diff --git a/.appveyor.yml b/.appveyor.yml
deleted file mode 100644
index 7229a25..0000000
--- a/.appveyor.yml
+++ /dev/null
@@ -1,37 +0,0 @@
-# Build matrix / environment variables are explained on:
-# https://www.appveyor.com/docs/appveyor-yml/
-# This file can be validated on: https://ci.appveyor.com/tools/validate-yaml
-
-version: "{build}"
-
-environment:
-  matrix:
-    # AppVeyor currently has no custom job name feature.
-    # http://help.appveyor.com/discussions/questions/1623-can-i-provide-a-friendly-name-for-jobs
-    - JOB: Visual Studio 2019
-      APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2019
-      CMAKE_GENERATOR: Visual Studio 16 2019
-
-platform:
-  - x86
-  - x64
-
-configuration:
-  - RelWithDebInfo
-  - Debug
-
-build_script:
-  - git submodule update --init --recursive
-  - mkdir build
-  - cd build
-  - if "%platform%"=="x86" (set CMAKE_GENERATOR_PLATFORM="Win32")
-      else (set CMAKE_GENERATOR_PLATFORM="%platform%")
-  - cmake --version
-  - cmake .. -G "%CMAKE_GENERATOR%" -A "%CMAKE_GENERATOR_PLATFORM%"
-      -DCMAKE_CONFIGURATION_TYPES="%CONFIGURATION%" -DSNAPPY_REQUIRE_AVX2=ON
-  - cmake --build . --config %CONFIGURATION%
-  - cd ..
-
-test_script:
-  - build\%CONFIGURATION%\snappy_unittest
-  - build\%CONFIGURATION%\snappy_benchmark
diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
new file mode 100644
index 0000000..fc2ad10
--- /dev/null
+++ b/.github/workflows/build.yml
@@ -0,0 +1,135 @@
+# Copyright 2021 Google Inc. All Rights Reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+name: ci
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build-and-test:
+    name:  >-
+      CI
+      ${{ matrix.os }}
+      ${{ matrix.cpu_level }}
+      ${{ matrix.compiler }}
+      ${{ matrix.optimized && 'release' || 'debug' }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        compiler: [clang, gcc, msvc]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+        cpu_level: [baseline, avx, avx2]
+        optimized: [true, false]
+        exclude:
+        # MSVC only works on Windows.
+        - os: ubuntu-latest
+          compiler: msvc
+        - os: macos-latest
+          compiler: msvc
+        # GitHub servers seem to run on pre-Haswell CPUs. Attempting to use AVX2
+        # results in crashes.
+        - os: macos-latest
+          cpu_level: avx2
+        # Not testing with GCC on macOS.
+        - os: macos-latest
+          compiler: gcc
+        # Only testing with MSVC on Windows.
+        - os: windows-latest
+          compiler: clang
+        - os: windows-latest
+          compiler: gcc
+        include:
+        - compiler: clang
+          CC: clang
+          CXX: clang++
+        - compiler: gcc
+          CC: gcc
+          CXX: g++
+        - compiler: msvc
+          CC:
+          CXX:
+
+    env:
+      CMAKE_BUILD_DIR: ${{ github.workspace }}/build
+      CMAKE_BUILD_TYPE: ${{ matrix.optimized && 'RelWithDebInfo' || 'Debug' }}
+      CC: ${{ matrix.CC }}
+      CXX: ${{ matrix.CXX }}
+      SNAPPY_REQUIRE_AVX: ${{ matrix.cpu_level == 'baseline' && '0' || '1' }}
+      SNAPPY_REQUIRE_AVX2: ${{ matrix.cpu_level == 'avx2' && '1' || '0' }}
+      SNAPPY_FUZZING_BUILD: >-
+        ${{ (startsWith(matrix.os, 'ubuntu') && matrix.compiler == 'clang' &&
+        !matrix.optimized) && '1' || '0' }}
+      BINARY_SUFFIX: ${{ startsWith(matrix.os, 'windows') && '.exe' || '' }}
+      BINARY_PATH: >-
+        ${{ format(
+        startsWith(matrix.os, 'windows') && '{0}\build\{1}\' || '{0}/build/',
+        github.workspace,
+        matrix.optimized && 'RelWithDebInfo' || 'Debug') }}
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        submodules: true
+
+    - name: Generate build config
+      run: >-
+        cmake -S "${{ github.workspace }}" -B "${{ env.CMAKE_BUILD_DIR }}"
+        -DCMAKE_BUILD_TYPE=${{ env.CMAKE_BUILD_TYPE }}
+        -DCMAKE_INSTALL_PREFIX=${{ runner.temp }}/install_test/
+        -DSNAPPY_FUZZING_BUILD=${{ env.SNAPPY_FUZZING_BUILD }}
+        -DSNAPPY_REQUIRE_AVX=${{ env.SNAPPY_REQUIRE_AVX }}
+        -DSNAPPY_REQUIRE_AVX2=${{ env.SNAPPY_REQUIRE_AVX2 }}
+
+    - name: Build
+      run: >-
+        cmake --build "${{ env.CMAKE_BUILD_DIR }}"
+        --config "${{ env.CMAKE_BUILD_TYPE }}"
+
+    - name: Run C++ API Tests
+      run: ${{ env.BINARY_PATH }}snappy_unittest${{ env.BINARY_SUFFIX }}
+
+    - name: Run Compression Fuzzer
+      if: ${{ env.SNAPPY_FUZZING_BUILD == '1' }}
+      run: >-
+        ${{ env.BINARY_PATH }}snappy_compress_fuzzer${{ env.BINARY_SUFFIX }}
+        -runs=1000 -close_fd_mask=3
+
+    - name: Run Decompression Fuzzer
+      if: ${{ env.SNAPPY_FUZZING_BUILD == '1' }}
+      run: >-
+        ${{ env.BINARY_PATH }}snappy_uncompress_fuzzer${{ env.BINARY_SUFFIX }}
+        -runs=1000 -close_fd_mask=3
+
+    - name: Run Benchmarks
+      run: ${{ env.BINARY_PATH }}snappy_benchmark${{ env.BINARY_SUFFIX }}
+
+    - name: Test CMake installation
+      run: cmake --build "${{ env.CMAKE_BUILD_DIR }}" --target install
diff --git a/.travis.yml b/.travis.yml
deleted file mode 100644
index 33b9072..0000000
--- a/.travis.yml
+++ /dev/null
@@ -1,109 +0,0 @@
-# Build matrix / environment variables are explained on:
-# http://about.travis-ci.org/docs/user/build-configuration/
-# This file can be validated on: http://lint.travis-ci.org/
-
-language: cpp
-dist: bionic
-osx_image: xcode12.5
-
-compiler:
-- gcc
-- clang
-os:
-- linux
-- osx
-
-env:
-  jobs:
-  - BUILD_TYPE: Debug
-    CPU_LEVEL: BASELINE
-  - BUILD_TYPE: Debug
-    CPU_LEVEL: AVX
-  - BUILD_TYPE: Debug
-    CPU_LEVEL: AVX2
-  - BUILD_TYPE: RelWithDebInfo
-    CPU_LEVEL: BASELINE
-  - BUILD_TYPE: RelWithDebInfo
-    CPU_LEVEL: AVX
-  - BUILD_TYPE: RelWithDebInfo
-    CPU_LEVEL: AVX2
-
-jobs:
-  exclude:
-  # Travis OSX servers seem to run on pre-Haswell CPUs. Attempting to use AVX2
-  # results in crashes.
-  - env: BUILD_TYPE=Debug CPU_LEVEL=AVX2
-    os: osx
-  - env: BUILD_TYPE=RelWithDebInfo CPU_LEVEL=AVX2
-    os: osx
-  allow_failures:
-  # Homebrew's GCC is currently broken on XCode 11.
-  - compiler: gcc
-    os: osx
-
-addons:
-  apt:
-    sources:
-    - sourceline: 'deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-12 main'
-      key_url: 'https://apt.llvm.org/llvm-snapshot.gpg.key'
-    - sourceline: 'ppa:ubuntu-toolchain-r/test'
-    packages:
-    - clang-12
-    - cmake
-    - gcc-11
-    - g++-11
-    - ninja-build
-  homebrew:
-    packages:
-    - cmake
-    - gcc@11
-    - llvm@12
-    - ninja
-    update: true
-
-install:
-# The following Homebrew packages aren't linked by default, and need to be
-# prepended to the path explicitly.
-- if [ "$TRAVIS_OS_NAME" = "osx" ]; then
-    export PATH="$(brew --prefix llvm)/bin:$PATH";
-  fi
-# Fuzzing is only supported on Clang. Perform fuzzing on Debug builds.
-# LibFuzzer doesn't ship with CommandLineTools on osx.
-- if [ "$CXX" = "clang++" ] && [ "$BUILD_TYPE" = "Debug" ] && [ "$TRAVIS_OS_NAME" != "osx" ]; then
-    export FUZZING=1;
-  else
-    export FUZZING=0;
-  fi
-# /usr/bin/gcc points to an older compiler on both Linux and macOS.
-- if [ "$CXX" = "g++" ]; then export CXX="g++-11" CC="gcc-11"; fi
-# /usr/bin/clang points to an older compiler on both Linux and macOS.
-#
-# Homebrew's llvm package doesn't ship a versioned clang++ binary, so the values
-# below don't work on macOS. Fortunately, the path change above makes the
-# default values (clang and clang++) resolve to the correct compiler on macOS.
-- if [ "$TRAVIS_OS_NAME" = "linux" ]; then
-    if [ "$CXX" = "clang++" ]; then export CXX="clang++-12" CC="clang-12"; fi;
-  fi
-- echo ${CC}
-- echo ${CXX}
-- ${CXX} --version
-- cmake --version
-
-before_script:
-- mkdir -p build && cd build
-- cmake .. -G Ninja -DCMAKE_BUILD_TYPE=$BUILD_TYPE
-    -DSNAPPY_REQUIRE_${CPU_LEVEL}=ON -DSNAPPY_FUZZING_BUILD=${FUZZING}
-    -DCMAKE_INSTALL_PREFIX=$HOME/.local
-- cmake --build .
-- cd ..
-
-script:
-- build/snappy_unittest
-- build/snappy_benchmark
-- if [ -f build/snappy_compress_fuzzer ]; then
-    build/snappy_compress_fuzzer -runs=1000 -close_fd_mask=3;
-  fi
-- if [ -f build/snappy_uncompress_fuzzer ]; then
-    build/snappy_uncompress_fuzzer -runs=1000 -close_fd_mask=3;
-  fi
-- cd build && cmake --build . --target install
diff --git a/README.md b/README.md
index 7917d1b..c6f7a07 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,6 @@
 Snappy, a fast compressor/decompressor.
 
-[![Build Status](https://travis-ci.org/google/snappy.svg?branch=master)](https://travis-ci.org/google/snappy)
-[![Build status](https://ci.appveyor.com/api/projects/status/t9nubcqkwo8rw8yn/branch/master?svg=true)](https://ci.appveyor.com/project/pwnall/leveldb)
+[![Build Status](https://github.com/google/snappy/actions/workflows/build.yml/badge.svg)](https://github.com/google/snappy/actions/workflows/build.yml)
 
 Introduction
 ============