diff --git a/web_src/js/components/RepoActionView.test.ts b/web_src/js/components/RepoActionView.test.ts
new file mode 100644
index 0000000000..0bbd739206
--- /dev/null
+++ b/web_src/js/components/RepoActionView.test.ts
@@ -0,0 +1,110 @@
+// Test for workflow command line filtering logic
+
+// These are the constants and functions from RepoActionView.vue
+const LogLinePrefixesHidden = ['::add-matcher::', '##[add-matcher]', '::workflow-command', '::remove-matcher'];
+
+type LogLine = {
+  index: number;
+  timestamp: number;
+  message: string;
+};
+
+function shouldHideLine(line: LogLine): boolean {
+  for (const prefix of LogLinePrefixesHidden) {
+    if (line.message.startsWith(prefix)) {
+      return true;
+    }
+  }
+  return false;
+}
+
+test('shouldHideLine filters workflow commands starting with ::add-matcher::', () => {
+  const line: LogLine = {
+    index: 1,
+    timestamp: 1000,
+    message: '::add-matcher::.github/problem-matcher.json',
+  };
+  expect(shouldHideLine(line)).toBe(true);
+});
+
+test('shouldHideLine filters workflow commands starting with ##[add-matcher]', () => {
+  const line: LogLine = {
+    index: 2,
+    timestamp: 1001,
+    message: '##[add-matcher].github/eslint.json',
+  };
+  expect(shouldHideLine(line)).toBe(true);
+});
+
+test('shouldHideLine filters workflow commands starting with ::workflow-command', () => {
+  const line: LogLine = {
+    index: 3,
+    timestamp: 1002,
+    message: '::workflow-command::some-command',
+  };
+  expect(shouldHideLine(line)).toBe(true);
+});
+
+test('shouldHideLine filters workflow commands starting with ::remove-matcher', () => {
+  const line: LogLine = {
+    index: 4,
+    timestamp: 1003,
+    message: '::remove-matcher::owner=eslint',
+  };
+  expect(shouldHideLine(line)).toBe(true);
+});
+
+test('shouldHideLine does not filter normal log lines', () => {
+  const line: LogLine = {
+    index: 5,
+    timestamp: 1004,
+    message: 'Normal log line without workflow commands',
+  };
+  expect(shouldHideLine(line)).toBe(false);
+});
+
+test('shouldHideLine does not filter lines with workflow commands not at the start', () => {
+  const line: LogLine = {
+    index: 6,
+    timestamp: 1005,
+    message: 'Some text before ::add-matcher:: in the middle',
+  };
+  expect(shouldHideLine(line)).toBe(false);
+});
+
+test('shouldHideLine handles group commands (should not hide them)', () => {
+  const groupLine: LogLine = {
+    index: 7,
+    timestamp: 1006,
+    message: '::group::Build Step',
+  };
+  expect(shouldHideLine(groupLine)).toBe(false);
+  
+  const endGroupLine: LogLine = {
+    index: 8,
+    timestamp: 1007,
+    message: '::endgroup::',
+  };
+  expect(shouldHideLine(endGroupLine)).toBe(false);
+});
+
+test('shouldHideLine handles various log formats', () => {
+  const testCases = [
+    {message: '::add-matcher::', expected: true},
+    {message: '##[add-matcher]', expected: true},
+    {message: '::workflow-command', expected: true},
+    {message: '::remove-matcher', expected: true},
+    {message: 'Build started', expected: false},
+    {message: 'Error: test failed', expected: false},
+    {message: '  ::add-matcher::.github/test.json', expected: false}, // with leading space
+  ];
+
+  testCases.forEach(({message, expected}, index) => {
+    const line: LogLine = {
+      index: index + 10,
+      timestamp: 2000 + index,
+      message,
+    };
+    expect(shouldHideLine(line)).toBe(expected);
+  });
+});
diff --git a/web_src/js/components/RepoActionView.vue b/web_src/js/components/RepoActionView.vue
index 69579d3687..6679ba93ce 100644
--- a/web_src/js/components/RepoActionView.vue
+++ b/web_src/js/components/RepoActionView.vue
@@ -23,6 +23,7 @@ type LogLine = {
 
 const LogLinePrefixesGroup = ['::group::', '##[group]'];
 const LogLinePrefixesEndGroup = ['::endgroup::', '##[endgroup]'];
+const LogLinePrefixesHidden = ['::add-matcher::', '##[add-matcher]', '::workflow-command', '::remove-matcher'];
 
 type LogLineCommand = {
   name: 'group' | 'endgroup',
@@ -63,6 +64,15 @@ function parseLineCommand(line: LogLine): LogLineCommand | null {
   return null;
 }
 
+function shouldHideLine(line: LogLine): boolean {
+  for (const prefix of LogLinePrefixesHidden) {
+    if (line.message.startsWith(prefix)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 function isLogElementInViewport(el: Element, {extraViewPortHeight}={extraViewPortHeight: 0}): boolean {
   const rect = el.getBoundingClientRect();
   // only check whether bottom is in viewport, because the log element can be a log group which is usually tall
@@ -315,6 +325,10 @@ export default defineComponent({
 
     appendLogs(stepIndex: number, startTime: number, logLines: LogLine[]) {
       for (const line of logLines) {
+        // Skip lines that should be hidden (workflow commands)
+        if (shouldHideLine(line)) {
+          continue;
+        }
         const el = this.getActiveLogsContainer(stepIndex);
         const cmd = parseLineCommand(line);
         if (cmd?.name === 'group') {