@@ -369,6 +369,8 @@ def bin_path(cls):
     @classmethod
     def isAvailable(cls):
         """Return whether a MovieWriter subclass is actually available."""
+        if sys.platform == 'emscripten':
+            return False
         return shutil.which(cls.bin_path()) is not None
 
 
 
@@ -1297,7 +1297,7 @@ def find_tex_file(filename):
 
     try:
         lk = _LuatexKpsewhich()
-    except FileNotFoundError:
+    except (FileNotFoundError, OSError):
         lk = None  # Fallback to directly calling kpsewhich, as below.
 
     if lk:
@@ -1320,7 +1320,7 @@ def find_tex_file(filename):
             path = cbook._check_and_log_subprocess(
                 ['kpsewhich', '-mktex=pk', filename], _log, **kwargs,
             ).rstrip('\n')
-        except (FileNotFoundError, RuntimeError):
+        except (FileNotFoundError, OSError, RuntimeError):
             path = None
 
     if path:
 
@@ -87,9 +87,14 @@ def subprocess_run_for_testing(command, env=None, timeout=60, stdout=None,
 
     Raises
     ------
+    pytest.skip
+        If running on emscripten, which does not support subprocesses.
     pytest.xfail
         If platform is Cygwin and subprocess reports a fork() failure.
     """
+    if sys.platform == 'emscripten':
+        import pytest
+        pytest.skip('emscripten does not support subprocesses')
     if capture_output:
         stdout = stderr = subprocess.PIPE
     # Add CREATE_NO_WINDOW flag on Windows to prevent console window overhead
@@ -208,7 +213,7 @@ def _has_tex_package(package):
     try:
         mpl.dviread.find_tex_file(f"{package}.sty")
         return True
-    except FileNotFoundError:
+    except (FileNotFoundError, OSError):
         return False
 
 
 
@@ -139,6 +139,8 @@ def copy_baseline(self, baseline, extension):
             try:
                 if 'microsoft' in uname().release.lower():
                     raise OSError  # On WSL, symlink breaks silently
+                if sys.platform == 'emscripten':
+                    raise OSError
                 os.symlink(orig_expected_path, expected_fname)
             except OSError:  # On Windows, symlink *may* be unavailable.
                 shutil.copyfile(orig_expected_path, expected_fname)
 
@@ -271,6 +271,8 @@ def test_no_length_frames(anim):
     anim.save('unused.null', writer=NullMovieWriter())
 
 
+@pytest.mark.skipif(sys.platform == 'emscripten',
+                    reason='emscripten does not support subprocesses')
 def test_movie_writer_registry():
     assert len(animation.writers._registered) > 0
     mpl.rcParams['animation.ffmpeg_path'] = "not_available_ever_xxxx"
@@ -522,6 +524,8 @@ def test_disable_cache_warning(anim):
 def test_movie_writer_invalid_path(anim):
     if sys.platform == "win32":
         match_str = r"\[WinError 3] .*\\\\foo\\\\bar\\\\aardvark'"
+    elif sys.platform == "emscripten":
+        match_str = r"\[Errno 44] .*'/foo"
     else:
         match_str = r"\[Errno 2] .*'/foo"
     with pytest.raises(FileNotFoundError, match=match_str):
 
@@ -1,6 +1,7 @@
 import json
 from pathlib import Path
 import shutil
+import sys
 
 from matplotlib import cbook, dviread as dr
 from matplotlib.testing import subprocess_run_for_testing, _has_tex_package
@@ -61,7 +62,7 @@ def test_PsfontsMap(monkeypatch):
         fontmap[b'%']
 
 
-@pytest.mark.skipif(shutil.which("kpsewhich") is None,
+@pytest.mark.skipif(sys.platform == "emscripten" or shutil.which("kpsewhich") is None,
                     reason="kpsewhich is not available")
 @pytest.mark.parametrize("engine", ["pdflatex", "xelatex", "lualatex"])
 def test_dviread(tmp_path, engine, monkeypatch):
 
@@ -3,6 +3,7 @@
 import io
 import pickle
 import platform
+import sys
 from threading import Timer
 from types import SimpleNamespace
 import warnings
@@ -1629,6 +1630,8 @@ def test_add_axes_kwargs():
     plt.close()
 
 
+@pytest.mark.skipif(sys.platform == 'emscripten',
+                    reason='emscripten does not support threads')
 def test_ginput(recwarn):  # recwarn undoes warn filters at exit.
     warnings.filterwarnings("ignore", "cannot show the figure")
     fig, ax = plt.subplots()
@@ -1651,6 +1654,8 @@ def multi_presses():
     np.testing.assert_allclose(fig.ginput(3), [(.3, .4), (.5, .6)])
 
 
+@pytest.mark.skipif(sys.platform == 'emscripten',
+                    reason='emscripten does not support threads')
 def test_waitforbuttonpress(recwarn):  # recwarn undoes warn filters at exit.
     warnings.filterwarnings("ignore", "cannot show the figure")
     fig = plt.figure()
 
@@ -229,6 +229,8 @@ def _model_handler(_):
     plt.close()
 
 
+@pytest.mark.skipif(sys.platform == 'emscripten',
+                    reason='emscripten does not support subprocesses')
 @pytest.mark.skipif(not hasattr(os, "register_at_fork"),
                     reason="Cannot register at_fork handlers")
 def test_fork():
 
@@ -258,10 +258,6 @@ def _run_checked_subprocess(cls, command, tex, *, cwd=None):
             report = subprocess.check_output(
                 command, cwd=cwd if cwd is not None else cls._cache_dir,
                 stderr=subprocess.STDOUT)
-        except FileNotFoundError as exc:
-            raise RuntimeError(
-                f'Failed to process string with tex because {command[0]} '
-                'could not be found') from exc
         except subprocess.CalledProcessError as exc:
             raise RuntimeError(
                 '{prog} was not able to process the following string:\n'
@@ -274,6 +270,10 @@ def _run_checked_subprocess(cls, command, tex, *, cwd=None):
                     tex=tex.encode('unicode_escape'),
                     exc=exc.output.decode('utf-8', 'backslashreplace'))
                 ) from None
+        except (FileNotFoundError, OSError) as exc:
+            raise RuntimeError(
+                f'Failed to process string with tex because {command[0]} '
+                'could not be found') from exc
         _log.debug(report)
         return report