Free Science & Math APIs with no API key

51 Science & Math APIs that need no API key, account or credit card. 22 of them also allow CORS, so you can call them straight from browser JavaScript. Listed by uptime and ease of use.

1
GBIF API
Online · 115 ms
Global Biodiversity Information Facility. A free science & math API by gbif.org.
- No API key needed
- Fast: 115 ms response
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
2
Macrostrat API
Online · 694 ms
Geologic maps, rock columns and stratigraphy data.
- No API key needed
- Returns JSON at its URL
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
3
Chempirical API
Online · 533 ms
Chemical compounds with physical data, reactions and substructure search.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
4
CycleCalcs API
Online · 714 ms
Interpreted astronomy: sun and moon times, moon phases, planets, eclipses, seasons.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
5
Europe PMC API
Online · 118 ms
Life-science literature search with abstracts, citations and full-text links.
- No API key needed
- Fast: 118 ms response
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
6
iNaturalist API
Online · 1121 ms
Citizen-science wildlife observations with species identification and mapping.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
7
Launch Library 2 API
Online · 876 ms
Spaceflight launches and events database.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
8
MathJS API
Online · 934 ms
Evaluate math expressions via GET or POST as JSON.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
9
Oliver's mTOR Atlas API
Online · 739 ms
Curated mTOR research: studies by evidence type, pathway claims, open questions.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
10
OpenAlex API
Online · 864 ms
Open catalog of scholarly works, authors, institutions, sources, and concepts.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
11
Remote Calc API
Online · 661 ms
Decodes base64 encoding and parses it to return a solution to the calculation in JSON.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
12
Tallytopia API
Online · 420 ms
Calculators for finance, health, math, space and sports with step-by-step results.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
13
Unpaywall API
Online · 654 ms
Open-access status and legal full-text links for scholarly articles.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
14
ENA API
Online · 564 ms
Nucleotide sequences, genomes and raw reads archive.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
15
MyGene.info API
Online · 1048 ms
Gene annotation queries and ID lookup.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
16
NCBI E-utilities API
Online · 473 ms
Biomedical literature, sequences and gene databases.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
17O
OBIS API
Online · 834 ms
Global marine species occurrence and distribution data.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
18R
RCSB PDB API
Online · 865 ms
3D structures of proteins and nucleic acids.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
19
Solar System OpenData API
Online · 500 ms
Data and facts on solar system bodies and planets.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
20
DataCite API
Online · 1239 ms
Search and retrieve DOI metadata for research datasets and publications.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
21
Open Science Framework API
Online · 361 ms
Repository and archive for study designs, research materials, data, manuscripts, etc.
- No API key needed
- Fast: 361 ms response
- HTTPS
No authHTTPSCORS ?
22
arXiv API
Online · 445 ms
Curated research-sharing platform: physics, mathematics, quantitative finance, and economics.
- No API key needed
- HTTPS
No authHTTPSCORS ?
23
iDigBio API
Online · 673 ms
Access millions of museum specimens from organizations around the world.
- No API key needed
- HTTPS
No authHTTPSCORS ?
24
inspirehep.net API
Online · 691 ms
High Energy Physics info. system.
- No API key needed
- HTTPS
No authHTTPSCORS ?
25
isEven (humor) API
Online · 804 ms
Check if a number is even.
- No API key needed
- HTTPS
No authHTTPSCORS ?
26
Purple Air API
Online · 890 ms
Real Time Air Quality Monitoring.
- No API key needed
- HTTPS
No authHTTPSCORS ?
27
arcsecond.io API
Online · 717 ms
Multiple astronomy data sources. A free science & math API by arcsecond.io.
- No API key needed
- HTTPS
No authHTTPSCORS ?
28
SatNOGS API
Online · 518 ms
Satellite observations from open ground stations.
- No API key needed
- HTTPS
No authHTTPSCORS ?
29
SHARE API
Online · 764 ms
A free, open, dataset about research and scholarly activities.
- No API key needed
- HTTPS
No authHTTPSNo CORS
30
SpaceX API
Online · 522 ms
Company, vehicle, launchpad and launch data.
- No API key needed
- HTTPS
No authHTTPSNo CORS
31
Sunrise and Sunset API
Online · 1065 ms
Sunset and sunrise times for a given latitude and longitude.
- No API key needed
- HTTPS
No authHTTPSNo CORS
32
Times Adder API
Online · 689 ms
With this API you can add each of the times introduced in the array sended.
- No API key needed
- HTTPS
No authHTTPSNo CORS
33
USGS Water Services API
Online · 917 ms
Water quality and level info for rivers and lakes.
- No API key needed
- HTTPS
No authHTTPSNo CORS
34
World Bank API
Online · 822 ms
World Data. A free science & math API by World Bank Data Help Desk.
- No API key needed
- HTTPS
No authHTTPSNo CORS
35
WoRMS API
Online · 553 ms
Marine species taxonomy, synonyms and distributions.
- No API key needed
- HTTPS
No authHTTPSNo CORS
36 $CodeCogs logo$
CodeCogs API
Online · 2199 ms
Render LaTeX equations in PNG, GIF, SVG, EMF, PDF, JSON, or download formats with styling options.
- No API key needed
- HTTPS
No authHTTPSCORS ?
37I
ISRO API
Online · 430 ms
ISRO Space Crafts Information. A free science & math API by ISRO-API.
- No API key needed
- HTTPS
No authHTTPSNo CORS
38
ITIS API
Online · 1391 ms
The Integrated Taxonomic Information System (ITIS, www.itis.gov) partners with specialists from around the world to assemble scientific names and their taxonomic relationships and distributes that data openly through publicly available software.
- No API key needed
- HTTPS
No authHTTPSCORS ?
39
KEGG API
Online · 1825 ms
Genes, pathways, compounds and reactions.
- No API key needed
- HTTPS
No authHTTPSCORS ?
40N
Newton API
Online · 1046 ms
Symbolic and Arithmetic Math Calculator.
- No API key needed
- HTTPS
No authHTTPSNo CORS
41
SpaceX API
Online · 1186 ms
GraphQL, Company, Ships, launchpad and launch data.
- No API key needed
- HTTPS
No authHTTPSCORS ?
42
TLE API
Online · 633 ms
TLE API provides up to date NORAD two line element sets for number of Earth orbiting satellites.
- No API key needed
- HTTPS
No authHTTPSNo CORS
43
USGS Earthquake Hazards Program API
Online · 578 ms
USGS Earthquake Hazards Program, responsible for monitoring, reporting, and researching earthquakes and earthquake hazards.
- No API key needed
- HTTPS
No authHTTPSNo CORS
44
NASA API
Online · 1439 ms
NASA data, including imagery. A free science & math API by NASA Open APIs.
- No API key needed
- HTTPS
No authHTTPSNo CORS
45
Semantic Scholar API
Online · 1615 ms
Academic search engine for papers, authors, and citations.
- No API key needed
- HTTPS
No authHTTPSCORS ?
46M
Minor Planet Center API
Online · 295 ms
Asterank.com Information. A free science & math API by Asterank.
- No API key needed
- Fast: 295 ms response
No authNo HTTPSCORS ?
47O
Open Notify API
Online · 643 ms
ISS astronauts, current location, etc.
- No API key needed
No authNo HTTPSNo CORS
48
Botlero API
Last check failed
Sourced, quoted specs for humanoid robots.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
49X
xMath API
Last check failed
Random mathematical expressions. A free science & math API by x-math.herokuapp.com.
- No API key needed
- Callable from the browser (CORS)
- HTTPS
No authHTTPSCORS
50N
Noctua API
Last check failed
REST API used to access NoctuaSky features.
- No API key needed
- HTTPS
No authHTTPSCORS ?
51O
Ocean Facts API
Last check failed
Facts pertaining to the physical science of Oceanography.
- No API key needed
- HTTPS
No authHTTPSCORS ?

Keyless Science & Math APIs compared

Science & Math APIs with no API key
API	API key	HTTPS	CORS	Uptime	Response	Rating
GBIF	No	Yes	Yes	Up	115 ms	Not rated
Macrostrat	No	Yes	Yes	Up	694 ms	Not rated
Chempirical	No	Yes	Yes	Up	533 ms	Not rated
CycleCalcs	No	Yes	Yes	Up	714 ms	Not rated
Europe PMC	No	Yes	Yes	Up	118 ms	Not rated
iNaturalist	No	Yes	Yes	Up	1121 ms	Not rated
Launch Library 2	No	Yes	Yes	Up	876 ms	Not rated
MathJS	No	Yes	Yes	Up	934 ms	Not rated
Oliver's mTOR Atlas	No	Yes	Yes	Up	739 ms	Not rated
OpenAlex	No	Yes	Yes	Up	864 ms	Not rated
Remote Calc	No	Yes	Yes	Up	661 ms	Not rated
Tallytopia	No	Yes	Yes	Up	420 ms	Not rated
Unpaywall	No	Yes	Yes	Up	654 ms	Not rated
ENA	No	Yes	Yes	Up	564 ms	Not rated
MyGene.info	No	Yes	Yes	Up	1048 ms	Not rated
NCBI E-utilities	No	Yes	Yes	Up	473 ms	Not rated
OBIS	No	Yes	Yes	Up	834 ms	Not rated
RCSB PDB	No	Yes	Yes	Up	865 ms	Not rated
Solar System OpenData	No	Yes	Yes	Up	500 ms	Not rated
DataCite	No	Yes	Yes	Up	1239 ms	Not rated
Open Science Framework	No	Yes	Unknown	Up	361 ms	Not rated
arXiv	No	Yes	Unknown	Up	445 ms	Not rated
iDigBio	No	Yes	Unknown	Up	673 ms	Not rated
inspirehep.net	No	Yes	Unknown	Up	691 ms	Not rated
isEven (humor)	No	Yes	Unknown	Up	804 ms	Not rated
Purple Air	No	Yes	Unknown	Up	890 ms	Not rated
arcsecond.io	No	Yes	Unknown	Up	717 ms	Not rated
SatNOGS	No	Yes	Unknown	Up	518 ms	Not rated
SHARE	No	Yes	No	Up	764 ms	Not rated
SpaceX	No	Yes	No	Up	522 ms	Not rated
Sunrise and Sunset	No	Yes	No	Up	1065 ms	Not rated
Times Adder	No	Yes	No	Up	689 ms	Not rated
USGS Water Services	No	Yes	No	Up	917 ms	Not rated
World Bank	No	Yes	No	Up	822 ms	Not rated
WoRMS	No	Yes	No	Up	553 ms	Not rated
$CodeCogs logo$ CodeCogs	No	Yes	Unknown	Up	2199 ms	Not rated
ISRO	No	Yes	No	Up	430 ms	Not rated
ITIS	No	Yes	Unknown	Up	1391 ms	Not rated
KEGG	No	Yes	Unknown	Up	1825 ms	Not rated
Newton	No	Yes	No	Up	1046 ms	Not rated
SpaceX	No	Yes	Unknown	Up	1186 ms	Not rated
TLE	No	Yes	No	Up	633 ms	Not rated
USGS Earthquake Hazards Program	No	Yes	No	Up	578 ms	Not rated
NASA	No	Yes	No	Up	1439 ms	Not rated
Semantic Scholar	No	Yes	Unknown	Up	1615 ms	Not rated
Minor Planet Center	No	No	Unknown	Up	295 ms	Not rated
Open Notify	No	No	No	Up	643 ms	Not rated
Botlero	No	Yes	Yes	Down	–	Not rated
xMath	No	Yes	Yes	Down	–	Not rated
Noctua	No	Yes	Unknown	Down	–	Not rated
Ocean Facts	No	Yes	Unknown	Down	–	Not rated

FAQ

Are there free Science & Math APIs without an API key?

Yes. 51 free Science & Math APIs need no API key or sign-up, including GBIF API, Macrostrat API and Chempirical API. You can send a request straight away.

Which keyless Science & Math APIs can I call from JavaScript in the browser?

22 of them also support CORS, including GBIF API, Macrostrat API and Chempirical API, so a plain fetch from a web page works.

Do APIs without a key have limits?

Usually, yes. Keyless APIs typically rate-limit by IP address, so cache responses and avoid tight loops. For production traffic, an API with a free key tier often gives higher, more predictable limits.