Is Circle Down?

How we measure this

• We request Circle's public endpoint every 6 hours from Fly.io regions across six continents — the most recent check ran from 8 of them. When you open this page and our last check is more than 30 minutes old, we check again on the spot; those checks update the verdict, never the availability figures.
• A region counts as down only when it gets no usable HTTP response. A 403 or 429 means the origin answered and refused us, which we report as blocked, never as an outage.
• A single failing region is treated as probe noise. Our checks only change their verdict when two consecutive cycles agree.
• Response times average only the regions that actually served the page, so a timeout never inflates the number.
• Where Circle publishes an official status feed we read it too, and the verdict is the worse of what it reports and what our checks see: a major outage of Circle itself is Down, trouble with one part of it is Degraded, problems at a few of a provider's many locations change nothing, and a security notice that marks nothing down is shown but changes nothing either. We check the feed every 3 minutes and read it again within minutes of any change to its incidents or components; a reading counts for 45 minutes after the last check that found nothing changed. The availability figures above are our measurement alone.