What are the API request limits?

A single IP address can only make a certain number of API requests per day, depending on the presence of a valid API key.

Default API daily limits:

  • Key: 10,000
  • No Key: 300

These limit are per-site, per-day. So, with a legitimate key, you can make 10,000 requests a day to each site which exposes the API.

When should I use a key?

The No Key limit is meant for light experimentation and simple development work. The instant you need the higher limit, it is acceptable to register for a key. Your application does not need to be in a releasable — even an alpha — state. Remember to update your application registration when you do release your app.

I'm building a library, should I include a key?

No, your library should instead take a key to use at initialization.

Remember that using a revoked or invalid key on a request will cause that request to not be completed. Consequently, an abusive application using your library could result in all legitimate applications also using your library being banned from the API.

For development purposes it's fine to register for an API key and use it in, say, a test suite or demo application.

What should I do if I need more requests per day?

Certain types of applications — services and websites, to name two — can legitimately have much higher per-day request requirements than typical applications. If you can demonstrate a need for a higher request quota, contact us.

However, the Key limit should be sufficient for development, so please only request an increased quota when your application is live and has a non-trivial number of users.

What if I share an IP with another [app]?

You should use the authentication feature to acquire a no_expiry access_token tied to your account, and use it for all requests.

  • 3
    These limit are per-site, per-day - is this still true for API v2 where all API calls are through api.stackexchange.com or was it only for when each site had its own API v1 like api.travel.stackexchange.com? At least without a key it seems I use up my "just hacking" limit even when spreading experiments over various sites. – hippietrail Oct 17 '12 at 15:47

You must log in to answer this question.

Browse other questions tagged .