diff --git a/CMakeLists.txt b/CMakeLists.txt
index d7bdda4fc..6cb1ba73e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -183,9 +183,7 @@ if(BUILD_TESTS)
 endif()
 
 # OpenGLTester library, built by default only if GL tests are enabled
-if(NOT CORRADE_TARGET_EMSCRIPTEN)
-    cmake_dependent_option(WITH_OPENGLTESTER "Build OpenGLTester library" OFF "NOT BUILD_GL_TESTS" ON)
-endif()
+cmake_dependent_option(WITH_OPENGLTESTER "Build OpenGLTester library" OFF "NOT BUILD_GL_TESTS" ON)
 
 # Dynamic linking is meaningless on Emscripten and too inconvenient on Android
 if(CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
@@ -231,7 +229,7 @@ if(CORRADE_TARGET_EMSCRIPTEN)
 endif()
 
 if(WITH_OPENGLTESTER)
-    if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_ANDROID)
+    if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
         set(WITH_WINDOWLESSEGLAPPLICATION ON)
         set(OPENGLTESTER_APPLICATION MagnumWindowlessEglApplication)
     elseif(CORRADE_TARGET_IOS)
diff --git a/doc/changelog.dox b/doc/changelog.dox
index e08a64307..30c37c3c7 100644
--- a/doc/changelog.dox
+++ b/doc/changelog.dox
@@ -58,6 +58,7 @@ See also:
         their WebGL counterparts @webgl_extension{EXT,color_buffer_half_float},
         @webgl_extension{WEBGL,color_buffer_float},
         @webgl_extension{EXT,color_buffer_float}
+-   Ported @ref OpenGLTester to WebGL
 
 @subsubsection changelog-latest-new-platform Platform libraries
 
diff --git a/modules/FindMagnum.cmake b/modules/FindMagnum.cmake
index 97cc64921..632b3a82a 100644
--- a/modules/FindMagnum.cmake
+++ b/modules/FindMagnum.cmake
@@ -337,7 +337,7 @@ foreach(_component ${Magnum_FIND_COMPONENTS})
     elseif(_component STREQUAL DebugTools)
         set(_MAGNUM_${_COMPONENT}_DEPENDENCIES MeshTools Primitives SceneGraph Shaders Shapes)
     elseif(_component STREQUAL OpenGLTester)
-        if(MAGNUM_TARGET_HEADLESS)
+        if(MAGNUM_TARGET_HEADLESS OR CORRADE_TARGET_EMSCRIPTEN OR CORRADE_TARGET_ANDROID)
             set(_MAGNUM_${_COMPONENT}_DEPENDENCIES WindowlessEglApplication)
         elseif(CORRADE_TARGET_IOS)
             set(_MAGNUM_${_COMPONENT}_DEPENDENCIES WindowlessIosApplication)
diff --git a/src/Magnum/OpenGLTester.cpp b/src/Magnum/OpenGLTester.cpp
index 7dc5ccb27..896dfbb69 100644
--- a/src/Magnum/OpenGLTester.cpp
+++ b/src/Magnum/OpenGLTester.cpp
@@ -27,20 +27,23 @@
 
 #include "Magnum/Context.h"
 #include "Magnum/Extensions.h"
+#ifndef MAGNUM_TARGET_WEBGL
 #include "Magnum/DebugOutput.h"
+#endif
 
 namespace Magnum {
 
 OpenGLTester::OpenGLTester(): TestSuite::Tester{TestSuite::Tester::TesterConfiguration{}.setSkippedArgumentPrefixes({"magnum"})}, _windowlessApplication{{arguments().first, arguments().second}} {
     /* Try to create debug context, fallback to normal one if not possible. No
-       such thing on macOS or iOS. */
-    #ifndef CORRADE_TARGET_APPLE
+       such thing on macOS, iOS or WebGL. */
+    #if !defined(CORRADE_TARGET_APPLE) && !defined(MAGNUM_TARGET_WEBGL)
     if(!_windowlessApplication.tryCreateContext(Platform::WindowlessApplication::Configuration{}.setFlags(Platform::WindowlessApplication::Configuration::Flag::Debug)))
         _windowlessApplication.createContext();
     #else
     _windowlessApplication.createContext();
     #endif
 
+    #ifndef MAGNUM_TARGET_WEBGL
     if(Context::current().isExtensionSupported<Extensions::GL::KHR::debug>()) {
         Renderer::enable(Renderer::Feature::DebugOutput);
         Renderer::enable(Renderer::Feature::DebugOutputSynchronous);
@@ -49,10 +52,12 @@ OpenGLTester::OpenGLTester(): TestSuite::Tester{TestSuite::Tester::TesterConfigu
         /* Disable "Buffer detailed info" message on NV (too spammy) */
         DebugOutput::setEnabled(DebugOutput::Source::Api, DebugOutput::Type::Other, {131185}, false);
     }
+    #endif
 }
 
 OpenGLTester::~OpenGLTester() = default;
 
+#ifndef MAGNUM_TARGET_WEBGL
 void OpenGLTester::gpuTimeBenchmarkBegin() {
     setBenchmarkName("GPU time");
 
@@ -66,5 +71,6 @@ std::uint64_t OpenGLTester::gpuTimeBenchmarkEnd() {
     _gpuTimeQuery.end();
     return _gpuTimeQuery.result<UnsignedLong>();
 }
+#endif
 
 }
diff --git a/src/Magnum/OpenGLTester.h b/src/Magnum/OpenGLTester.h
index d2aa3caf8..297b47414 100644
--- a/src/Magnum/OpenGLTester.h
+++ b/src/Magnum/OpenGLTester.h
@@ -32,9 +32,8 @@
 #include <Corrade/TestSuite/Tester.h>
 
 #include "Magnum/Renderer.h"
-#include "Magnum/TimeQuery.h"
 
-#if defined(MAGNUM_TARGET_HEADLESS) || defined(CORRADE_TARGET_ANDROID)
+#if defined(MAGNUM_TARGET_HEADLESS) || defined(CORRADE_TARGET_EMSCRIPTEN) || defined(CORRADE_TARGET_ANDROID)
 #include "Magnum/Platform/WindowlessEglApplication.h"
 #elif defined(CORRADE_TARGET_IOS)
 #include "Magnum/Platform/WindowlessIosApplication.h"
@@ -56,6 +55,10 @@
 #error cannot run OpenGL tests on this platform
 #endif
 
+#ifndef MAGNUM_TARGET_WEBGL
+#include "Magnum/TimeQuery.h"
+#endif
+
 namespace Magnum {
 
 /**
@@ -65,15 +68,14 @@ Extends @ref Corrade::TestSuite::Tester with features for OpenGL testing and
 benchmarking. Be sure to read its documentation first to have an overview of
 the base features.
 
-This class is available only on platforms with corresponding
-`Platform::Windowless*Application` implementation. That currently means all
-platforms except @ref CORRADE_TARGET_EMSCRIPTEN "Emscripten". It is built into
-a separate static library and only if `WITH_OPENGLTESTER` is enabled when
-building Magnum. To use it with CMake, you need to request the `OpenGLTester`
-component of the `Magnum` package. Derive your test class from this class
-instead of @ref Corrade::TestSuite::Tester and either link to
-`Magnum::OpenGLTester` target or add it to the `LIBRARIES` section of the
-@ref corrade-cmake-add-test "corrade_add_test()" macro:
+This class is available on platforms with corresponding
+`Platform::Windowless*Application` implementation, which currently means all
+platforms. It is built into a separate static library and only if
+`WITH_OPENGLTESTER` is enabled when building Magnum. To use it with CMake, you
+need to request the `OpenGLTester` component of the `Magnum` package. Derive
+your test class from this class instead of @ref Corrade::TestSuite::Tester and
+either link to `Magnum::OpenGLTester` target or add it to the `LIBRARIES`
+section of the @ref corrade-cmake-add-test "corrade_add_test()" macro:
 
 @code{.cmake}
 find_package(Magnum REQUIRED OpenGLTester)
@@ -91,7 +93,8 @@ drivers. In addition, on desktop, unless Magnum is built with
 `MAGNUM_TARGET_HEADLESS`, OpenGL context creation requires a graphical desktop
 to be running. On embedded systems (and @ref CORRADE_TARGET_IOS "iOS",
 @ref CORRADE_TARGET_ANDROID "Android" in particular) running the tests has no
-special requirements.
+special requirements. On Emscripten the tests have to be running in a browser,
+as Node.js environment doesn't provide a WebGL context.
 
 On virtualized systems and systems without a GPU (e.g. CI servers) it's
 possible to link against e.g. Mesa softpipe or
@@ -126,9 +129,11 @@ all platforms and not all GL errors are fatal.
 
 This class adds @ref BenchmarkType::GpuTime to the benchmark type enum,
 allowing you to measure time spent on GPU as opposed to CPU or wall clock time.
+@requires_gles GPU time benchmarking is not available on WebGL.
 */
 class OpenGLTester: public TestSuite::Tester {
     public:
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Benchmark type
          *
@@ -167,9 +172,11 @@ class OpenGLTester: public TestSuite::Tester {
              * thus may cause pipeline bubble. Increase number of iterations
              * passed to @ref CORRADE_BENCHMARK() to amortize the measurement
              * error.
+             * @requires_gles GPU time benchmarking is not available on WebGL.
              */
             GpuTime = 32
         };
+        #endif
 
         /**
          * @brief Constructor
@@ -180,11 +187,13 @@ class OpenGLTester: public TestSuite::Tester {
 
         ~OpenGLTester();
 
+        #ifndef MAGNUM_TARGET_WEBGL
         /**
          * @brief Add benchmarks
          *
          * Extends @ref Corrade::TestSuite::Tester::addBenchmarks(std::initializer_list<void(Derived::*)()>, std::size_t, BenchmarkType) with support
          * for GPU benchmark types.
+         * @requires_gles GPU time benchmarking is not available on WebGL.
          */
         template<class Derived> void addBenchmarks(std::initializer_list<void(Derived::*)()> benchmarks, std::size_t batchCount, BenchmarkType benchmarkType = BenchmarkType::Default) {
             if(benchmarkType == BenchmarkType::GpuTime)
@@ -198,6 +207,7 @@ class OpenGLTester: public TestSuite::Tester {
          *
          * Extends @ref Corrade::TestSuite::Tester::addBenchmarks(std::initializer_list<void(Derived::*)()>, std::size_t, void(Derived::*)(), void(Derived::*)(), BenchmarkType) with support
          * for GPU benchmark types.
+         * @requires_gles GPU time benchmarking is not available on WebGL.
          */
         template<class Derived> void addBenchmarks(std::initializer_list<void(Derived::*)()> benchmarks, std::size_t batchCount, void(Derived::*setup)(), void(Derived::*teardown)(), BenchmarkType benchmarkType = BenchmarkType::Default) {
             if(benchmarkType == BenchmarkType::GpuTime)
@@ -211,6 +221,7 @@ class OpenGLTester: public TestSuite::Tester {
          *
          * Extends @ref Corrade::TestSuite::Tester::addInstancedBenchmarks(std::initializer_list<void(Derived::*)()>, std::size_t, std::size_t, BenchmarkType) with support for GPU
          * benchmark types.
+         * @requires_gles GPU time benchmarking is not available on WebGL.
          */
         template<class Derived> void addInstancedBenchmarks(std::initializer_list<void(Derived::*)()> benchmarks, std::size_t batchCount, std::size_t instanceCount, BenchmarkType benchmarkType = BenchmarkType::Default) {
             if(benchmarkType == BenchmarkType::GpuTime)
@@ -224,6 +235,7 @@ class OpenGLTester: public TestSuite::Tester {
          *
          * Extends @ref Corrade::TestSuite::Tester::addInstancedBenchmarks(std::initializer_list<void(Derived::*)()>, std::size_t, std::size_t, void(Derived::*)(), void(Derived::*)(), BenchmarkType)
          * with support for GPU benchmark types.
+         * @requires_gles GPU time benchmarking is not available on WebGL.
          */
         template<class Derived> void addInstancedBenchmarks(std::initializer_list<void(Derived::*)()> benchmarks, std::size_t batchCount, std::size_t instanceCount, void(Derived::*setup)(), void(Derived::*teardown)(), BenchmarkType benchmarkType = BenchmarkType::Default) {
             if(benchmarkType == BenchmarkType::GpuTime)
@@ -231,10 +243,13 @@ class OpenGLTester: public TestSuite::Tester {
             else
                 Tester::addInstancedBenchmarks(benchmarks, batchCount, instanceCount, setup, teardown, Tester::BenchmarkType(Int(benchmarkType)));
         }
+        #endif
 
     private:
+        #ifndef MAGNUM_TARGET_WEBGL
         void gpuTimeBenchmarkBegin();
         std::uint64_t gpuTimeBenchmarkEnd();
+        #endif
 
         struct WindowlessApplication: Platform::WindowlessApplication {
             explicit WindowlessApplication(const Arguments& arguments): Platform::WindowlessApplication{arguments, NoCreate} {}
@@ -245,7 +260,9 @@ class OpenGLTester: public TestSuite::Tester {
 
         } _windowlessApplication;
 
+        #ifndef MAGNUM_TARGET_WEBGL
         TimeQuery _gpuTimeQuery{NoCreate};
+        #endif
 };
 
 /** @hideinitializer