What is Coverage transparency?
Verified 5 August 2026
Search APIs are precise about what they found and silent about what they did not. An empty result set could mean the page does not exist, was never crawled, or was indexed and later removed — three very different facts that an agent will resolve badly if it has to guess.
Coverage transparency resolves it: present, removed with a typed reason and any replacement, or never admitted. As far as we know, unlob is the only web search API that offers it.
How unlob handles this: Coverage transparency
Common questions
What is Coverage transparency?
Coverage transparency is the ability to ask a search index why a specific URL is or is not present, and get a substantive answer.
How does Coverage transparency work in practice?
Coverage transparency resolves it: present, removed with a typed reason and any replacement, or never admitted. As far as we know, unlob is the only web search API that offers it.
See it working
The free tier is 10,000 requests a month with no card — enough to test any of this against your own queries.