Pages & crawl depth
The actual architecture a crawler discovers, not the one in the sitemap.
When it comes to site crawls, Screaming Frog is the go-to for most SEOs, and it is not hard to see why. But there are two annoying things nobody tells you about until you hit them: you have to install it, and the free version is limited to 500 URLs — past that it is a steep £199 a year. AlphaCrawler is a free alternative that runs in your browser. No install, nothing to download, and your laptop's CPU is not tied up doing the crawling.
| AlphaCrawler | Screaming Frog | |
|---|---|---|
| Where it runs | Browser (cloud) | Desktop app you install |
| Price | Free | Free to 500 URLs, then £199/yr |
| Setup | Paste a URL | Download, install, configure |
| Uses your RAM | No — runs remotely | Yes — large crawls need a strong machine |
| Sharing a report | A URL anyone can open | Export CSV/Excel, then send the file |
| Best for | Fast audits, broken-link checks, sharing | Very large crawls, custom extraction, integrations |
Most of the questions an SEO would ask in a normal site audit don't really need a 200,000-URL crawl. They don't need custom XPath extraction either. They simply want to know which pages are returning error responses, where the broken links are, where the redirects are becoming chains, and whether titles, descriptions, canonicals and H1s are consistent across the different templates used on a site. All of those questions are answered by AlphaCrawler.
Since the crawling happens remotely, the size of the site won't be a factor. With a desktop application, your computer needs enough resources and memory to crawl and store all the data for the site, and if you're crawling a large one you can really slow your whole machine down. Screaming Frog users work around it by allocating memory to the app or putting it in database mode. With a cloud-based crawler like AlphaCrawler this isn't a problem — you can close the page while the crawler is still running and pick it up later, and it continues right where it left off.
The ease of sharing is the other advantage a browser-based crawler has. With a desktop application you have to create a file; if you want to show a finding to a developer, you have to export that file, send it, and hope they open it in the right program. With AlphaCrawler you don't even need to send a file. You end up with a report page, so you simply send a link. The developer sees the same data — the same score, the number of issues, and a page-by-page table view — with zero software required on their end.
The actual architecture a crawler discovers, not the one in the sitemap.
4xx errors and the pages pointing at them.
301s, 302s, and the extra hops that pile up after migrations.
Missing, duplicate, too-long and too-short titles, descriptions, missing H1s, canonical issues.
How the link graph supports your important pages.
Spot the patterns, not just one-off problems.
Obviously it would be disingenuous to argue that a free web app replaces Screaming Frog for everything. If you're auditing a site with hundreds of thousands of URLs, need custom regex or XPath extraction, want to connect GA and GSC data into your crawl, or want to run scheduled crawls from the command line, then Screaming Frog — or Sitebulb — is worth the purchase and the licence fee.
But this tool covers the other 80% of crawl needs: the quick audits, the pre-launch tests, the one-minute client reports, and the broken-link sweep on a company blog you'd rather not install an app for. In those situations a free crawler is far less friction, especially when anyone on the marketing or web team can open it.
There's no signup needed to run your first few crawls, and nothing to install. Prefer a focused view? Jump straight to the free website crawler, the broken link checker, or the redirect checker.
Yes. You can crawl pages without having to install any software or pay for a licence. There are higher crawl limits should you need to crawl more pages or have more simultaneous crawls, but the core crawl and report functionality will always be free.
No. AlphaCrawler works completely in your browser, which is the reason people use it as a Screaming Frog alternative: you do not need to set up any desktop software or apps.
The free version of Screaming Frog lets you crawl 500 pages, but it has to run on your machine. AlphaCrawler runs on our servers, so you can crawl larger sites without worrying about memory, and instead of exporting the results we show a report with all the audit data for every URL.
Since the crawl is executed on our servers, it is not limited by your machine memory the way a desktop crawler is. For truly massive enterprise sites, though, you may still prefer a paid desktop crawler that lets you run custom extractions.
Every time you run a crawl we create a report with its own unique link. Send that link over and whoever owns the fix sees exactly what you see — no export, no attachment, no software on their end.