diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..b46ec1e
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,154 @@
+name: CI
+on: [push, pull_request]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      max-parallel: 20
+      matrix:
+        test_lang: [c]
+        target:
+          - os: linux
+            cpu: amd64
+          - os: linux
+            cpu: i386
+          - os: macos
+            cpu: amd64
+          - os: windows
+            cpu: amd64
+          - os: windows
+            cpu: i386
+        include:
+          - target:
+              os: linux
+            builder: ubuntu-18.04
+          - target:
+              os: macos
+            builder: macos-10.15
+          - target:
+              os: windows
+            builder: windows-2019
+
+    name: '${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ matrix.test_lang }}'
+    runs-on: ${{ matrix.builder }}
+    steps:
+      - name: Checkout nim-ethash
+        uses: actions/checkout@v2
+        with:
+          path: nim-ethash
+          submodules: false
+
+      - name: Install build dependencies (Linux i386)
+        if: runner.os == 'Linux' && matrix.target.cpu == 'i386'
+        run: |
+          sudo dpkg --add-architecture i386
+          sudo apt-fast update -qq
+          sudo DEBIAN_FRONTEND='noninteractive' apt-fast install \
+            --no-install-recommends -yq gcc-multilib g++-multilib \
+            libssl-dev:i386
+          mkdir -p external/bin
+          cat << EOF > external/bin/gcc
+          #!/bin/bash
+          exec $(which gcc) -m32 "\$@"
+          EOF
+          cat << EOF > external/bin/g++
+          #!/bin/bash
+          exec $(which g++) -m32 "\$@"
+          EOF
+          chmod 755 external/bin/gcc external/bin/g++
+          echo '${{ github.workspace }}/external/bin' >> $GITHUB_PATH
+
+      - name: Restore MinGW-W64 (Windows) from cache
+        if: runner.os == 'Windows'
+        id: windows-mingw-cache
+        uses: actions/cache@v2
+        with:
+          path: external/mingw-${{ matrix.target.cpu }}
+          key: 'mingw-${{ matrix.target.cpu }}'
+
+      - name: Restore Nim DLLs dependencies (Windows) from cache
+        if: runner.os == 'Windows'
+        id: windows-dlls-cache
+        uses: actions/cache@v2
+        with:
+          path: external/dlls-${{ matrix.target.cpu }}
+          key: 'dlls-${{ matrix.target.cpu }}'
+
+      - name: Install MinGW64 dependency (Windows)
+        if: >
+          steps.windows-mingw-cache.outputs.cache-hit != 'true' &&
+          runner.os == 'Windows'
+        shell: bash
+        run: |
+          mkdir -p external
+          MINGW_BASE="https://github.com/brechtsanders/winlibs_mingw/releases/download/11.2.0-12.0.1-9.0.0-r1"
+          if [[ '${{ matrix.target.cpu }}' == 'amd64' ]]; then
+            MINGW_URL="$MINGW_BASE/winlibs-x86_64-posix-seh-gcc-11.2.0-mingw-w64-9.0.0-r1.7z"
+            ARCH=64
+          else
+            MINGW_URL="$MINGW_BASE/winlibs-i686-posix-dwarf-gcc-11.2.0-mingw-w64-9.0.0-r1.7z"
+            ARCH=32
+          fi
+          curl -L "$MINGW_URL" -o "external/mingw-${{ matrix.target.cpu }}.7z"
+          7z x -y "external/mingw-${{ matrix.target.cpu }}.7z" -oexternal/
+          mv external/mingw$ARCH external/mingw-${{ matrix.target.cpu }}
+
+      - name: Install DLLs dependencies (Windows)
+        if: >
+          steps.windows-dlls-cache.outputs.cache-hit != 'true' &&
+          runner.os == 'Windows'
+        shell: bash
+        run: |
+          mkdir -p external
+          curl -L "https://nim-lang.org/download/windeps.zip" -o external/windeps.zip
+          7z x -y external/windeps.zip -oexternal/dlls-${{ matrix.target.cpu }}
+
+      - name: Path to cached dependencies (Windows)
+        if: >
+          runner.os == 'Windows'
+        shell: bash
+        run: |
+          echo '${{ github.workspace }}'"/external/mingw-${{ matrix.target.cpu }}/bin" >> $GITHUB_PATH
+          echo '${{ github.workspace }}'"/external/dlls-${{ matrix.target.cpu }}" >> $GITHUB_PATH
+
+      - name: Get latest nimbus-build-system commit hash
+        id: versions
+        shell: bash
+        run: |
+          getHash() {
+            git ls-remote "https://github.com/$1" "${2:-HEAD}" | cut -f 1
+          }
+          nbsHash=$(getHash status-im/nimbus-build-system)
+          echo "::set-output name=nimbus_build_system::$nbsHash"
+
+      - name: Restore prebuilt Nim from cache
+        id: nim-cache
+        uses: actions/cache@v2
+        with:
+          path: NimBinaries
+          key: '${{ matrix.test_lang }}-${{ matrix.target.os }}-${{ matrix.target.cpu }}-${{ steps.versions.outputs.nimbus_build_system }}'
+
+      - name: Build Nim and associated tools
+        shell: bash
+        run: |
+          curl -O -L -s -S https://raw.githubusercontent.com/status-im/nimbus-build-system/master/scripts/build_nim.sh
+          if [[ '${{ matrix.target.cpu }}' == 'amd64' ]]; then
+            PLATFORM=x64
+          else
+            PLATFORM=x86
+          fi
+          if [[ '${{ matrix.target.os }}' == 'windows' ]]; then
+            MAKE_CMD="mingw32-make"
+          else
+            MAKE_CMD="make"
+          fi
+          env MAKE="$MAKE_CMD -j2" ARCH_OVERRIDE=$PLATFORM CC=gcc bash build_nim.sh nim csources dist/nimble NimBinaries
+          echo '${{ github.workspace }}/nim/bin' >> $GITHUB_PATH
+
+      - name: Run nim-ethash tests
+        shell: bash
+        working-directory: nim-ethash
+        run: |
+          nimble install -y --depsOnly
+          env TEST_LANG="${{ matrix.test_lang }}" nimble test
diff --git a/README.md b/README.md
index e6975f8..0fa1e7c 100644
--- a/README.md
+++ b/README.md
@@ -1,10 +1,9 @@
 # ethash
 
-[![Build Status (Travis)](https://img.shields.io/travis/status-im/nim-ethash/master.svg?label=Linux%20/%20macOS "Linux/macOS build status (Travis)")](https://travis-ci.org/status-im/nim-ethash)
-[![Build status](https://ci.appveyor.com/api/projects/status/am2wc94jm2qo7il3/branch/master?svg=true)](https://ci.appveyor.com/project/nimbus/nim-ethash-ia55s/branch/master)
 [![License: Apache](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://opensource.org/licenses/Apache-2.0)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
 ![Stability: experimental](https://img.shields.io/badge/stability-experimental-orange.svg)
+![Github action](https://github.com/status-im/nim-ethash/workflows/CI/badge.svg)
 
 # Introduction
 A pure-Nim implementation of Ethash, the Ethereum proof of work