Litport Free Proxy
Live-tested HTTP, SOCKS4, and SOCKS5 proxies with latency, uptime, and geolocation

Live up/down status of 240+ online services, checked every minute from 3 regions.
LiveOrDown API is a free Development API that requires no API key, is served over HTTPS and supports CORS, so it can be called from the browser.
Free JSON API, status badges and outage feeds from LiveOrDown.
Details from liveordown.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Live-tested HTTP, SOCKS4, and SOCKS5 proxies with latency, uptime, and geolocation
Generate logs
Online Lua 5.1 Decompiler
Retrieve vendor details and other information regarding a given MAC address or an OUI
The LiveOrDown API is provided by LiveOrDown (liveordown.com). Free JSON API, status badges and outage feeds from LiveOrDown.
Yes. The LiveOrDown API is listed in the Development category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
No. The LiveOrDown API requires no authentication, so you can start making requests without signing up.
Yes. The LiveOrDown API supports CORS, so front-end JavaScript can call it directly.
Yes. The LiveOrDown API is served over HTTPS, so it's safe to use in production.