CongressInvests vs Marketstack
Same instrument, two spec sheets — measured, not claimed.
CongressInvests vs Marketstack: common questions
Which is more reliable, CongressInvests or Marketstack?
Both are neck-and-neck — CongressInvests and Marketstack each measure 100% uptime over 90 days on our probe schedule. Reliability here is verified from our own scheduled checks; use the 30-day bars above to see which has been steadier lately.
Which is faster, CongressInvests or Marketstack?
Marketstack has the lower median latency in our checks — CongressInvests responds in 615 ms versus Marketstack at 470 ms (P50). Tail latency (P95) is in the table above; for most workloads the median is the number that shapes how the API feels.
Do CongressInvests and Marketstack need an API key?
Both ask you to authenticate — CongressInvests uses an API key and Marketstack uses an API key. Each key is free to obtain; the Auth and Card-required rows above spell out the signup terms.
Can I call CongressInvests and Marketstack from the browser?
Only CongressInvests is browser-friendly — it returns CORS headers over HTTPS. Marketstack needs a server-side call or proxy, so factor that into which one fits a front-end project.
Are CongressInvests and Marketstack free for commercial use?
CongressInvests has unclear commercial terms, and Marketstack has unclear commercial terms. We track service terms and the data license as separate fields — see the Commercial use and Data license rows above, and confirm both before shipping either in a paid product.