The Best Resources (with Alexa Rank)

Screaming Frog SEO Spider

Screaming Frog SEO Spider

The Screaming Frog SEO Spider is a small desktop program (PC or Mac) which crawls websites’ links, images, CSS, script and apps from an SEO perspective.

httpstatus.io

httpstatus.io

httpstatus.io – HTTP Status Code Checker.

Browseo

Browseo

Browseo.net – Your New SEO Browser. View any web page like search engines see it. Browseo helps you to identify issues with your site and with competitors’ sites. 100% free.

Server Headers

Server Headers

ServerHeaders.com – Check Server Headers & SEO Issues.

SEO Macroscope

SEO Macroscope

SEO Macroscope – Free and open source website broken link checker and Technical SEO toolbox for Windows.

Greenflare

Greenflare

Greenflare SEO Web Crawler. Open Source SEO Crawler and Analysis Tool for Windows, macOS and Linux.