arcsecond.io
Science & Math
Multiple astronomy data sources
Research datasets, astronomy, physics, chemistry and computation.
60 listed · 46 need no key · 26 work in the browser
Science & Math
Multiple astronomy data sources
Science & Math
Render LaTeX equations in PNG, GIF, SVG, EMF, PDF, JSON, or download formats with styling options
Science & Math
ISRO Space Crafts Information
Science & Math
Asterank.com Information
Science & Math
Gene annotation queries and ID lookup
Science & Math
The NASA Open APIs provide developers with easy access to a wide range of NASA data, including imagery and scientific information. These APIs are designed to enhance the usability of NASA's dataset for developers, educators, and researchers.
Science & Math
Symbolic and Arithmetic Math Calculator
Science & Math
Symbolic and Arithmetic Math Calculator
Science & Math
ISS astronauts, current location, etc
Science & Math
Open catalog of scholarly works, authors, institutions, sources, and concepts
Science & Math
3D structures of proteins and nucleic acids
Science & Math
A free, open, dataset about research and scholarly activities
Science & Math
Satellite information
Science & Math
Unit converter for standard and uncommon units
Science & Math
This API allows users to perform custom searches for earthquake information based on various parameters, such as location, time, and magnitude. It adheres to the FDSN Event Web Service Specifications, providing a structured way to access earthquake data.
Science & Math
Water quality and level info for rivers and lakes
Science & Math
Curated research-sharing platform: physics, mathematics, quantitative finance, and economics
Science & Math
Sourced, quoted specs for humanoid robots
Science & Math
Interpreted astronomy: sun and moon times, moon phases, planets, eclipses, seasons
Science & Math
Search and retrieve DOI metadata for research datasets and publications
Science & Math
Life-science literature search with abstracts, citations and full-text links
Science & Math
Global Biodiversity Information Facility
Science & Math
Global Biodiversity Information Facility
Science & Math
Access millions of museum specimens from organizations around the world
Counts and timings below come from our own scheduled checks of this category.
We track 60 in this category, of which 53 responded at our last check. 46 of them need no API key.
46 of the 60 entries here need no credential. Filter this page by "no key" to see them, or browse the no-key collection for every keyless API across all categories.
19 entries in this category need no key and return CORS headers, which is the combination that lets you call them straight from client-side JavaScript. The rest need a server or a proxy in between.
Of the keyless options that responded at our last check, ISRO was quickest at a median 347 ms. Speed is only one factor — coverage and licensing usually matter more — but it is measured here rather than claimed.
We call every listing on a schedule and record the status code, response time and whether CORS headers came back. Those results drive the badges on this page. Across the whole catalogue, 361 of 3,005 entries were not responding at the last full run, which is the sort of thing an unchecked list never tells you.