Awesome Open Source
Awesome Open Source

Checker Services ✅

List of links to the various checkers out there on the web for sites, domains, security etc.

Table of Contents 📖

Accessibility ♿️

URL Description 💳 Checks single HTML pages for conformance with accessibility standards to ensure the content can be accessed by everyone. Free Test sites for accessibility issues (W3C/WAI - WCAG1 and WCAG2 - and E-mag). Free Test sites for accessibility issues and offer solutions for problems found. Free and paid plans Checks pages for color accessibility. Free Gives a detailed report about markup and accessibility concerns including ARIA roles. Provides solutions for problems found. Free

Browser Testing 🌎

URL Description 💳 Test websites on many browser, platforms and devices. Free Test your website for cross browser compatibility on real browsers. Instant access to multiple desktop and mobile browsers. Paid Test apps and websites in many browsers. Can be integrated in CI workflows. Free trial, free for open source projects, paid Test apps and websites in many browsers. Can be integrated in CI workflows. Free trial, free for open source projects, paid

Cron Jobs ⚡

URL Description 💳 Painless cron job scheduler & monitoring service. Paid Online Cron Job Replacement and Monitoring Service. Free Get More Out of Your Cron Jobs. Paid Simple and Effective Cron Job Monitoring. Free


URL Description 💳 Check IPs, networks, whois, ASNs, prefixes and more. Free Extensive web interface to dig for doing online DNS / nameserver query. Free and donations welcome Enter a domain name to check if its DNS servers are configured correctly. Free Check the DNS propagation of domains. Free Domain research tool that can discover hosts related to a domain. Free Monitor, validate and verify your DNS configurations. Free and paid plans Multiple DNS tools. Free DNS Lookups & Performance Monitoring. Free DNS, IP, MX tools. Free and paid plans Reverse whois & IP lookup. Free and paid plans Test if the server supports IPv6. Free Test if the server supports IPv6. Free Multiple IP address tools. Free Big collection of useful network tools. Free Trace a zone from the root, to debug delegation and whois Free Reverse/history tools for DNS, IP, MX. Free and paid plans Easy to use DNS dig tool. Free Check the MX records of a domain. Free Check for http/2 support and find network related issues. Free Big collection of useful network tools. Free Checks DNS, WHOIS, Blacklists, and more. Free, Paid Plans View DNS, IP, MX information. Free and paid plans Global DNS propagation checker. Free

Load Testing 🔥

URL Description 💳 is a FREE load testing service that allows you to stress test your web-apps & APIs with thousands of concurrent connections. Free and paid plans Load test your website, app or API instantly with up to 1.2 million concurrent users. Get unlimited tests with a free trial. Free and paid plans

Mail Configuration ✉️

URL Description 💳 Check emails addresses and lists of email addresses for existence. Free, paid premium plans Test the existence of up to 100 email addresses. Free, paid plans Test the Spammyness of your Emails. Free The blacklist check will test a mail server IP address against over 100 DNS based email. Free, paid plans Email Authentication and Configuration Tester. Free, Paid Plans Verify if an email address and the mailbox behind it exists. Free, paid plans Another email address checker. Free, paid bulk plan Test if an email address exists. Also provides an API for developers. Free, paid API

Mail Testing ✉️

URL Description 💳 Email Inbox Tester - Check over 20+ destinations. Paid Plans Preview emails in over 25 different email clients with the inbox preview feature. Free trial, paid plans Test emails in over 70 email clients, apps and on different platforms. Free trial, paid plans Test the rendering of emails in over 70 email clients and devices. Free trial, paid plans Another provider to test the rendering on many email clients and devices. Paid plans Send and debug emails in three parts (html, plain text, Apple watch). Free

Mobile Friendliness 📱

URL Description 💳 Useful for testing PWA's does mobile friendliness etc but not exclusively mobile. Free Test how easily a visitor can use your page on a mobile device. Just enter a page URL to see how your page scores. Free

Security 🔒

URL Description 💳 Browser extension that checks multiple pages at once for web security best practices. Finds HTTPS mixed content issues, insecure password forms and more. Free and paid plans Get an overview and information of assigned TLS certificates. Free Validate and check the CSP for weaknesses and security issues. Free This service provides multiple tools to check websites for vulnerabilities. Free and paid plans Harden your server's security. Free Check if a domain is on the HSTS preload list in browsers and submit them to the list. Free Track down HTTPS mixed content issues. Free and paid plans Check if there are any signs that a website is hacked. Free MageReport checks if a Magento instance is outdated and if all security patches are installed. Free Observatory by Mozilla is a project designed to help developers, system administrators, and security professionals configure their sites safely and securely. Free Multiple useful tools for CSP, HPKP, SRI, headers and certificates. Free Scott Helme built after deploying security headers like CSP and HSTS to his own site. He wanted a quick and easy way to check if other sites were using these headers and he figured he'd turn it into a useful tool for everyone to use! Free Check the SSH configuration of servers. Free This free online service performs a deep analysis of the configuration of any SSL web server on the public Internet. Free Test the strength of the available ciphers which can be used with HTTPS or SSH. Free


URL Description 💳 Browser extension that checks multiple pages at once for SEO best practices. Finds duplicate content, broken links, unfriendly URL names and more. Free and paid plans Test your websites for everything. Check spelling, broken links, SEO, accessibility and more. Paid Nibbler is a free tool for testing websites. Enter the address of any website and Nibbler will give you a report scoring the website out of 10 for key areas, including accessibility, SEO, social media and technology. Free and paid plans Evaluate your structured data (rich snippets) markup for errors or warnings. Free SEO Audit Tool and website crawler for SEO performance improving with How-to-Fix tips. Paid

Technology Used 🖥

URL Description 💳 Find out what websites are Built With. Free and paid plans

Uptime Monitoring 📉

URL Description 💳 50 monitors, 1 min intervals, 5 public status pages free. Free and paid plans No-nonsense website monitoring and status page service. Paid 2 sites, 5 euro, uptime, certificate monitoring, mixed content scanning and more. Paid only 10 monitors, 5 min intervals, branded public reporting free. Free and paid plans 50 monitors, 5 min intervals, 2 months of logs free. Free and paid plans

URL Analysis 🌐

URL Description 💳 Find out what happens when a URL is accessed. Free

Validation 👌

URL Description 💳 Checks for proper HTML and CSS markup as well as broken links. Free Checks to see if the email address is valid. Free, Paid plans

Website Performance 🚀

URL Description 💳 Browser extension that checks multiple pages at once for performance best practices. Finds unminified resources, redirect chains, render-blocking JavaScript and more. Free and paid plans PageSpeed Insights analyzes the content of a web page, then generates suggestions to make that page faster. Free GTmetrix is a free tool that analyzes your page's speed performance. Using PageSpeed and YSlow, GTmetrix generates scores for your pages and offers actionable recommendations on how to fix them. Free and paid plans Simple page load test from 3 continents. Free See how images affect your page speed. Free Checks websites for performance issues and provides reports. Free Analyze the performance with a HAR file. Free Enter a URL to test the load time of that page, analyze it and find bottlenecks. Free and paid plans Check the performance from 30+ free and 160+ paid checkpoints. Free, paid plans Website performance test tools with many options. Free Online test to help speeding up heavy web pages. Free

Contributing ✍️

This started as a small personal project.

Although this project is small, openness and inclusivity are taken seriously. To that end a code of conduct (listed in the contributing guide) has been adopted.

Contributor Guide

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