Website testing
Checkers for speed, accessibility, SEO, security headers, DNS and email setup, broken links and markup, online or run yourself.
277 results, page 5 of 10
Hybrid Analysis
Free online sandbox that runs submitted files and URLs and reports on their behaviour.
Hyperping
A hosted service for public and private status pages with built-in uptime monitoring.
IBM Equal Access Accessibility Checker
IBM's open-source browser extension and toolkit for automated accessibility checks of web pages.
ICANN Lookup
ICANN's web tool for looking up registration data for domain names and Internet number resources.
ImmuniWeb SSL Security Test
A free online test of the SSL/TLS setup of a web or email server.
Instatus
A hosted status page service with service monitoring, alerts and team incident handling.
Integrity
A free native Mac app that crawls a website and reports broken links.
Internet.nl
A web test that checks websites, mail domains and connections for modern Internet standards support.
Is It Down Right Now
A web tool that checks whether a website is down for everyone or only for you.
JSONLint
An online JSON validator and formatter that tidies and checks pasted or fetched JSON.
KeyCDN Performance Test
A free web tool that measures DNS, connection, TLS and TTFB times for one URL from 10 locations.
KeyCDN Website Speed Test
A free full-page speed test with a waterfall breakdown, run from one of 10 global locations.
Kitterman SPF Validator
Online SPF tools that retrieve and validate a domain's SPF record or test a draft record.
LearnDMARC
An interactive web console that visualizes how SPF, DKIM and DMARC evaluate a real email.
Lighthouse CI
A set of tools that runs Lighthouse audits on every commit and tracks results over time.
LinkChecker
Open-source command-line tool that checks links in web pages or crawls whole websites for broken ones.
linkinator
A command-line broken link checker that crawls websites and local files to validate every link.
Loader.io
Cloud load testing service that simulates many concurrent connections against web apps and APIs.
Locust
An open-source load testing tool where user behaviour is defined in plain Python code.
Lookyloo
Open-source web forensics tool that captures a website and maps the redirects and resources it loads.
LT Browser
A desktop browser for building, testing and debugging responsive websites across many device viewports side by side.
M-Lab Speed Test
A browser speed test from Measurement Lab that publishes its measurement data openly.
Mail Tester
A web tool that scores how likely an email is to be marked as spam.
Maileroo Mail Tester
A free web tool that grades a test email for authentication, spam score, DNS and blacklists.
Mailpit
An email testing tool that catches outgoing messages over SMTP and shows them in a web interface.
Meta Tags
A web tool to preview, edit and generate meta tags and social cards for a webpage.
Microsoft SNDS
Microsoft portal that shows senders how Outlook.com rates mail coming from their IP addresses.
Mimecast DMARC Checker
A free web tool that fetches a domain's DMARC record and explains each tag and policy.
MobileTest.me
A web tool that previews a website inside smartphone and tablet emulator frames.
Moz Link Explorer
A web-based backlink checker showing Domain Authority, linking domains and spam score for any URL.
