I checked every MCP server in the official registry. About 1 in 10 is broken.

There is a number going around that roughly half of all remote MCP servers are dead. I had repeated it myself, in the README of a tool I published. I could not find where it came from, so I measured it. The answer is that about one in ten is actually broken. The "half" figure appears to come from counting servers that require an API key as if they were down. Here is the method and the full breakdown. What I measured On 29 July 2026 I pulled every entry from the official MCP registry — 1,200 servers. Of those, 297 had status: active and advertised a remote endpoint URL (the rest are stdio/local packages with nothing to probe over the network). Each got one anonymous JSON-RPC initialize over streamable HTTP, with a 10 second timeout: { "jsonrpc" : "2.0" , "id" : 1 , "method" : "initialize" , "params" : { "protocolVersion" : "2025-06-18" , "capabilities" : {}, "clientInfo" : { "name" : "mcp-uptime" , "version" : "0.1.0" } } } Then I classified the response: a valid result containing protocolVersion or serverInfo is up, 401/403 is auth-gated, and everything else got bucketed by its actual failure. Results (n = 297) Result Count Share Completed an MCP handshake 133 44.8% Auth-gated (401/403) 134 45.1% DNS failure 8 2.7% Server error (5xx) 6 2.0% Not found (404/410) 5 1.7% Redirect (307/308) 4 1.3% Timeout 2 0.7% Non-MCP response 2 0.7% Other (400, 405, connection) 3 1.0% Reachable: 267 (89.9%). Genuinely broken: 30 (10.1%). Where "half are dead" comes from Look at the first two rows. 55.2% of these endpoints will not complete an anonymous handshake — and that is suspiciously close to the number people quote. But 134 of those 164 are returning a clean 401 or 403. They are running. They are answering. They want an API key, which is a completely reasonable thing for a hosted service to want. Counting those as dead inflates the failure rate by roughly five times. This matters beyond pedantry: if you believe half the ecosystem is rubble, you build defensively against the wron