A Free Sitebulb Alternative for Internal Linking (No Install)

Sitebulb is one of the most respected technical-SEO crawlers around, and for good reason — its visual crawl maps and prioritised “Hints” turn a raw crawl into something you can actually act on. But it’s a paid tool with no permanent free tier, its main product is a desktop install, and its full feature set is aimed at agencies and consultants running deep audits. If what you actually need is a clear read on your internal-link structure — which pages are orphaned, which are buried too deep, where authority pools — that can be more tool than the job requires. Here’s an honest look at a lighter, free alternative for that specific job.

What Sitebulb is great at (and what it costs)

Sitebulb crawls your site and applies 300+ checks, then explains each issue in plain language with a severity and a fix — genuinely excellent for a full technical audit and for handing findings to clients. Its crawl maps render your architecture as a visual graph so you can spot orphaned clusters, deep pages, and hub bottlenecks at a glance, and it renders JavaScript using a real Chromium engine. The trade-offs: there’s a free trial but no lasting free tier, and after it you’re on a paid plan — roughly $13.50/month for Lite (capped at 10,000 URLs), about $35/month for Pro, and around $245/month for the cloud version at the time of writing. For an agency auditing client sites weekly, that’s easily worth it. For someone who just wants to know whether their internal linking is holding pages back, it’s a subscription and a download for one answer.

The lighter alternative: a free browser-based internal-linking grader

Crawlmouse takes the narrow-but-free approach. You paste a URL and it crawls the live site in the browser — nothing to install, no trial clock, no per-seat licence, and it works on any device. It maps the internal-link graph and returns a single A–F grade plus the specific problems behind it: orphan pages, pages buried too deep, weak hubs, and thin anchor text. Like Sitebulb, it shows you the structure as a graph rather than a wall of rows — but where Sitebulb gives you the whole technical toolbox, Crawlmouse gives you the internal-linking verdict, fast and free.

One real difference worth naming: Sitebulb renders JavaScript, while Crawlmouse reads the static HTML your server returns. That’s deliberate — the static read is exactly what a non-rendering AI crawler (the bots behind ChatGPT, Claude, and Perplexity) sees, so it surfaces links that only appear after JavaScript and would be invisible to those systems. Different lens, both honest: Sitebulb shows you the fully-rendered site; Crawlmouse shows you the site a plain crawler sees.

Where a free grader stops (the honest limits)

A focused tool is focused. Crawlmouse won’t give you Sitebulb’s 300 checks, its accessibility auditing, its JavaScript rendering, or its client-ready PDF reporting — it isn’t a replacement for a full technical audit, and it doesn’t pretend to be. What it does is audit and grade internal-link structure, well and for free. If you need the whole technical picture or polished agency deliverables, Sitebulb (or a similar suite) earns its price. If internal linking is the question in front of you, the free grader answers it in about two minutes.

Which should you use?

• Reach for Sitebulb when you need deep, all-in-one technical audits, visual reports for clients, JavaScript rendering, or accessibility checks — and you’re set up for a paid, mostly-desktop tool.
• Reach for a free browser grader when you specifically want to check your internal linking, you want a plain grade and a prioritised fix list rather than a full audit, or you just want the answer now without an install or a subscription. It also pairs well with the no-install approach to Screaming Frog.

They’re really different-sized tools for different jobs. A sensible move is to start with the free grade to see whether internal linking is even your problem — and bring in a heavier crawler only if the audit says you need one.