diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index edf54fa8b0c..85f18e6e2ad 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -9,6 +9,7 @@ Here is a quick guide on how to run Reflex repo locally so you can start contrib
 **Prerequisites:**
 
 - uv version >= 0.6.0 and add it to your path (see [UV Docs](https://docs.astral.sh/uv/getting-started/installation/) for more info).
+- `act` installed and a working Docker daemon if you want to run the local CI script (see [act installation docs](https://nektosact.com/installation/)).
 
 **1. Fork this repository:**
 Fork this repository by clicking on the `Fork` button on the top right.
@@ -64,8 +65,30 @@ Once you solve a current issue or improvement to Reflex, you can make a PR, and
 
 Before submitting, a pull request, ensure the following steps are taken and test passing.
 
-In your `reflex` directory run make sure all the unit tests are still passing using the following command.
-This will fail if code coverage is below 70%.
+In your `reflex` directory, you can run the local CI startup script with:
+
+```bash
+bash scripts/run_all_tests.sh
+```
+
+The script runs selected GitHub Actions jobs locally through `act`:
+
+- `unit-tests` on `ubuntu-latest` with Python `3.13`
+- `integration-app-harness` on `ubuntu-22.04` with Python `3.13`, `memory`, and both split groups
+- `benchmarks`
+- `check_latest_node` for both split groups
+
+Any extra arguments are forwarded to `act`. `-l` / `--list` lists the selected jobs without running them:
+
+```bash
+bash scripts/run_all_tests.sh -l
+```
+
+If Docker is unavailable and you still want to run against your host environment, set `REFLEX_ACT_ALLOW_SELF_HOSTED=1`. In that mode the script scrubs `CODESPACE_NAME`, `GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN`, and `PYTHONSAFEPATH` to reduce host-specific drift. Set `REFLEX_ACT_SELF_HOSTED_PRESERVE_HOST_ENV=1` if you need the raw host environment instead.
+
+Browser-backed workflows still have lower parity in self-hosted mode. If you are running as `root`, prefer a non-root environment; `APP_HARNESS_DRIVER_ARGS=--no-sandbox` is only a local fallback and may still not match GitHub Actions behavior.
+
+If you only need the fast local check, make sure all the unit tests are still passing using the following command. This will fail if code coverage is below 70%.
 
 ```bash
 uv run pytest tests/units --cov --no-cov-on-fail --cov-report=
diff --git a/scripts/run_all_tests.sh b/scripts/run_all_tests.sh
new file mode 100755
index 00000000000..7d6a1fbe78c
--- /dev/null
+++ b/scripts/run_all_tests.sh
@@ -0,0 +1,211 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+repo_root="$(cd "$script_dir/.." && pwd)"
+
+show_help() {
+  cat <<'EOF'
+Usage: bash scripts/run_all_tests.sh [act args]
+
+Run selected Reflex GitHub Actions jobs locally with `act`.
+
+Examples:
+  bash scripts/run_all_tests.sh
+  bash scripts/run_all_tests.sh -l
+
+Environment:
+  ACT_BIN=/path/to/act                      Override the `act` binary.
+  REFLEX_ACT_EVENT=pull_request            Override the event passed to `act`.
+  REFLEX_ACT_UNIT_TESTS_PYTHON_VERSION=3.13
+  REFLEX_ACT_INTEGRATION_PYTHON_VERSION=3.13
+  REFLEX_ACT_INTEGRATION_STATE_MANAGER=memory
+  REFLEX_ACT_PLATFORM_LATEST=...
+  REFLEX_ACT_PLATFORM_22_04=...
+  REFLEX_ACT_ALLOW_SELF_HOSTED=1           Run on the host when Docker is unavailable.
+  REFLEX_ACT_SELF_HOSTED_PRESERVE_HOST_ENV=1
+                                            Keep host-only env vars in self-hosted mode.
+  REFLEX_ACT_SKIP_BENCHMARKS=1             Skip the benchmark workflow.
+EOF
+}
+
+has_arg() {
+  local needle="$1"
+  shift
+  local arg
+
+  for arg in "$@"; do
+    if [[ "$arg" == "$needle" ]]; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
+is_list_mode() {
+  local arg
+
+  for arg in "$@"; do
+    case "$arg" in
+      -l|--list|--list-options)
+        return 0
+        ;;
+    esac
+  done
+
+  return 1
+}
+
+ensure_act() {
+  if [[ -n "$ACT_BIN" && -x "$ACT_BIN" ]]; then
+    return 0
+  fi
+
+  cat >&2 <<'EOF'
+Error: act is required to run the local CI workflow script.
+
+Install it from https://nektosact.com/installation/ or set ACT_BIN to an existing binary.
+EOF
+  exit 1
+}
+
+docker_daemon_available() {
+  command -v docker >/dev/null 2>&1 && docker info >/dev/null 2>&1
+}
+
+self_hosted_mode_enabled() {
+  [[ "${REFLEX_ACT_ALLOW_SELF_HOSTED:-0}" == "1" ]]
+}
+
+require_runner_support() {
+  if is_list_mode "${extra_act_args[@]}"; then
+    return 0
+  fi
+
+  if docker_daemon_available || self_hosted_mode_enabled; then
+    return 0
+  fi
+
+  cat >&2 <<'EOF'
+Error: Docker is required to run Reflex GitHub Actions locally with act.
+
+Use `bash scripts/run_all_tests.sh -l` to list the selected jobs without running them,
+or set REFLEX_ACT_ALLOW_SELF_HOSTED=1 to execute directly on the host with lower CI parity.
+EOF
+  exit 1
+}
+
+configure_platform_args() {
+  local latest_platform
+  local ubuntu_2204_platform
+
+  if self_hosted_mode_enabled; then
+    latest_platform="${REFLEX_ACT_PLATFORM_LATEST:--self-hosted}"
+    ubuntu_2204_platform="${REFLEX_ACT_PLATFORM_22_04:--self-hosted}"
+    echo "Warning: Docker unavailable or bypassed; using self-hosted act platform mapping." >&2
+  else
+    latest_platform="${REFLEX_ACT_PLATFORM_LATEST:-catthehacker/ubuntu:full-latest}"
+    ubuntu_2204_platform="${REFLEX_ACT_PLATFORM_22_04:-catthehacker/ubuntu:full-22.04}"
+  fi
+
+  platform_args=(
+    -P "ubuntu-latest=${latest_platform}"
+    -P "ubuntu-22.04=${ubuntu_2204_platform}"
+  )
+}
+
+configure_self_hosted_env() {
+  if ! self_hosted_mode_enabled; then
+    return 0
+  fi
+
+  if [[ "${REFLEX_ACT_SELF_HOSTED_PRESERVE_HOST_ENV:-0}" == "1" ]]; then
+    echo "Warning: preserving host environment in self-hosted mode." >&2
+    return 0
+  fi
+
+  # Keep host-specific shell state from leaking into workflow behavior.
+  act_env_prefix=(
+    env
+    -u CODESPACE_NAME
+    -u GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN
+    -u GITHUB_CODESPACE_TOKEN
+    -u PYTHONSAFEPATH
+  )
+
+  echo "Warning: self-hosted mode scrubs Codespaces and PYTHONSAFEPATH env vars for better CI parity." >&2
+
+  if [[ "$(id -u)" == "0" ]]; then
+    cat >&2 <<'EOF'
+Warning: browser-based workflows may still fail as root.
+Use a non-root environment for best parity. If you stay on root, try APP_HARNESS_DRIVER_ARGS=--no-sandbox as a local-only fallback.
+EOF
+  fi
+}
+
+run_job() {
+  local workflow="$1"
+  local job="$2"
+  local label="$3"
+  shift 3
+
+  echo "==> ${label}"
+  "${act_env_prefix[@]}" "${ACT_BIN}" \
+    "${ACT_EVENT}" \
+    "${platform_args[@]}" \
+    -W ".github/workflows/${workflow}" \
+    -j "${job}" \
+    "$@" \
+    "${extra_act_args[@]}"
+}
+
+if has_arg "-h" "$@" || has_arg "--help" "$@"; then
+  show_help
+  exit 0
+fi
+
+ACT_BIN="${ACT_BIN:-$(command -v act || true)}"
+ACT_EVENT="${REFLEX_ACT_EVENT:-pull_request}"
+extra_act_args=("$@")
+act_env_prefix=()
+platform_args=()
+
+ensure_act
+require_runner_support
+configure_platform_args
+configure_self_hosted_env
+
+cd "$repo_root"
+
+run_job \
+  "unit_tests.yml" \
+  "unit-tests" \
+  "unit-tests (ubuntu-latest, python ${REFLEX_ACT_UNIT_TESTS_PYTHON_VERSION:-3.13})" \
+  --matrix "os:ubuntu-latest" \
+  --matrix "python-version:${REFLEX_ACT_UNIT_TESTS_PYTHON_VERSION:-3.13}"
+
+for split_index in 1 2; do
+  run_job \
+    "integration_app_harness.yml" \
+    "integration-app-harness" \
+    "integration-app-harness (python ${REFLEX_ACT_INTEGRATION_PYTHON_VERSION:-3.13}, ${REFLEX_ACT_INTEGRATION_STATE_MANAGER:-memory}, split ${split_index})" \
+    --matrix "python-version:${REFLEX_ACT_INTEGRATION_PYTHON_VERSION:-3.13}" \
+    --matrix "state_manager:${REFLEX_ACT_INTEGRATION_STATE_MANAGER:-memory}" \
+    --matrix "split_index:${split_index}"
+done
+
+if [[ "${REFLEX_ACT_SKIP_BENCHMARKS:-0}" != "1" ]]; then
+  run_job \
+    "performance.yml" \
+    "benchmarks" \
+    "benchmarks"
+fi
+
+for split_index in 1 2; do
+  run_job \
+    "check_node_latest.yml" \
+    "check_latest_node" \
+    "check-node-latest (split ${split_index})" \
+    --matrix "split_index:${split_index}"
+done