A free Screaming Frog alternative for technical SEO audits

Screaming Frog SEO Spider is the tool most technical SEOs learn first, and for good reason. It’s mature, fast, runs everywhere and does almost anything once you know where to look. This page isn’t here to tell you otherwise. It’s here to help you decide whether a free crawler covers what you actually need, and where it doesn’t.

When is Screaming Frog the better choice?

Be honest about these before switching:

• You’re on Mac or Linux. Screaming Frog runs on Windows, macOS and Linux. Crawlens is Windows-only for now.
• You crawl very large sites. With a licence, Screaming Frog has no fixed URL limit; it’s bounded by your machine’s memory and storage. Crawlens stops at 100,000 URLs per crawl.
• You need its extra features. Spelling and grammar checks, accessibility auditing, link metrics from Ahrefs, Majestic and Moz, forms-based authentication, XML sitemap generation and site visualisations aren’t in Crawlens.
• Your team already works in it. Shared configs, training and years of habits are worth something.

Where is Crawlens different?

The paid features are free

In Screaming Frog’s free version, JavaScript rendering, Search Console, Google Analytics and PageSpeed Insights integrations, saving crawls, crawl comparison, scheduling and custom extraction are all locked to the paid licence, and crawls stop at 500 URLs. Crawlens includes all of those for free, for crawls of up to 100,000 URLs.

It’s built around the audit, not the crawl

Crawlens runs 70 checks after every crawl, rolls them into a health score, and explains each issue in plain English with a concrete fix. Search Console and GA4 data feed checks of their own, such as pages with search traffic that return errors or pages ranking just below page one, so you see which problems cost traffic, not just which exist.

Log file analysis is in the same app

Screaming Frog analyses server logs in a separate product, the Log File Analyser: free for up to 1,000 log lines, $99 a year beyond that. Crawlens imports Apache, Nginx and IIS logs directly and joins them to the crawl, so you can see which indexable pages Googlebot never visits.

AI assistants are included

Both tools now ship an MCP server so Claude and other AI assistants can work with your crawl data. Screaming Frog’s is part of the paid licence and can run crawls. Crawlens’s is free and read-only by design: assistants can summarise audits, prioritise fixes and write developer tickets, but can’t start crawls or change anything. See how to connect it.

Can you use both?

Yes, and plenty of people will. Crawlens imports Screaming Frog’s Internal → All export (CSV or Excel) and maps the columns automatically. If you have a Screaming Frog licence, Crawlens can also run a headless Screaming Frog crawl with your saved settings and import the result in one step.

That gives you Screaming Frog’s crawler with Crawlens’s audit on top: the 70 checks, Search Console and GA4 joined to every URL, crawl comparison, white-label PDF reports and the MCP server.

Which should you choose?

Choose Screaming Frog if you’re on Mac or Linux, regularly crawl more than 100,000 URLs, or rely on accessibility, spelling, link metrics or authentication features.

Choose Crawlens if you’re on Windows, your sites fit within 100,000 URLs per crawl, and you’d rather not pay for JavaScript rendering, Google integrations, log analysis and AI access.

The quickest way to decide is to run both on the same site. Crawlens is free, and you can import your last Screaming Frog crawl to compare the results side by side.