diff --git a/internal/check-filter-width-stable.mjs b/internal/check-filter-width-stable.mjs
index c997a9fe2..4748f300c 100644
--- a/internal/check-filter-width-stable.mjs
+++ b/internal/check-filter-width-stable.mjs
@@ -111,10 +111,27 @@ for (const [label, path, tab] of [
 await browser.close()
 
 let failed = 0
+let unreachable = 0
+// ★ AN ABSENT SERVER IS NOT A PRODUCT FINDING, A MISSING CONTROL IS.
+// The rule below ("an unmeasured host is a failure") is right and is kept: if the page loads and
+// the trigger or tab cannot be found, the gate has been structurally defeated and must say so.
+// But it was also firing when nothing had been measured AT ALL because no server was running —
+// ERR_CONNECTION_REFUSED on :4173 printed "UNMEASURED" twice and then "FAIL — 2 host(s)". That
+// accuses the product of a width regression on the strength of a missing process, and it cost a
+// real misreading during this flight: the gate was reported as failing when it had simply never run.
+// Every other browser gate in this repo already separates the two and says so in the same words —
+// check-fits-the-screen, interop-harness, check-catalog-identity and check-legend-matches-source all
+// print "SKIP — ... unreachable right now. Not a product finding." This one was the outlier.
+const isUnreachable = (e) => /ERR_CONNECTION_REFUSED|ERR_CONNECTION_RESET|ECONNREFUSED|net::ERR_|ERR_EMPTY_RESPONSE/i.test(String(e))
 console.log('FILTER-WIDTH: a trigger must not resize when an option is selected\n')
 for (const h of hosts) {
   console.log(`--- ${h.label} ---`)
   if (h.error) {
+    if (isUnreachable(h.error)) {
+      console.log('  UNREACHABLE: ' + h.error)
+      unreachable++
+      continue
+    }
     // An unmeasured host is a failure. A gate that quietly drops a host reports success about
     // something it never looked at.
     console.log('  UNMEASURED: ' + h.error)
@@ -133,6 +150,11 @@ for (const h of hosts) {
   }
 }
 
+if (!failed && unreachable === hosts.length) {
+  console.log(`FILTER-WIDTH: SKIP — all ${hosts.length} host(s) unreachable. Not a product finding.`)
+  console.log('  Start a server first: `bun run serve` (or set BASE_URL).')
+  process.exit(0)
+}
 if (failed) {
   console.error(`FILTER-WIDTH: FAIL — ${failed} host(s).`)
   console.error('  A trigger that grows on selection re-flows the selections row beneath it, so the')