Health & Medical APIs
Free health and medical APIs: drug databases, disease and epidemiology statistics, nutrition data, clinical trials and medical terminology references.
26 tested APIs with full docs · 26 need no key · 36 more listed
Tested, with full documentation
We called each of these before publishing. Every page carries a working curl command, the real JSON response it returned, parameters and common errors.
CDC Environmental Public Health Tracking
Free CDC Environmental Public Health Tracking API with no key: asthma, air quality, drinking water, heat illness, lead poisoning and climate health measures by state and county.
Verified 21 Aug 2026
CDC Open Data
Free CDC Open Data API with no key: hundreds of public health datasets — mortality, life expectancy, chronic disease, environmental health — queryable with SoQL filters.
Verified 21 Aug 2026
NLM Clinical Table Search Service
Free NLM Clinical Table Search Service with no key: autocomplete search over ICD-10-CM, LOINC, RxTerms, HPO, SNOMED conditions and NPI. Built for type-ahead boxes.
Verified 21 Aug 2026
ClinicalTrials.gov
Free ClinicalTrials.gov API with no key: 500,000+ clinical studies worldwide with conditions, interventions, eligibility, locations and results. Tested example.
Verified 19 Aug 2026
ClinPGx (PharmGKB)
Free ClinPGx API, formerly PharmGKB, with no key: pharmacogenomic gene records, allele definitions, CPIC guideline status and drug-gene relationships. No account needed.
Verified 21 Aug 2026
CMS Provider Data Catalog
Free CMS Provider Data Catalog API with no key: hospital, nursing home, hospice and dialysis quality ratings, measure scores and facility details for the United States.
Verified 21 Aug 2026
DailyMed
Free NLM DailyMed API with no key: official FDA-approved drug labels, package inserts, ingredients and packaging for every US medication. Tested example.
Verified 20 Aug 2026
HAPI FHIR Test Server
Free public HAPI FHIR R4 test server with no key: query Patient, Observation, Condition and every other FHIR resource against synthetic data. For development and learning only.
Verified 21 Aug 2026
Health Canada Drug Product Database
Free Health Canada Drug Product Database API with no key: look up any drug authorised for sale in Canada by DIN, brand name or company, with status and ingredient data.
Verified 21 Aug 2026
HealthCare.gov
Free HealthCare.gov API with no key: official US health insurance glossary, articles, topics and guidance content as structured JSON. Tested curl example.
Verified 20 Aug 2026
Human Phenotype Ontology
Free Human Phenotype Ontology API with no key: phenotype term definitions, synonyms, cross-references to SNOMED and UMLS, translations and disease associations.
Verified 21 Aug 2026
ISRCTN Registry
Free ISRCTN registry API with no key: search registered clinical trials and export records in the WHO ICTRP dataset format, with sponsor, design, phase and recruitment status.
Verified 21 Aug 2026
MedlinePlus Connect
Free MedlinePlus Connect API with no key: send an ICD-10-CM, RxCUI, LOINC or SNOMED code and get back consumer health information written for patients, in English or Spanish.
Verified 21 Aug 2026
MedlinePlus Genetics
Free NIH MedlinePlus Genetics API with no key: plain-language summaries of genetic conditions, genes and chromosomes, written for patients and reviewed by experts. Tested example included.
Verified 21 Aug 2026
Monarch Initiative
Free Monarch Initiative API with no key: integrated disease, gene and phenotype records with cross-references to OMIM, Orphanet, ICD-10, MeSH, SNOMED and UMLS.
Verified 21 Aug 2026
MyDisease.info
Free MyDisease.info API with no key: disease annotation aggregated from MONDO, Disease Ontology, HPO, DisGeNET and more, with field selection and batch queries.
Verified 21 Aug 2026
NCI EVS Thesaurus
Free NCI EVS REST API with no key: NCI Thesaurus concepts with synonyms by source, definitions, hierarchies and mappings across cancer research terminologies.
Verified 21 Aug 2026
NHS Organisation Data Service
Free NHS Organisation Data Service API with no key: look up GP practices, hospitals, trusts and other NHS organisations by ODS code, role, postcode or status.
Verified 21 Aug 2026
NHS Scotland Open Data
Free NHS Scotland open data API with no key: hospital activity, waiting times, prescribing and health board reference data through the standard CKAN interface. Tested example included.
Verified 21 Aug 2026
NPI Registry (NPPES)
Free NPPES NPI Registry API with no key: look up any US healthcare provider or organisation by NPI number, name, location or specialty taxonomy. Tested example included.
Verified 21 Aug 2026
openFDA
Free FDA openFDA API with no key: drug labels, adverse event reports, recalls, device and food safety data from official US regulatory records. Tested example.
Verified 19 Aug 2026
Orphadata
Free Orphadata API with no key: Orphanet rare disease records with ICD-10 and ICD-11 mappings, OMIM and MeSH cross-references, and stated mapping relation quality.
Verified 21 Aug 2026
PubChem
Free NIH PubChem API with no key: 100M+ chemical compounds with formulas, molecular weight, structures, synonyms, safety and bioactivity data. Tested.
Verified 20 Aug 2026
NCBI E-utilities (PubMed)
Free NCBI E-utilities API with no key: search 35M+ biomedical citations in PubMed, plus GenBank, protein and other NCBI databases. Tested curl example.
Verified 20 Aug 2026
RxNorm
Free NIH RxNorm API with no key: normalised drug names, ingredients, brand-generic mapping and clinical drug identifiers from the US National Library of Medicine.
Verified 19 Aug 2026
WHO Global Health Observatory
Free World Health Organization API with no key: 2,000+ health indicators by country and year — life expectancy, mortality, immunisation and disease data. Tested.
Verified 19 Aug 2026
Choosing between these Health & Medical APIs
Health APIs cover everything from drug interaction databases to national epidemiology feeds. Several are run by public health bodies such as the FDA and WHO, which makes them stable and citable.
Treat anything clinical with care: these APIs are data sources, not medical advice, and most licences explicitly forbid using them for diagnosis or treatment decisions. Read the terms before building anything patient-facing.
More Health & Medical APIs in the directory
36 further APIs in this category, of which 27 need no API key. These are catalogued from the public-API lists and link straight to each provider's own documentation — we have not tested them yet, so treat the auth and CORS flags as the upstream list's claim rather than ours. They are promoted to a full tested page as we work through them.
| API | What it does | Auth |
|---|---|---|
| Clinical Trials Directory | Every clinical trial registered with ClinicalTrials.gov, indexed by condition and sponsor | NoneCORS |
| CMS.gov | Access to the data from the CMS - medicare.gov | Key |
| Coronavirus | HTTP API for Latest Covid-19 Data | None |
| Coronavirus in the UK | UK Government coronavirus data, including deaths and cases by region | None |
| Covid Tracking Project | Covid-19 data for the US | None |
| Covid-19 | Covid 19 spread, infection and recovery | NoneCORS |
| Covid-19 | Covid 19 cases, deaths and recovery per country | NoneCORS |
| Covid-19 Datenhub | Maps, datasets, applications and more in the context of COVID-19 | None |
| Covid-19 Government Response | Government measures tracker to fight against the Covid-19 pandemic | NoneCORS |
| Covid-19 India | Covid 19 statistics state and district wise about cases, vaccinations, recovery within India | None |
| Covid-19 JHU CSSE | Open-source API for exploring Covid19 cases based on JHU CSSE | NoneCORS |
| Covid-19 Live Data | Global and countrywise data of Covid 19 daily Summary, confirmed cases, recovered and deaths | NoneCORS |
| Covid-19 Philippines | Unofficial Covid-19 Web API for Philippines from data collected by DOH | NoneCORS |
| COVID-19 Tracker Canada | Details on Covid-19 cases across Canada | None |
| COVID-19 Tracker Sri Lanka | Provides situation of the COVID-19 patients reported in Sri Lanka | None |
| COVID-ID | Indonesian government Covid data per province | NoneCORS |
| Cure Cancer With AI | Oncology research, clinical trials, FDA approvals, news, and MAMMAL predictions | Key |
| Dataflow Kit COVID-19 | COVID-19 live statistics into sites per hour | None |
| Edamam | Food and nutrition data API with recipe search | Key |
| ERstat | Live Canadian emergency room closures and service disruptions, by province | KeyCORS |
| FoodData Central | National Nutrient Database for Standard Reference | Key |
| Humanitarian Data Exchange | Humanitarian Data Exchange (HDX) is open platform for sharing data across crises and organisations | None |
| Infermedica | NLP based symptom checker and patient triage API for health diagnosis from text | KeyCORS |
| LAPIS | SARS-CoV-2 genomic sequences from public sources | NoneCORS |
| Lexigram | NLP that extracts mentions of clinical concepts from text, gives access to clinical ontology | Key |
| Longevity World Cup | Public longevity athlete data, biological age calculators and rankings | NoneCORS |
| Makeup | Makeup Information | None |
| MyVaccination | Vaccination data for Malaysia | None |
| NPPES | National Plan & Provider Enumeration System, info on healthcare providers registered in US | None |
| Nutritionix | Worlds largest verified nutrition database | Key |
| Open Data NHS Scotland | Medical reference data and statistics by Public Health Scotland | None |
| Open Disease | API for Current cases and more stuff about COVID-19 and Influenza | NoneCORS |
| Orion Health | Medical platform which allows the development of applications for different healthcare scenarios | OAuth |
| Psychologie et Sérénité | French psychology articles metadata and validated psychological tests catalog | NoneCORS |
| Quarantine | Coronavirus API with free COVID-19 live updates | NoneCORS |
| Verified Supplement Data | Supplement dosing, form comparisons and drug-nutrient interactions with PubMed citations | NoneCORS |
Turn API responses into results
Once the request works you still have to do something with what comes back. These run in your browser, free, with nothing uploaded.
JSON Formatter
Paste a raw response and read it indented, folded and colour-coded.
JSON Path Finder
Click any value to get the path that reaches it in your own code.
JSON to TypeScript
Turn a captured response into typed interfaces before you write the fetch.
CSV to JSON Converter
Turn a spreadsheet into the request body a POST endpoint expects.
Unix Timestamp Converter
Decode the epoch fields almost every API returns.
JWT Decoder
Read the claims and expiry inside a bearer token without pasting it anywhere.
PDF Table to CSV
Pull a table out of a PDF so it can be posted to an API as data.
Event Schema Generator
Publish what an API returns as structured data search engines can read.