diff --git a/src/cmd/go/internal/test/test.go b/src/cmd/go/internal/test/test.go
index 86b66c226f..6ec32dfa1e 100644
--- a/src/cmd/go/internal/test/test.go
+++ b/src/cmd/go/internal/test/test.go
@@ -847,6 +847,17 @@ func runTest(ctx context.Context, cmd *base.Command, args []string) {
 		prints = append(prints, printTest)
 	}
 
+	// Order runs for coordinating start JSON prints.
+	ch := make(chan struct{})
+	close(ch)
+	for _, a := range runs {
+		if r, ok := a.Actor.(*runTestActor); ok {
+			r.prev = ch
+			ch = make(chan struct{})
+			r.next = ch
+		}
+	}
+
 	// Ultimately the goal is to print the output.
 	root := &work.Action{Mode: "go test", Actor: work.ActorFunc(printExitStatus), Deps: prints}
 
@@ -884,9 +895,21 @@ var windowsBadWords = []string{
 func builderTest(b *work.Builder, ctx context.Context, pkgOpts load.PackageOpts, p *load.Package, imported bool) (buildAction, runAction, printAction *work.Action, err error) {
 	if len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
 		build := b.CompileAction(work.ModeBuild, work.ModeBuild, p)
-		run := &work.Action{Mode: "test run", Package: p, Deps: []*work.Action{build}}
+		run := &work.Action{
+			Mode:       "test run",
+			Actor:      new(runTestActor),
+			Deps:       []*work.Action{build},
+			Package:    p,
+			IgnoreFail: true, // run (prepare output) even if build failed
+		}
 		addTestVet(b, p, run, nil)
-		print := &work.Action{Mode: "test print", Actor: work.ActorFunc(builderNoTest), Package: p, Deps: []*work.Action{run}}
+		print := &work.Action{
+			Mode:       "test print",
+			Actor:      work.ActorFunc(builderPrintTest),
+			Deps:       []*work.Action{run},
+			Package:    p,
+			IgnoreFail: true, // print even if test failed
+		}
 		return build, run, print, nil
 	}
 
@@ -1013,14 +1036,14 @@ func builderTest(b *work.Builder, ctx context.Context, pkgOpts load.PackageOpts,
 		vetRunAction = printAction
 	} else {
 		// run test
-		c := new(runCache)
+		r := new(runTestActor)
 		runAction = &work.Action{
 			Mode:       "test run",
-			Actor:      work.ActorFunc(c.builderRunTest),
+			Actor:      r,
 			Deps:       []*work.Action{buildAction},
 			Package:    p,
 			IgnoreFail: true, // run (prepare output) even if build failed
-			TryCache:   c.tryCache,
+			TryCache:   r.c.tryCache,
 			Objdir:     testDir,
 		}
 		vetRunAction = runAction
@@ -1080,6 +1103,16 @@ var noTestsToRun = []byte("\ntesting: warning: no tests to run\n")
 var noFuzzTestsToFuzz = []byte("\ntesting: warning: no fuzz tests to fuzz\n")
 var tooManyFuzzTestsToFuzz = []byte("\ntesting: warning: -fuzz matches more than one fuzz test, won't fuzz\n")
 
+// runTestActor is the actor for running a test.
+type runTestActor struct {
+	c runCache
+
+	// sequencing of json start messages, to preserve test order
+	prev <-chan struct{} // wait to start until prev is closed
+	next chan<- struct{} // close next once the next test can start.
+}
+
+// runCache is the cache for running a single test.
 type runCache struct {
 	disableCache bool // cache should be disabled for this run
 
@@ -1103,14 +1136,19 @@ func (lockedStdout) Write(b []byte) (int, error) {
 	return os.Stdout.Write(b)
 }
 
-// builderRunTest is the action for running a test binary.
-func (c *runCache) builderRunTest(b *work.Builder, ctx context.Context, a *work.Action) error {
+func (r *runTestActor) Act(b *work.Builder, ctx context.Context, a *work.Action) error {
+	// Wait for previous test to get started and print its first json line.
+	<-r.prev
+
 	if a.Failed {
 		// We were unable to build the binary.
 		a.Failed = false
 		a.TestOutput = new(bytes.Buffer)
 		fmt.Fprintf(a.TestOutput, "FAIL\t%s [build failed]\n", a.Package.ImportPath)
 		base.SetExitStatus(1)
+
+		// release next test to start
+		close(r.next)
 		return nil
 	}
 
@@ -1125,6 +1163,14 @@ func (c *runCache) builderRunTest(b *work.Builder, ctx context.Context, a *work.
 		stdout = json
 	}
 
+	// Release next test to start (test2json.NewConverter writes the start event).
+	close(r.next)
+
+	if p := a.Package; len(p.TestGoFiles)+len(p.XTestGoFiles) == 0 {
+		fmt.Fprintf(stdout, "?   \t%s\t[no test files]\n", p.ImportPath)
+		return nil
+	}
+
 	var buf bytes.Buffer
 	if len(pkgArgs) == 0 || testBench != "" || testFuzz != "" {
 		// Stream test output (no buffering) when no package has
@@ -1155,7 +1201,7 @@ func (c *runCache) builderRunTest(b *work.Builder, ctx context.Context, a *work.
 		}
 	}
 
-	if c.buf == nil {
+	if r.c.buf == nil {
 		// We did not find a cached result using the link step action ID,
 		// so we ran the link step. Try again now with the link output
 		// content ID. The attempt using the action ID makes sure that
@@ -1165,20 +1211,20 @@ func (c *runCache) builderRunTest(b *work.Builder, ctx context.Context, a *work.
 		// we have different link inputs but the same final binary,
 		// we still reuse the cached test result.
 		// c.saveOutput will store the result under both IDs.
-		c.tryCacheWithID(b, a, a.Deps[0].BuildContentID())
+		r.c.tryCacheWithID(b, a, a.Deps[0].BuildContentID())
 	}
-	if c.buf != nil {
+	if r.c.buf != nil {
 		if stdout != &buf {
-			stdout.Write(c.buf.Bytes())
-			c.buf.Reset()
+			stdout.Write(r.c.buf.Bytes())
+			r.c.buf.Reset()
 		}
-		a.TestOutput = c.buf
+		a.TestOutput = r.c.buf
 		return nil
 	}
 
 	execCmd := work.FindExecCmd()
 	testlogArg := []string{}
-	if !c.disableCache && len(execCmd) == 0 {
+	if !r.c.disableCache && len(execCmd) == 0 {
 		testlogArg = []string{"-test.testlogfile=" + a.Objdir + "testlog.txt"}
 	}
 	panicArg := "-test.paniconexit0"
@@ -1319,7 +1365,7 @@ func (c *runCache) builderRunTest(b *work.Builder, ctx context.Context, a *work.
 			cmd.Stdout.Write([]byte("\n"))
 		}
 		fmt.Fprintf(cmd.Stdout, "ok  \t%s\t%s%s%s\n", a.Package.ImportPath, t, coveragePercentage(out), norun)
-		c.saveOutput(a)
+		r.c.saveOutput(a)
 	} else {
 		base.SetExitStatus(1)
 		if len(out) == 0 {
@@ -1749,18 +1795,6 @@ func builderPrintTest(b *work.Builder, ctx context.Context, a *work.Action) erro
 	return nil
 }
 
-// builderNoTest is the action for testing a package with no test files.
-func builderNoTest(b *work.Builder, ctx context.Context, a *work.Action) error {
-	var stdout io.Writer = os.Stdout
-	if testJSON {
-		json := test2json.NewConverter(lockedStdout{}, a.Package.ImportPath, test2json.Timestamp)
-		defer json.Close()
-		stdout = json
-	}
-	fmt.Fprintf(stdout, "?   \t%s\t[no test files]\n", a.Package.ImportPath)
-	return nil
-}
-
 // printExitStatus is the action for printing the final exit status.
 // If we are running multiple test targets, print a final "FAIL"
 // in case a failure in an early package has already scrolled
diff --git a/src/cmd/go/testdata/script/test_json.txt b/src/cmd/go/testdata/script/test_json.txt
index f2bee34ce2..6207c2efd4 100644
--- a/src/cmd/go/testdata/script/test_json.txt
+++ b/src/cmd/go/testdata/script/test_json.txt
@@ -11,16 +11,22 @@ go test -json -short -v errors m/empty/pkg m/skipper
 
 # Check errors for run action
 stdout '"Package":"errors"'
+stdout '"Action":"start","Package":"errors"'
 stdout '"Action":"run","Package":"errors"'
 
 # Check m/empty/pkg for output and skip actions
+stdout '"Action":"start","Package":"m/empty/pkg"'
 stdout '"Action":"output","Package":"m/empty/pkg","Output":".*no test files'
 stdout '"Action":"skip","Package":"m/empty/pkg"'
 
 # Check skipper for output and skip actions
+stdout '"Action":"start","Package":"m/skipper"'
 stdout '"Action":"output","Package":"m/skipper","Test":"Test","Output":"--- SKIP:'
 stdout '"Action":"skip","Package":"m/skipper","Test":"Test"'
 
+# Check that starts were ordered properly.
+stdout '(?s)"Action":"start","Package":"errors".*"Action":"start","Package":"m/empty/pkg".*"Action":"start","Package":"m/skipper"'
+
 # Run go test -json on errors and check it's cached
 go test -json -short -v errors
 stdout '"Action":"output","Package":"errors","Output":".*\(cached\)'
diff --git a/src/cmd/internal/test2json/test2json.go b/src/cmd/internal/test2json/test2json.go
index 807dcc5102..f7dfbe69d7 100644
--- a/src/cmd/internal/test2json/test2json.go
+++ b/src/cmd/internal/test2json/test2json.go
@@ -119,6 +119,7 @@ func NewConverter(w io.Writer, pkg string, mode Mode) *Converter {
 			part: c.writeOutputEvent,
 		},
 	}
+	c.writeEvent(&event{Action: "start"})
 	return c
 }
 
@@ -131,7 +132,9 @@ func (c *Converter) Write(b []byte) (int, error) {
 // Exited marks the test process as having exited with the given error.
 func (c *Converter) Exited(err error) {
 	if err == nil {
-		c.result = "pass"
+		if c.result != "skip" {
+			c.result = "pass"
+		}
 	} else {
 		c.result = "fail"
 	}
diff --git a/src/cmd/internal/test2json/testdata/ascii.json b/src/cmd/internal/test2json/testdata/ascii.json
index 67fccfc112..94695a10c5 100644
--- a/src/cmd/internal/test2json/testdata/ascii.json
+++ b/src/cmd/internal/test2json/testdata/ascii.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestAscii"}
 {"Action":"output","Test":"TestAscii","Output":"=== RUN   TestAscii\n"}
 {"Action":"output","Test":"TestAscii","Output":"I can eat glass, and it doesn't hurt me. I can eat glass, and it doesn't hurt me.\n"}
diff --git a/src/cmd/internal/test2json/testdata/bench.json b/src/cmd/internal/test2json/testdata/bench.json
index 69e417eb14..102e189ed7 100644
--- a/src/cmd/internal/test2json/testdata/bench.json
+++ b/src/cmd/internal/test2json/testdata/bench.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"output","Output":"goos: darwin\n"}
 {"Action":"output","Output":"goarch: 386\n"}
 {"Action":"output","Output":"BenchmarkFoo-8   \t2000000000\t         0.00 ns/op\n"}
diff --git a/src/cmd/internal/test2json/testdata/benchfail.json b/src/cmd/internal/test2json/testdata/benchfail.json
index ad3ac9e179..d2d968191c 100644
--- a/src/cmd/internal/test2json/testdata/benchfail.json
+++ b/src/cmd/internal/test2json/testdata/benchfail.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"output","Test":"BenchmarkFoo","Output":"--- FAIL: BenchmarkFoo\n"}
 {"Action":"output","Test":"BenchmarkFoo","Output":"\tx_test.go:8: My benchmark\n"}
 {"Action":"fail","Test":"BenchmarkFoo"}
diff --git a/src/cmd/internal/test2json/testdata/benchshort.json b/src/cmd/internal/test2json/testdata/benchshort.json
index 34b03b9362..6c4e193573 100644
--- a/src/cmd/internal/test2json/testdata/benchshort.json
+++ b/src/cmd/internal/test2json/testdata/benchshort.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"output","Output":"# This file ends in an early EOF to trigger the Benchmark prefix test,\n"}
 {"Action":"output","Output":"# which only happens when a benchmark prefix is seen ahead of the \\n.\n"}
 {"Action":"output","Output":"# Normally that's due to the benchmark running and the \\n coming later,\n"}
diff --git a/src/cmd/internal/test2json/testdata/empty.json b/src/cmd/internal/test2json/testdata/empty.json
index e69de29bb2..198f8d7b55 100644
--- a/src/cmd/internal/test2json/testdata/empty.json
+++ b/src/cmd/internal/test2json/testdata/empty.json
@@ -0,0 +1 @@
+{"Action":"start"}
diff --git a/src/cmd/internal/test2json/testdata/frame.json b/src/cmd/internal/test2json/testdata/frame.json
index d2a65fc36b..9dd29ae977 100644
--- a/src/cmd/internal/test2json/testdata/frame.json
+++ b/src/cmd/internal/test2json/testdata/frame.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestAscii"}
 {"Action":"output","Test":"TestAscii","Output":"=== RUN   TestAscii\n"}
 {"Action":"output","Test":"TestAscii","Output":"=== RUN   TestNotReally\n"}
diff --git a/src/cmd/internal/test2json/testdata/framebig.json b/src/cmd/internal/test2json/testdata/framebig.json
index ebb9bdf3f1..54a8a524fe 100644
--- a/src/cmd/internal/test2json/testdata/framebig.json
+++ b/src/cmd/internal/test2json/testdata/framebig.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestIndex"}
 {"Action":"output","Test":"TestIndex","Output":"=== RUN   TestIndex\n"}
 {"Action":"output","Test":"TestIndex","Output":"--- PASS: TestIndex (0.00s)\n"}
diff --git a/src/cmd/internal/test2json/testdata/framefuzz.json b/src/cmd/internal/test2json/testdata/framefuzz.json
index ea2eafa717..25869ee740 100644
--- a/src/cmd/internal/test2json/testdata/framefuzz.json
+++ b/src/cmd/internal/test2json/testdata/framefuzz.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestAddrStringAllocs"}
 {"Action":"output","Test":"TestAddrStringAllocs","Output":"=== RUN   TestAddrStringAllocs\n"}
 {"Action":"run","Test":"TestAddrStringAllocs/zero"}
diff --git a/src/cmd/internal/test2json/testdata/issue23036.json b/src/cmd/internal/test2json/testdata/issue23036.json
index 935c0c5fc0..bfdc3e5e0f 100644
--- a/src/cmd/internal/test2json/testdata/issue23036.json
+++ b/src/cmd/internal/test2json/testdata/issue23036.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestActualCase"}
 {"Action":"output","Test":"TestActualCase","Output":"=== RUN   TestActualCase\n"}
 {"Action":"output","Test":"TestActualCase","Output":"--- FAIL: TestActualCase (0.00s)\n"}
diff --git a/src/cmd/internal/test2json/testdata/issue23920.json b/src/cmd/internal/test2json/testdata/issue23920.json
index 28f7bd56ac..17e8de6e91 100644
--- a/src/cmd/internal/test2json/testdata/issue23920.json
+++ b/src/cmd/internal/test2json/testdata/issue23920.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestWithColons"}
 {"Action":"output","Test":"TestWithColons","Output":"=== RUN   TestWithColons\n"}
 {"Action":"run","Test":"TestWithColons/[::1]"}
diff --git a/src/cmd/internal/test2json/testdata/issue29755.json b/src/cmd/internal/test2json/testdata/issue29755.json
index 2e8ba48629..c49bf92ce2 100644
--- a/src/cmd/internal/test2json/testdata/issue29755.json
+++ b/src/cmd/internal/test2json/testdata/issue29755.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestOutputWithSubtest"}
 {"Action":"output","Test":"TestOutputWithSubtest","Output":"=== RUN   TestOutputWithSubtest\n"}
 {"Action":"run","Test":"TestOutputWithSubtest/sub_test"}
diff --git a/src/cmd/internal/test2json/testdata/panic.json b/src/cmd/internal/test2json/testdata/panic.json
index f7738142e6..1cd4384629 100644
--- a/src/cmd/internal/test2json/testdata/panic.json
+++ b/src/cmd/internal/test2json/testdata/panic.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"output","Test":"TestPanic","Output":"--- FAIL: TestPanic (0.00s)\n"}
 {"Action":"output","Test":"TestPanic","Output":"panic: oops [recovered]\n"}
 {"Action":"output","Test":"TestPanic","Output":"\tpanic: oops\n"}
diff --git a/src/cmd/internal/test2json/testdata/smiley.json b/src/cmd/internal/test2json/testdata/smiley.json
index f49180d520..858843f3af 100644
--- a/src/cmd/internal/test2json/testdata/smiley.json
+++ b/src/cmd/internal/test2json/testdata/smiley.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"Test☺☹"}
 {"Action":"output","Test":"Test☺☹","Output":"=== RUN   Test☺☹\n"}
 {"Action":"output","Test":"Test☺☹","Output":"=== PAUSE Test☺☹\n"}
diff --git a/src/cmd/internal/test2json/testdata/timeout.json b/src/cmd/internal/test2json/testdata/timeout.json
index 162a5bde44..dc225262f7 100644
--- a/src/cmd/internal/test2json/testdata/timeout.json
+++ b/src/cmd/internal/test2json/testdata/timeout.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"Test"}
 {"Action":"output","Test":"Test","Output":"=== RUN   Test\n"}
 {"Action":"output","Test":"Test","Output":"panic: test timed out after 1s\n"}
diff --git a/src/cmd/internal/test2json/testdata/unicode.json b/src/cmd/internal/test2json/testdata/unicode.json
index 9cfb5f2d49..2cc3e7322d 100644
--- a/src/cmd/internal/test2json/testdata/unicode.json
+++ b/src/cmd/internal/test2json/testdata/unicode.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestUnicode"}
 {"Action":"output","Test":"TestUnicode","Output":"=== RUN   TestUnicode\n"}
 {"Action":"output","Test":"TestUnicode","Output":"Μπορώ να φάω σπασμένα γυαλιά χωρίς να πάθω τίποτα. Μπορώ να φάω σπασμένα γυαλιά χωρίς να πάθω τίποτα.\n"}
diff --git a/src/cmd/internal/test2json/testdata/vet.json b/src/cmd/internal/test2json/testdata/vet.json
index 2558d61e74..5b09104522 100644
--- a/src/cmd/internal/test2json/testdata/vet.json
+++ b/src/cmd/internal/test2json/testdata/vet.json
@@ -1,3 +1,4 @@
+{"Action":"start"}
 {"Action":"run","Test":"TestVet"}
 {"Action":"output","Test":"TestVet","Output":"=== RUN   TestVet\n"}
 {"Action":"output","Test":"TestVet","Output":"=== PAUSE TestVet\n"}
diff --git a/src/cmd/test2json/main.go b/src/cmd/test2json/main.go
index 06648b1a9c..09d5fcec79 100644
--- a/src/cmd/test2json/main.go
+++ b/src/cmd/test2json/main.go
@@ -48,6 +48,7 @@
 //
 // The Action field is one of a fixed set of action descriptions:
 //
+//	start  - the test binary is about to be executed
 //	run    - the test has started running
 //	pause  - the test has been paused
 //	cont   - the test has continued running
@@ -57,6 +58,8 @@
 //	output - the test printed output
 //	skip   - the test was skipped or the package contained no tests
 //
+// Every JSON stream begins with a "start" event.
+//
 // The Package field, if present, specifies the package being tested.
 // When the go command runs parallel tests in -json mode, events from
 // different tests are interlaced; the Package field allows readers to