Science and measurement
NCBI E-utilities database list
The index of every database E-utilities can query — the first call anybody makes against PubMed's API, and it answers in XML.
E-utilities is one of the largest XML APIs still in daily scientific use, and it is XML-first rather than XML-as-an-afterthought: the JSON forms came later and cover less.
This particular call is tiny and stable, which makes it the right one to point at from a reference.
- Publisher
- US National Library of Medicine
- Host
eutils.ncbi.nlm.nih.gov- Format
- Not one of the formats we document
- Root when listed
- eInfoResult (2026-08-18)
- Size when listed
- 1.1 KB
Where it reaches
Also in this category
- Earthquakes, past hourEvery earthquake detected worldwide in the last hour, as Atom with georss coordinates on each entry.
- arXiv computer scienceNew computer science preprints, as an RSS feed large enough to be a real test — several megabytes of abstracts.
- NOAA tide observationsThe latest water level from a single tide station, in about two hundred bytes — the smallest useful XML document in this directory.
Get started
Bring order to the XML your team can't afford to ignore.
Create a free account and get a private workspace to search, validate, diff, and monitor your XML feeds, sitemaps, schemas, and vendor integrations.