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Reading a depth distribution instead of a depth number

Ask how deep a site is and you get one number, which is the least informative thing available. The finding is in the shape: where the mass sits, how fast it falls away, and what is left in the tail after it does.

The short answer

The crawl depth distribution is how many pages sit at each distance from your entry point, and the shape tells you more than any average. A healthy site peaks early and tapers; a long flat tail means pages are being reached through chains rather than hubs, and a spike far out is usually one bottleneck holding a whole section.

ImportantAudit check · Crawl depth

One number hides the whole finding

A maximum depth of nine tells you almost nothing. It might be one legal page in a footer nobody links to, or it might be four thousand product URLs. Those are different sites with the same statistic, and they need different work.

A histogram of pages by click depth. One page at depth zero, 14 at depth one, 180 at depth two, 940 at depth three, 1,400 at depth four, 620 at depth five, then a tail of 210, 90 and 40 pages at depths six, seven and eight. The 340 pages past depth six are marked as the finding.Depth is a distribution, and the tail is the finding01180294031,40046205210678depth340 pages past depth 6The peak is your structure. The tail is pagination, archives and filtersnobody decided to publish, and it is where the crawler stops coming back.
A healthy body and an unhealthy tail on the same site. The mass at depths three and four is the structure doing its job. The 340 pages past depth six are almost never a deliberate decision, and they are what the check is pointing at.

Read it in three parts. The peak tells you where your site actually lives, which is often one level deeper than the architecture diagram claims. The fall-off tells you whether your hubs are doing anything: a steep drop after the peak means sections are well linked, a slow decline means every level is being reached through a chain rather than through a hub. And the tail tells you what got generated rather than authored.

The single most useful question to ask of the chart is whether the tail is a class of page. If the 340 URLs past depth six are all paginated archive pages, that is one fix. If they are your documentation, that is a serious structural problem. The number is the same and the two findings have nothing in common.

What the shape should look like at your size

The expectation has to scale, and this is where generic advice does the most damage. A site cannot hold a hundred thousand pages within three clicks of its home page unless every page links to thousands of others, which no usable interface does.

The rough arithmetic is worth doing once. If each page links to around 100 others, depth one reaches 100, depth two reaches 10,000 and depth three reaches a million. That is the theoretical ceiling and reality is far below it, because links overlap heavily and most navigation links to the same places. A practical figure is that each level multiplies reach by somewhere between five and thirty.

Which gives you a way to judge your own chart rather than a rule to obey:

  • A few hundred pages should be mostly within three hops. If a two-hundred-page site has a tail at depth seven, that is not scale, it is a structural accident.
  • A few thousand should peak at three or four. A long, thin tail here usually means the only route into older content is chronological.
  • Past a hundred thousand, depths of six and seven are normal. The question stops being whether pages are deep and becomes whether the pages that earn money are.

Then compare the shape against your own priorities rather than against a benchmark. Overlay which depths hold your revenue pages. A distribution that looks poor but keeps every commercially important URL within two hops is a better site than a tidy chart where the products sit at five.

A distribution needs every page to exist

A histogram is a count at each depth, so it requires the whole set. There is no version of this finding for a single URL: one page has one depth, and a single number is the thing this check exists to argue against.

This one needs the full crawl

A distribution is a count of pages at every depth, so it needs the full set. One page has one depth, and a single number is the one thing this check is trying to talk you out of.

The instant search on this site audits a single page, so rather than show you a verdict it cannot support, this guide sends you to the place the check actually runs.

If your question is about one page rather than the site, the per-page check is the one to read, and it covers the three-click rule and why it is not quite a rule.

Why a whole-site shape rates the same as one page

It shares Important with the per-page depth check, which looks like a contradiction: one is a statistic about a population and the other is a fact about a URL. They are rated together because they describe the same mechanism at two resolutions, and neither of them excludes a page from anything.

What this version adds is scope. A per-page finding is fixed with a link. A distribution finding usually names a class of page and a cause, and the fix is a template or a hub that moves hundreds of URLs at once. That is more valuable and no more urgent, which is why the rating does not change.

It stays below Critical for the same reason depth does: deep pages are crawled, indexed and served, and the cost is staleness and reduced internal recommendation rather than exclusion. The checks that genuinely remove pages, a route that dead-ends or a block, are rated higher and are frequently the actual cause of a tail like this one.

Approximating the histogram from a sitemap

A real distribution needs a crawl. A decent approximation needs your sitemap and the observation that path segments usually track depth on a well-structured site.

depth-shape.sh
curl -s https://example.com/sitemap.xml \
  | grep -o '<loc>[^<]*</loc>' | sed 's/<[^>]*>//g' \
  | sed 's|https\?://[^/]*||' \
  | awk -F/ '{ print NF - 1 }' \
  | sort -n | uniq -c \
  | awk '{ printf "%d segments: %5d  ", $2, $1
           for (i = 0; i < $1 / 20; i++) printf "#"
           print "" }'

# and the deep end, listed, because the pattern is the finding
curl -s https://example.com/sitemap.xml \
  | grep -o '<loc>[^<]*</loc>' | sed 's/<[^>]*>//g' \
  | awk -F/ 'NF - 3 >= 5' | head -20

Path depth is not click depth, and the difference is the point: a flat URL can be deep in the graph and a nested one can be one click away. Treat the output as a way of finding candidates, then check the ones that look wrong with the per-page walk.

The second command is the more useful of the two. Read the twenty deepest paths and see whether they have something in common. They almost always do, and that commonality is the template to fix.

Questions this check raises

What does a good crawl depth distribution look like?
Most pages within two to four clicks, a clear peak, and a tail that thins out rather than staying flat. The exact shape depends on size: a fifty-page site should be almost entirely within two, while a fifty-thousand-page site with everything inside three is usually a mega menu rather than good architecture.
Why is average depth misleading?
Because it hides the tail, which is where the problem is. A site averaging 2.8 clicks can have four hundred pages at depth seven, and the average will not move enough to notice. The distribution shows them; one number does not.
What causes a spike at one depth?
Usually a single bottleneck: one paginated listing, one category index, or one filter page that every item behind it is reached through. Everything inherits that page depth plus one, so the histogram grows a spike exactly one step past it.