Skip to content
NASA ADS logo

Is NASA ADS API down?

Current status, daily uptime history and troubleshooting for the NASA ADS API (Science & Math).

No, NASA ADS is up

NASA ADS answered our last daily check (Oct 24, 2026, 12:25 UTC) in 1025 ms with HTTP 202.

Checking NASA ADS now…

Sending a request from our server.

NASA ADS API uptime history

30 days agoLatest check
Uptime
2 checks so far
Last check
Oct 24, 2026, 12:25 UTC
Response
1025 ms · HTTP 202
Last up
Now

We check NASA ADS's listed URL (https://ui.adsabs.harvard.edu/help/api/api-docs.html) once a day. History started when NASA ADS was first checked, so new entries show fewer than 30 days.

NASA ADS API not working for you?

  1. NASA ADS needs OAuth. A 401 or 403 usually means a missing, expired or mis-sent credential: check whether it belongs in a header or the query string.
  2. A 429 response means you're being rate-limited. Slow down, cache responses, and respect any Retry-After header.
  3. If it works from one network but not another, check firewalls, VPNs and regional blocks.
  4. Check the provider's documentation, status page or social accounts for planned maintenance or a changed endpoint.

Science & Math APIs up at their last check

  1. 1GBIF logo

    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. 2Macrostrat logo

    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. 3Chempirical logo

    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. 4CycleCalcs logo

    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. 5Europe PMC logo

    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

Compare all NASA ADS alternatives · APIs down right now

NASA ADS API status FAQ

Is NASA ADS API down right now?

NASA ADS answered our last daily check (Oct 24, 2026, 12:25 UTC) in 1025 ms with HTTP 202. This page also runs a live check from our server when you open it, so you can see whether NASA ADS is responding at this moment.

How do you check whether NASA ADS API is up?

Once a day our checker requests NASA ADS's listed URL (https://ui.adsabs.harvard.edu/help/api/api-docs.html) and records whether it answers within 15 seconds. Answers like 401 (needs a key), 403 (blocks bots) or 429 (rate-limited) count as up, because the server responded. The listed URL is often the documentation page, so an API endpoint can occasionally fail while its docs stay up.

What can I use if NASA ADS API is down?

Free Science & Math APIs that were up at their last check include GBIF, Macrostrat, Chempirical. See the full list of NASA ADS alternatives for a comparison.

Why does NASA ADS API work for others but not for me?

NASA ADS needs OAuth. A 401 or 403 usually means a missing, expired or mis-sent credential: check whether it belongs in a header or the query string. A 429 response means you're being rate-limited. Slow down, cache responses, and respect any Retry-After header. If it works from one network but not another, check firewalls, VPNs and regional blocks.