP HTML pages against the AMP specification.
ANDI
Free bookmarklet from the US Social Security Administration for testing web pages for accessibility.
Apache JMeter
An open-source Java application for load testing and measuring the performance of web applications and servers.
ARC Toolkit
Browser extension from TPGi that finds accessibility issues on individual web pages.
Artillery
Load testing and Playwright end-to-end testing toolkit with an open-source CLI and an optional cloud dashboard.
Asqatasun
Open-source, self-hosted engine that audits web pages and whole sites for accessibility and SEO.
AudioEye Website Accessibility Checker
A free online scanner that checks a website for ADA and WCAG accessibility issues.
