ontologies: List all ontologies

API: ac.uk:embl-ebi-ontology-lookup-service-ols-api
Endpoint: /ontologies
Response format: application/json
Auth: none
Method: GET
Last Status: 200
Latency: 328ms

Description

Returns a paginated list of all available ontologies in the OLS repository.

Parameters (2)

page (integer, query, optional, default: 0)

Page number (0-indexed)

size (integer, query, optional, default: 20)

Page size (number of results per page)

Examples (4)

List ontologies with default pagination curl
curl 'https://www.ebi.ac.uk/ols4/api/ontologies'
import requests

resp = requests.get("https://www.ebi.ac.uk/ols4/api/ontologies")
data = resp.json()
import zingu_apis

api = zingu_apis.api("embl-ebi-ontology-lookup-service-ols")
result = api.fetch("ontologies")

for item in result:
    print(item)
const resp = await fetch("https://www.ebi.ac.uk/ols4/api/ontologies");
const data = await resp.json();
List ontologies with custom page size curl
curl 'https://www.ebi.ac.uk/ols4/api/ontologies?page=0&size=10'
import requests

resp = requests.get(
    "https://www.ebi.ac.uk/ols4/api/ontologies",
    params={
        'page': 0,
        'size': 10,
    },
)
data = resp.json()
import zingu_apis

api = zingu_apis.api("embl-ebi-ontology-lookup-service-ols")
result = api.fetch("ontologies", page=0, size=10)

for item in result:
    print(item)
const resp = await fetch("https://www.ebi.ac.uk/ols4/api/ontologies?page=0&size=10");
const data = await resp.json();
List ontologies on second page with larger size curl
curl 'https://www.ebi.ac.uk/ols4/api/ontologies?page=1&size=50'
import requests

resp = requests.get(
    "https://www.ebi.ac.uk/ols4/api/ontologies",
    params={
        'page': 1,
        'size': 50,
    },
)
data = resp.json()
import zingu_apis

api = zingu_apis.api("embl-ebi-ontology-lookup-service-ols")
result = api.fetch("ontologies", page=1, size=50)

for item in result:
    print(item)
const resp = await fetch("https://www.ebi.ac.uk/ols4/api/ontologies?page=1&size=50");
const data = await resp.json();
List all ontologies probe-gate
curl 'https://www.ebi.ac.uk/ols4/api/ontologies?page=0&size=20'
import requests

resp = requests.get(
    "https://www.ebi.ac.uk/ols4/api/ontologies",
    params={
        'page': '0',
        'size': '20',
    },
)
data = resp.json()
import zingu_apis

api = zingu_apis.api("embl-ebi-ontology-lookup-service-ols")
result = api.fetch("ontologies", page=0, size=20)

for item in result:
    print(item)
const resp = await fetch("https://www.ebi.ac.uk/ols4/api/ontologies?page=0&size=20");
const data = await resp.json();

Probe History

Latency

Status Codes

TimeStatusLatencySize
2026-04-16 04:08:03.810012 200 328ms
2026-04-16 02:34:21.615555 200 218ms
2026-04-16 00:29:14.613304 200 679ms
2026-04-16 00:04:34.318708 200 326ms
2026-04-15 02:27:56.355875 200 227ms
2026-04-15 01:29:22.243865 200 221ms
2026-04-15 01:04:01.775133 200 220ms
2026-04-15 00:43:59.443101 200 320ms
2026-04-14 03:35:37.286928 200 290ms
2026-04-14 03:26:50.495288 200 234ms
2026-04-14 03:15:04.733093 200 303ms
2026-04-14 00:59:39.234522 200 247ms
2026-04-12 15:48:06.832416 200 318ms
2026-04-12 15:34:28.366758 200 238ms
2026-04-12 14:43:30.474868 200 235ms
2026-04-12 13:28:46.521304 200 663ms
2026-04-10 03:18:01.875421 200 442ms
2026-04-10 01:29:59.379640 200 170ms
2026-04-10 01:16:16.267376 200 191ms
2026-04-10 00:06:02.363408 200 180ms
2026-04-09 01:33:32.244108 200 254ms
2026-04-09 01:24:00.849683 200 328ms
2026-04-09 00:37:24.979528 200 474ms
2026-04-09 00:26:53.798272 200 349ms
2026-04-08 07:18:02.249655 200 317ms
2026-04-08 07:09:26.398156 200 255ms
2026-04-08 06:51:24.982601 200 442ms
2026-04-08 00:07:33.001276 200 235ms
2026-04-07 01:26:23.384580 200 230ms
2026-04-07 01:09:20.097212 200 227ms
2026-04-07 00:28:27.265674 200 206ms
2026-04-07 00:27:22.599125 200 248ms
2026-04-06 06:50:10.514995 200 256ms
2026-04-06 06:38:05.572481 200 243ms
2026-04-06 04:44:38.062049 200 516ms
2026-04-06 00:34:25.148547 200 331ms
2026-04-05 15:17:00.398282 ERR
2026-04-05 14:53:16.350619 200 462ms
2026-04-05 14:36:38.013477 200 404ms
2026-03-23 10:47:12.434561 200 144ms
2026-03-23 10:32:25.334139 200 172ms
2026-03-23 10:23:39.626168 200 152ms
2026-03-23 09:20:35.215455 200 174ms