diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1bca569e4..1a1a119a5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -88,4 +88,29 @@ jobs:
       - name: Tests with no features
         run: cargo test --verbose --no-default-features
       - name: Tests with all features
-        run: cargo test --verbose --all-features
\ No newline at end of file
+        run: cargo test --verbose --all-features
+
+  coverage:
+    if: github.event_name != 'merge_group'
+    needs: [tests, check]
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: mozilla-actions/sccache-action@v0.0.3
+      - uses: dtolnay/rust-toolchain@nightly
+        with:
+          components: llvm-tools-preview
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
+      - name: Run tests with coverage instrumentation
+        run: |
+            cargo llvm-cov clean --workspace
+            cargo llvm-cov --doctests
+      - name: Generate coverage report
+        run: cargo llvm-cov report --codecov --output-path coverage.json
+      - name: Upload coverage to codecov.io
+        uses: codecov/codecov-action@v3
+        with:
+          files: coverage.json
+          name: ubuntu
+          token: ${{ secrets.CODECOV_TOKEN }}
\ No newline at end of file
diff --git a/.github/workflows/coverage.yml b/.github/workflows/coverage.yml
index 37cf165bb..4a946ef56 100644
--- a/.github/workflows/coverage.yml
+++ b/.github/workflows/coverage.yml
@@ -4,6 +4,7 @@ on:
   schedule:
     # 04:00 daily
     - cron: '0 4 * * *'
+  workflow_dispatch: {}
 
 jobs:
   check-coverage:
@@ -12,12 +13,12 @@ jobs:
       msg: ${{ steps.make_msg.outputs.msg }}
     steps:
       - uses: actions/checkout@v4
-      - name: Install stable toolchain
-        uses: dtolnay/rust-toolchain@stable
-      - name: Install llvm
-        uses: KyleMayes/install-llvm-action@v1
+      - name: Install rust toolchain
+        uses: dtolnay/rust-toolchain@nightly
         with:
-          version: "16.0" # should match version used by rustc
+          components: llvm-tools-preview
+      - name: Install cargo-llvm-cov
+        uses: taiki-e/install-action@cargo-llvm-cov
       - name: Download previous summary
         uses: dawidd6/action-download-artifact@v2
         with:
@@ -26,19 +27,13 @@ jobs:
           name: coverage-summary
       - name: Rename file
         run: mv coverage-summary.txt coverage-summary-prev.txt
+      - name: Run tests with coverage instrumentation
+        run: |
+            cargo llvm-cov clean --workspace
+            cargo llvm-cov --doctests
       - name: Generate coverage report and summary
-        env:
-          RUSTFLAGS: "-C instrument-coverage"
         run: |
-          TGT=`cargo test --tests 2>&1 | grep Running | awk -F'[()]' '{print $2}'`
-          llvm-profdata merge -sparse default_*.profraw -o hugr.profdata
-          llvm-cov show --format=html --ignore-filename-regex='/.cargo/registry' --instr-profile=hugr.profdata --output-dir coverage --object ${TGT}
-          llvm-cov report --ignore-filename-regex='/.cargo/registry' --instr-profile=hugr.profdata --object ${TGT} | grep TOTAL | awk '{print $10}' | tr -dc '[:digit:].' > coverage-summary.txt
-      - name: Upload full report
-        uses: actions/upload-artifact@v3
-        with:
-          name: coverage
-          path: coverage/
+          cargo llvm-cov report --summary-only | grep TOTAL | awk '{print $10}' | tr -dc '[:digit:].' > coverage-summary.txt
       - name: Upload summary
         uses: actions/upload-artifact@v3
         with:
@@ -48,11 +43,12 @@ jobs:
         id: make_msg
         run: |
           change="`cat coverage-summary-prev.txt`% --> `cat coverage-summary.txt`%"
+          codecov="https://codecov.io/gh/${{ github.repository }}?search=&trend=7%20days"
           if (( $(echo "`cat coverage-summary-prev.txt` < `cat coverage-summary.txt` + 0.04" | bc -l) ))
           then
-            echo "msg=Coverage check for hugr shows no regression (${change}). ✅ ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}" >> "$GITHUB_OUTPUT"
+            echo "msg=Coverage check for hugr shows no regression (${change}). ✅ ${codecov}" >> "$GITHUB_OUTPUT"
           else
-            echo "msg=Coverage check for hugr shows regression (${change}). ❌ ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}" >> "$GITHUB_OUTPUT"
+            echo "msg=Coverage check for hugr shows regression (${change}). ❌ ${codecov}" >> "$GITHUB_OUTPUT"
           fi
   notify-slack:
     needs: check-coverage
diff --git a/README.md b/README.md
index fa64b9465..9217bf7bb 100644
--- a/README.md
+++ b/README.md
@@ -3,6 +3,7 @@ quantinuum-hugr
 
 [![build_status][]](https://github.com/CQCL/hugr/actions)
 [![msrv][]](https://github.com/CQCL/hugr)
+[![codecov][]](https://codecov.io/gh/CQCL/hugr)
 
 The Hierarchical Unified Graph Representation (HUGR, pronounced _hugger_) is the
 common representation of quantum circuits and operations in the Quantinuum
@@ -38,4 +39,5 @@ This project is licensed under Apache License, Version 2.0 ([LICENSE][] or http:
 
   [build_status]: https://github.com/CQCL/hugr/workflows/Continuous%20integration/badge.svg?branch=main
   [msrv]: https://img.shields.io/badge/rust-1.70.0%2B-blue.svg
+  [codecov]: https://img.shields.io/codecov/c/gh/CQCL/hugr?logo=codecov
   [LICENSE]: LICENCE