The short answer
The free tools available from search engines themselves tell you what is indexed, what is blocked and why, and how a page is actually rendered.
Most of what they find is accidental: a blocking rule left from development, a canonical pointing somewhere wrong, a page nothing links to.
What to check
| Check | Common finding |
|---|---|
| Indexed page count | Far fewer than expected |
| Pages excluded, with reasons | Blocked by an old rule |
| Rendered page | Content missing without scripts |
| Structured data validity | Errors preventing rich results |
| Mobile rendering | Content cut off or unreadable |
The excluded pages report with its stated reasons is the most useful single view. It tells you exactly why a page is not indexed rather than leaving you guessing.
Check how the page renders
- Look at the page with scripts disabled.
- Confirm the main content is present in the source.
- Confirm links are real links, not script handlers.
- Confirm headings exist and are in order.
- Compare that against what you see in your browser.
Content that only appears after scripts run can still be indexed, but it is slower and less reliable than content present in the source.
Look for the accidental blocks
- A crawl blocking rule left over from development
- A no-index instruction on a page that should be indexed
- A canonical pointing at a different page
- Pages missing from the sitemap
- Pages nothing internally links to
The first two are the most damaging and the easiest to fix. Both are usually left over from a launch and nobody checked afterwards.
Do not over-interpret the numbers
Indexed page counts fluctuate and impressions vary for reasons outside your control. Look at direction over months rather than reacting to daily changes.
The exclusion reasons and the errors are the actionable part. The counts are context.