diff --git a/pkgs/stack_trace/CHANGELOG.md b/pkgs/stack_trace/CHANGELOG.md
index 1d4eaae..ed1a6c7 100644
--- a/pkgs/stack_trace/CHANGELOG.md
+++ b/pkgs/stack_trace/CHANGELOG.md
@@ -1,4 +1,9 @@
-## 1.3.6
+## 1.4.0
+
+* `new Trace.parse()` and related constructors will no longer throw an exception
+  if they encounter an unparseable stack frame. Instead, they will generate an
+  `UnparsedFrame`, which exposes no metadata but preserves the frame's original
+  text.
 
 * Properly parse native-code V8 frames.
 
diff --git a/pkgs/stack_trace/lib/src/frame.dart b/pkgs/stack_trace/lib/src/frame.dart
index a5fd6ae..072983a 100644
--- a/pkgs/stack_trace/lib/src/frame.dart
+++ b/pkgs/stack_trace/lib/src/frame.dart
@@ -7,6 +7,7 @@
 import 'package:path/path.dart' as path;
 
 import 'trace.dart';
+import 'unparsed_frame.dart';
 
 // #1      Foo._bar (file:///home/nweiz/code/stuff.dart:42:21)
 // #1      Foo._bar (file:///home/nweiz/code/stuff.dart:42)
@@ -126,7 +127,7 @@
   }
 
   /// Parses a string representation of a Dart VM stack frame.
-  factory Frame.parseVM(String frame) {
+  factory Frame.parseVM(String frame) => _catchFormatException(frame, () {
     // The VM sometimes folds multiple stack frames together and replaces them
     // with "...".
     if (frame == '...') {
@@ -134,9 +135,7 @@
     }
 
     var match = _vmFrame.firstMatch(frame);
-    if (match == null) {
-      throw new FormatException("Couldn't parse VM stack trace line '$frame'.");
-    }
+    if (match == null) return new UnparsedFrame(frame);
 
     // Get the pieces out of the regexp match. Function, URI and line should
     // always be found. The column is optional.
@@ -149,14 +148,12 @@
     var line = lineAndColumn.length > 1 ? int.parse(lineAndColumn[1]) : null;
     var column = lineAndColumn.length > 2 ? int.parse(lineAndColumn[2]) : null;
     return new Frame(uri, line, column, member);
-  }
+  });
 
   /// Parses a string representation of a Chrome/V8 stack frame.
-  factory Frame.parseV8(String frame) {
+  factory Frame.parseV8(String frame) => _catchFormatException(frame, () {
     var match = _v8Frame.firstMatch(frame);
-    if (match == null) {
-      throw new FormatException("Couldn't parse V8 stack trace line '$frame'.");
-    }
+    if (match == null) return new UnparsedFrame(frame);
 
     // v8 location strings can be arbitrarily-nested, since it adds a layer of
     // nesting for each eval performed on that line.
@@ -172,10 +169,7 @@
       }
 
       var urlMatch = _v8UrlLocation.firstMatch(location);
-      if (urlMatch == null) {
-        throw new FormatException(
-            "Couldn't parse V8 stack trace line '$frame'.");
-      }
+      if (urlMatch == null) return new UnparsedFrame(frame);
 
       return new Frame(
           _uriOrPathToUri(urlMatch[1]),
@@ -197,7 +191,7 @@
       // functions.
       return parseLocation(match[3], "<fn>");
     }
-  }
+  });
 
   /// Parses a string representation of a JavaScriptCore stack trace.
   factory Frame.parseJSCore(String frame) => new Frame.parseV8(frame);
@@ -209,12 +203,9 @@
   factory Frame.parseIE(String frame) => new Frame.parseV8(frame);
 
   /// Parses a string representation of a Firefox stack frame.
-  factory Frame.parseFirefox(String frame) {
+  factory Frame.parseFirefox(String frame) => _catchFormatException(frame, () {
     var match = _firefoxSafariFrame.firstMatch(frame);
-    if (match == null) {
-      throw new FormatException(
-          "Couldn't parse Firefox/Safari stack trace line '$frame'.");
-    }
+    if (match == null) return new UnparsedFrame(frame);
 
     // Normally this is a URI, but in a jsshell trace it can be a path.
     var uri = _uriOrPathToUri(match[3]);
@@ -237,7 +228,7 @@
     var column = match[5] == null || match[5] == '' ?
         null : int.parse(match[5]);
     return new Frame(uri, line, column, member);
-  }
+  });
 
   /// Parses a string representation of a Safari 6.0 stack frame.
   @Deprecated("Use Frame.parseSafari instead.")
@@ -251,7 +242,7 @@
   factory Frame.parseSafari(String frame) => new Frame.parseFirefox(frame);
 
   /// Parses this package's string representation of a stack frame.
-  factory Frame.parseFriendly(String frame) {
+  factory Frame.parseFriendly(String frame) => _catchFormatException(frame, () {
     var match = _friendlyFrame.firstMatch(frame);
     if (match == null) {
       throw new FormatException(
@@ -268,7 +259,7 @@
     var line = match[2] == null ? null : int.parse(match[2]);
     var column = match[3] == null ? null : int.parse(match[3]);
     return new Frame(uri, line, column, match[4]);
-  }
+  });
 
   /// A regular expression matching an absolute URI.
   static final _uriRegExp = new RegExp(r'^[a-zA-Z][-+.a-zA-Z\d]*://');
@@ -294,6 +285,18 @@
     return Uri.parse(uriOrPath);
   }
 
+  /// Runs [body] and returns its result.
+  ///
+  /// If [body] throws a [FormatException], returns an [UnparsedFrame] with
+  /// [text] instead.
+  static Frame _catchFormatException(String text, Frame body()) {
+    try {
+      return body();
+    } on FormatException catch (_) {
+      return new UnparsedFrame(text);
+    }
+  }
+
   Frame(this.uri, this.line, this.column, this.member);
 
   String toString() => '$location in $member';
diff --git a/pkgs/stack_trace/lib/src/trace.dart b/pkgs/stack_trace/lib/src/trace.dart
index a1691ed..f615cd2 100644
--- a/pkgs/stack_trace/lib/src/trace.dart
+++ b/pkgs/stack_trace/lib/src/trace.dart
@@ -10,6 +10,7 @@
 import 'chain.dart';
 import 'frame.dart';
 import 'lazy_trace.dart';
+import 'unparsed_frame.dart';
 import 'utils.dart';
 import 'vm_trace.dart';
 
@@ -115,7 +116,7 @@
     try {
       if (trace.isEmpty) return new Trace(<Frame>[]);
       if (trace.contains(_v8Trace)) return new Trace.parseV8(trace);
-      if (trace.startsWith("\tat ")) return new Trace.parseJSCore(trace);
+      if (trace.contains("\tat ")) return new Trace.parseJSCore(trace);
       if (trace.contains(_firefoxSafariTrace)) {
         return new Trace.parseFirefox(trace);
       }
@@ -262,7 +263,7 @@
 
     var newFrames = [];
     for (var frame in frames.reversed) {
-      if (!predicate(frame)) {
+      if (frame is UnparsedFrame || !predicate(frame)) {
         newFrames.add(frame);
       } else if (newFrames.isEmpty || !predicate(newFrames.last)) {
         newFrames.add(new Frame(
@@ -272,7 +273,7 @@
 
     if (terse) {
       newFrames = newFrames.map((frame) {
-        if (!predicate(frame)) return frame;
+        if (frame is UnparsedFrame || !predicate(frame)) return frame;
         var library = frame.library.replaceAll(_terseRegExp, '');
         return new Frame(Uri.parse(library), null, null, frame.member);
       }).toList();
@@ -290,6 +291,7 @@
 
     // Print out the stack trace nicely formatted.
     return frames.map((frame) {
+      if (frame is UnparsedFrame) return "$frame\n";
       return '${padRight(frame.location, longest)}  ${frame.member}\n';
     }).join();
   }
diff --git a/pkgs/stack_trace/lib/src/unparsed_frame.dart b/pkgs/stack_trace/lib/src/unparsed_frame.dart
new file mode 100644
index 0000000..19d09c6
--- /dev/null
+++ b/pkgs/stack_trace/lib/src/unparsed_frame.dart
@@ -0,0 +1,26 @@
+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library stack_trace.unparsed_frame;
+
+import 'frame.dart';
+
+/// A frame that failed to parse.
+///
+/// The [member] property contains the original frame's contents.
+class UnparsedFrame implements Frame {
+  final Uri uri = new Uri(path: "unparsed");
+  final int line = null;
+  final int column = null;
+  final bool isCore = false;
+  final String library = "unparsed";
+  final String package = null;
+  final String location = "unparsed";
+
+  final String member;
+
+  UnparsedFrame(this.member);
+
+  String toString() => _original;
+}
\ No newline at end of file
diff --git a/pkgs/stack_trace/lib/stack_trace.dart b/pkgs/stack_trace/lib/stack_trace.dart
index ac875a9..6bba635 100644
--- a/pkgs/stack_trace/lib/stack_trace.dart
+++ b/pkgs/stack_trace/lib/stack_trace.dart
@@ -23,6 +23,7 @@
  */
 library stack_trace;
 
-export 'src/trace.dart';
-export 'src/frame.dart';
 export 'src/chain.dart';
+export 'src/frame.dart';
+export 'src/trace.dart';
+export 'src/unparsed_frame.dart';
diff --git a/pkgs/stack_trace/test/frame_test.dart b/pkgs/stack_trace/test/frame_test.dart
index 809822a..1233cbf 100644
--- a/pkgs/stack_trace/test/frame_test.dart
+++ b/pkgs/stack_trace/test/frame_test.dart
@@ -71,14 +71,14 @@
       expect(frame.column, isNull);
     });
 
-    test('throws a FormatException for malformed frames', () {
-      expect(() => new Frame.parseVM(''), throwsFormatException);
-      expect(() => new Frame.parseVM('#1'), throwsFormatException);
-      expect(() => new Frame.parseVM('#1      Foo'), throwsFormatException);
-      expect(() => new Frame.parseVM('#1      (dart:async/future.dart:10:15)'),
-          throwsFormatException);
-      expect(() => new Frame.parseVM('Foo (dart:async/future.dart:10:15)'),
-          throwsFormatException);
+    test('returns an UnparsedFrame for malformed frames', () {
+      expectIsUnparsed((text) => new Frame.parseV8(text), '');
+      expectIsUnparsed((text) => new Frame.parseV8(text), '#1');
+      expectIsUnparsed((text) => new Frame.parseV8(text), '#1      Foo');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          '#1      (dart:async/future.dart:10:15)');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          'Foo (dart:async/future.dart:10:15)');
     });
   });
 
@@ -219,24 +219,22 @@
           equals('<fn>.<fn>.bar'));
     });
 
-    test('throws a FormatException for malformed frames', () {
-      expect(() => new Frame.parseV8(''), throwsFormatException);
-      expect(() => new Frame.parseV8('    at'), throwsFormatException);
-      expect(() => new Frame.parseV8('    at Foo'), throwsFormatException);
-      expect(() => new Frame.parseV8('    at Foo (dart:async/future.dart)'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('    at Foo (dart:async/future.dart:10)'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('    at (dart:async/future.dart:10:15)'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('Foo (dart:async/future.dart:10:15)'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('    at dart:async/future.dart'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('    at dart:async/future.dart:10'),
-          throwsFormatException);
-      expect(() => new Frame.parseV8('dart:async/future.dart:10:15'),
-          throwsFormatException);
+    test('returns an UnparsedFrame for malformed frames', () {
+      expectIsUnparsed((text) => new Frame.parseV8(text), '');
+      expectIsUnparsed((text) => new Frame.parseV8(text), '    at');
+      expectIsUnparsed((text) => new Frame.parseV8(text), '    at Foo');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          '    at Foo (dart:async/future.dart)');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          '    at (dart:async/future.dart:10:15)');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          'Foo (dart:async/future.dart:10:15)');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          '    at dart:async/future.dart');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          '    at dart:async/future.dart:10');
+      expectIsUnparsed((text) => new Frame.parseV8(text),
+          'dart:async/future.dart:10:15');
     });
   });
 
@@ -376,15 +374,15 @@
       expect(frame.member, equals("convertDartClosureToJS.<fn>.<fn>"));
     });
 
-    test('throws a FormatException for malformed frames', () {
-      expect(() => new Frame.parseFirefox(''), throwsFormatException);
-      expect(() => new Frame.parseFirefox('.foo'), throwsFormatException);
-      expect(() => new Frame.parseFirefox('.foo@dart:async/future.dart'),
-          throwsFormatException);
-      expect(() => new Frame.parseFirefox('.foo(@dart:async/future.dart:10'),
-          throwsFormatException);
-      expect(() => new Frame.parseFirefox('@dart:async/future.dart'),
-          throwsFormatException);
+    test('returns an UnparsedFrame for malformed frames', () {
+      expectIsUnparsed((text) => new Frame.parseFirefox(text), '');
+      expectIsUnparsed((text) => new Frame.parseFirefox(text), '.foo');
+      expectIsUnparsed((text) => new Frame.parseFirefox(text),
+          '.foo@dart:async/future.dart');
+      expectIsUnparsed((text) => new Frame.parseFirefox(text),
+          '.foo(@dart:async/future.dart:10');
+      expectIsUnparsed((text) => new Frame.parseFirefox(text),
+          '@dart:async/future.dart');
     });
 
     test('parses a simple stack frame correctly', () {
@@ -470,12 +468,11 @@
       expect(frame.member, equals('Foo.<fn>.bar'));
     });
 
-    test('throws a FormatException for malformed frames', () {
-      expect(() => new Frame.parseFriendly(''), throwsFormatException);
-      expect(() => new Frame.parseFriendly('foo/bar.dart'),
-          throwsFormatException);
-      expect(() => new Frame.parseFriendly('foo/bar.dart 10:11'),
-          throwsFormatException);
+    test('returns an UnparsedFrame for malformed frames', () {
+      expectIsUnparsed((text) => new Frame.parseFriendly(text), '');
+      expectIsUnparsed((text) => new Frame.parseFriendly(text), 'foo/bar.dart');
+      expectIsUnparsed((text) => new Frame.parseFriendly(text),
+          'foo/bar.dart 10:11');
     });
   });
 
@@ -562,3 +559,9 @@
     });
   });
 }
+
+void expectIsUnparsed(Frame constructor(String text), String text) {
+  var frame = constructor(text);
+  expect(frame, new isInstanceOf<UnparsedFrame>());
+  expect(frame.toString(), equals(text));
+}
diff --git a/pkgs/stack_trace/test/trace_test.dart b/pkgs/stack_trace/test/trace_test.dart
index 14e1e2b..1cc32f7 100644
--- a/pkgs/stack_trace/test/trace_test.dart
+++ b/pkgs/stack_trace/test/trace_test.dart
@@ -293,8 +293,9 @@
         '#3      baz (dart:async:15:0)\n'));
   });
 
-  test('.terse folds core frames together bottom-up', () {
-    var trace = new Trace.parse('''
+  group("folding", () {
+    test('.terse folds core frames together bottom-up', () {
+      var trace = new Trace.parse('''
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
 #0 notCore (foo.dart:42:21)
@@ -303,30 +304,30 @@
 #5 alsoNotCore (bar.dart:10:20)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:core       bottom
 foo.dart 42:21  notCore
 dart:async      bottom
 bar.dart 10:20  alsoNotCore
 '''));
-  });
+    });
 
-  test('.terse folds empty async frames', () {
-    var trace = new Trace.parse('''
+    test('.terse folds empty async frames', () {
+      var trace = new Trace.parse('''
 #0 top (dart:async/future.dart:0:2)
 #1 empty.<<anonymous closure>_async_body> (bar.dart)
 #2 bottom (dart:async-patch/future.dart:9:11)
 #3 notCore (foo.dart:42:21)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:async      bottom
 foo.dart 42:21  notCore
 '''));
-  });
+    });
 
-  test('.terse removes the bottom-most async frame', () {
-    var trace = new Trace.parse('''
+    test('.terse removes the bottom-most async frame', () {
+      var trace = new Trace.parse('''
 #0 notCore (foo.dart:42:21)
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
@@ -334,32 +335,28 @@
 #4 bottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 foo.dart 42:21  notCore
 '''));
-  });
+    });
 
-  test(".terse won't make a trace empty", () {
-    var trace = new Trace.parse('''
+    test(".terse won't make a trace empty", () {
+      var trace = new Trace.parse('''
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:core  bottom
 '''));
-  });
+    });
 
-  test(".terse won't panic on an empty trace", () {
-    var trace = new Trace.parse('''
-''');
+    test(".terse won't panic on an empty trace", () {
+      expect(Trace.parse("").terse.toString(), equals(""));
+    });
 
-    expect(trace.terse.toString(), equals('''
-'''));
-  });
-
-  test('.foldFrames folds frames together bottom-up', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames folds frames together bottom-up', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 fooBottom (foo.dart:1:100)
@@ -368,17 +365,17 @@
 #5 fooBottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'));
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'));
+      expect(folded.toString(), equals('''
 foo.dart 42:21                     notFoo
 foo.dart 1:100                     fooBottom
 bar.dart 10:20                     alsoNotFoo
 dart:async-patch/future.dart 9:11  fooBottom
 '''));
-  });
+    });
 
-  test('.foldFrames with terse: true folds core frames as well', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames with terse: true folds core frames as well', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 coreBottom (dart:async/future.dart:0:2)
@@ -387,17 +384,17 @@
 #5 coreBottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
-        terse: true);
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
+          terse: true);
+      expect(folded.toString(), equals('''
 foo.dart 42:21  notFoo
 dart:async      coreBottom
 bar.dart 10:20  alsoNotFoo
 '''));
-  });
+    });
 
-  test('.foldFrames with terse: true shortens folded frames', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames with terse: true shortens folded frames', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 fooBottom (package:foo/bar.dart:0:2)
@@ -406,13 +403,28 @@
 #5 fooBottom (foo/bar.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
-        terse: true);
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
+          terse: true);
+      expect(folded.toString(), equals('''
 foo.dart 42:21  notFoo
 package:foo     fooBottom
 bar.dart 10:20  alsoNotFoo
 foo             fooBottom
 '''));
+    });
+
+    test('.foldFrames will never fold unparsed frames', () {
+      var trace = new Trace.parse(r'''
+.g"cs$#:b";a#>sw{*{ul$"$xqwr`p
+%+j-?uppx<([j@#nu{{>*+$%x-={`{
+!e($b{nj)zs?cgr%!;bmw.+$j+pfj~
+''');
+
+      expect(trace.foldFrames((frame) => true).toString(), equals(r'''
+.g"cs$#:b";a#>sw{*{ul$"$xqwr`p
+%+j-?uppx<([j@#nu{{>*+$%x-={`{
+!e($b{nj)zs?cgr%!;bmw.+$j+pfj~
+'''));
+    });
   });
 }