Crawld vs Surfer
Surfer optimises a page against the current SERP. Crawld audits the whole site and ships the fix.
What Surfer is built for
On-page content optimisation: scoring a draft against what currently ranks for a keyword.
The difference
Surfer is a content editor. You give it a target keyword, it analyses what is ranking, and it scores your draft against those pages as you write. That is a genuinely useful loop and it is tight: the feedback arrives while you are still writing.
Crawld starts from the other end. It crawls the site you already have, scores it against a fixed 129-check rubric rather than against whoever currently ranks, and produces a ranked list of what to change. The output is a diff you approve, not a score to write toward.
The deeper difference is what each treats as the unit of work. For Surfer it is a page. For Crawld it is a site, which is why cannibalization between your own posts is something one of them can see and the other structurally cannot.
They also answer to different search surfaces. Surfer optimises against the ranked results page. Crawld weights 16 of its 129 checks toward whether an answer engine can lift and attribute your content, which is a different question with a different answer.
Side by side
| Feature | Crawld | Surfer |
|---|---|---|
| Unit of analysis | The whole crawled site | A page against its target keyword |
| Scoring basis | A fixed 129-check rubric with published weights | What currently ranks for the query |
| Unmeasured handling | Reported as its own state, never a pass | Not applicable: different model |
| Cannibalization | Detected across your corpus | Out of scope |
| Answer-engine readiness | 16 checks, citation share per engine | Not the focus |
| Delivery | A reviewable diff behind two human gates | Guidance in the editor |
When Surfer is the better choice
If your problem is that you are writing a specific article and want to know whether it covers what the ranking pages cover, Surfer is a better tool for that job and Crawld is not competing for it. Plenty of teams should run both.
How to check for yourself
Run the free scorecard against your own site and compare it to whatever you are using now. The number worth comparing is not the score. It is the coverage next to it. A 94 at 40% coverage and a 71 at 95% coverage are not measuring the same thing, and only one of them tells you what it did not look at.