diff --git a/src/background/content-script.js b/src/background/content-script.js
new file mode 100644
index 0000000..8be3c26
--- /dev/null
+++ b/src/background/content-script.js
@@ -0,0 +1,12 @@
+import browser from "webextension-polyfill";
+
+browser.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {
+  browser.tabs.executeScript(tabId, {
+    file: 'content_script/input_tools.js',
+    runAt: 'document_idle',
+  });
+
+  browser.tabs.insertCSS(tabId, {
+    file: 'content_script/input_tools.css',
+  });
+});
\ No newline at end of file
diff --git a/src/background/index.js b/src/background/index.js
index 1068bb4..622f804 100644
--- a/src/background/index.js
+++ b/src/background/index.js
@@ -1,10 +1,11 @@
+import browser from "webextension-polyfill";
 import APIService from "../popup/APIService";
 import SLStorage from "../popup/SLStorage";
+import "./content-script";
 
 import { handleNewRandomAlias } from "./create-alias";
 import { handleOnClickContextMenu } from "./context-menu";
 
-global.browser = require("webextension-polyfill");
 global.isBackgroundJS = true;
 
 /**
@@ -24,7 +25,7 @@ async function handleGetAppSettings() {
 /**
  * Register onMessage listener
  */
-global.browser.runtime.onMessage.addListener(async function (request, sender) {
+browser.runtime.onMessage.addListener(async function (request, sender) {
   if (request.tag === "NEW_RANDOM_ALIAS") {
     return await handleNewRandomAlias(sender.tab);
   } else if (request.tag === "GET_APP_SETTINGS") {
@@ -35,7 +36,7 @@ global.browser.runtime.onMessage.addListener(async function (request, sender) {
 /**
  * Register context menu
  */
-global.browser.contextMenus.create({
+browser.contextMenus.create({
   title: "Create random email alias (copied)",
   contexts: ["all"],
   onclick: handleOnClickContextMenu,
diff --git a/src/content_script/input_tools.js b/src/content_script/input_tools.js
index 352e30f..5be266d 100644
--- a/src/content_script/input_tools.js
+++ b/src/content_script/input_tools.js
@@ -1,235 +1,237 @@
-let SLSettings = {};
+if (!typeof InputTools !== 'undefined') {
+  let SLSettings = {};
 
-const InputTools = {
-  isLoading: false,
+  const InputTools = {
+    isLoading: false,
 
-  // store tracked input elements
-  trackedElements: [],
+    // store tracked input elements
+    trackedElements: [],
 
-  init(target) {
-    InputTools.queryEmailInputAndApply(target, (element) => {
-      if (!InputTools.isValidEmailInput(element)) {
+    init(target) {
+      InputTools.queryEmailInputAndApply(target, (element) => {
+        if (!InputTools.isValidEmailInput(element)) {
+          return;
+        }
+
+        // ignore if this elements has already been tracked
+        const i = InputTools.trackedElements.indexOf(element);
+        if (i === -1) {
+          InputTools.trackedElements.push(element);
+          InputTools.addSLButtonToInput(element);
+        }
+      });
+    },
+
+    destroy(target) {
+      InputTools.queryEmailInputAndApply(target, (element) => {
+        // remove element from tracking list
+        const i = InputTools.trackedElements.indexOf(element);
+        if (i !== -1) {
+          InputTools.trackedElements.splice(i, 1);
+        }
+      });
+    },
+
+    queryEmailInputAndApply(target, actionFunction) {
+      if (!target.querySelectorAll) return;
+      const elements = target.querySelectorAll(
+        "input[type='email'],input[name*='email'],input[id*='email']"
+      );
+      for (const element of elements) {
+        actionFunction(element);
+      }
+    },
+
+    isValidEmailInput(element) {
+      const style = getComputedStyle(element);
+      return (
+        // check if element is visible
+        style.visibility !== "hidden" &&
+        style.display !== "none" &&
+        style.opacity !== "0" &&
+        style.pointerEvents === "auto" &&
+        // check if element is not disabled
+        !element.disabled &&
+        // for example, we must filter out a checkbox with name*=email
+        // check if element is text or email input
+        (element.type === "text" || element.type === "email")
+      );
+    },
+
+    addSLButtonToInput(inputElem) {
+      // create wrapper for SL button
+      const btnWrapper = InputTools.newDiv("sl-button-wrapper");
+      const inputSumHeight = inputElem.getBoundingClientRect().height + "px";
+      btnWrapper.style.height = inputSumHeight;
+      btnWrapper.style.width = inputSumHeight;
+      document.body.appendChild(btnWrapper);
+
+      // create the SL button
+      const slButton = InputTools.newDiv("sl-button");
+      slButton.addEventListener("click", function () {
+        InputTools.handleOnClickSLButton(inputElem, slButton);
+      });
+      slButton.style.height = inputSumHeight;
+      slButton.style.width = inputSumHeight;
+      btnWrapper.appendChild(slButton);
+
+      InputTools.placeBtnToTheRightOfElement(inputElem, btnWrapper);
+    },
+
+    newDiv(...className) {
+      const div = document.createElement("div");
+      div.classList.add(...className);
+      return div;
+    },
+
+    placeBtnToTheRightOfElement(inputElem, btnWrapper) {
+      let intervalId = 0;
+
+      function updatePosition() {
+        // check is element is removed from trackedElements
+        const i = InputTools.trackedElements.indexOf(inputElem);
+        if (i === -1) {
+          btnWrapper.parentNode.removeChild(btnWrapper);
+          clearInterval(intervalId);
+        }
+
+        // get dimension & position of input
+        const inputCoords = inputElem.getBoundingClientRect();
+        const inputStyle = getComputedStyle(inputElem);
+        const elemWidth = InputTools.dimensionToInt(btnWrapper.style.width);
+        const pageXOffset = window.pageXOffset;
+        const pageYOffset = window.pageYOffset;
+        const buttonXOffset =
+          SLSettings.SLButtonPosition === "right-inside"
+            ? -elemWidth * 1.02
+            : elemWidth * 0.02;
+
+        // calculate elem position
+        const left =
+          InputTools.sumPixel([
+            inputCoords.left,
+            pageXOffset,
+            inputElem.offsetWidth,
+            buttonXOffset,
+            -inputStyle.paddingRight,
+          ]) + "px";
+
+        const top = InputTools.sumPixel([inputCoords.top, pageYOffset]) + "px";
+
+        if (btnWrapper.style.left !== left) {
+          btnWrapper.style.left = left;
+        }
+
+        if (btnWrapper.style.top !== top) {
+          btnWrapper.style.top = top;
+        }
+      }
+
+      intervalId = setInterval(updatePosition, 200);
+      updatePosition();
+    },
+
+    async handleOnClickSLButton(inputElem, slButton) {
+      if (InputTools.isLoading) {
         return;
       }
+      InputTools.isLoading = true;
+      slButton.classList.add("loading");
 
-      // ignore if this elements has already been tracked
-      const i = InputTools.trackedElements.indexOf(element);
-      if (i === -1) {
-        InputTools.trackedElements.push(element);
-        InputTools.addSLButtonToInput(element);
-      }
-    });
-  },
-
-  destroy(target) {
-    InputTools.queryEmailInputAndApply(target, (element) => {
-      // remove element from tracking list
-      const i = InputTools.trackedElements.indexOf(element);
-      if (i !== -1) {
-        InputTools.trackedElements.splice(i, 1);
-      }
-    });
-  },
-
-  queryEmailInputAndApply(target, actionFunction) {
-    if (!target.querySelectorAll) return;
-    const elements = target.querySelectorAll(
-      "input[type='email'],input[name*='email'],input[id*='email']"
-    );
-    for (const element of elements) {
-      actionFunction(element);
-    }
-  },
-
-  isValidEmailInput(element) {
-    const style = getComputedStyle(element);
-    return (
-      // check if element is visible
-      style.visibility !== "hidden" &&
-      style.display !== "none" &&
-      style.opacity !== "0" &&
-      style.pointerEvents === "auto" &&
-      // check if element is not disabled
-      !element.disabled &&
-      // for example, we must filter out a checkbox with name*=email
-      // check if element is text or email input
-      (element.type === "text" || element.type === "email")
-    );
-  },
-
-  addSLButtonToInput(inputElem) {
-    // create wrapper for SL button
-    const btnWrapper = InputTools.newDiv("sl-button-wrapper");
-    const inputSumHeight = inputElem.getBoundingClientRect().height + "px";
-    btnWrapper.style.height = inputSumHeight;
-    btnWrapper.style.width = inputSumHeight;
-    document.body.appendChild(btnWrapper);
-
-    // create the SL button
-    const slButton = InputTools.newDiv("sl-button");
-    slButton.addEventListener("click", function () {
-      InputTools.handleOnClickSLButton(inputElem, slButton);
-    });
-    slButton.style.height = inputSumHeight;
-    slButton.style.width = inputSumHeight;
-    btnWrapper.appendChild(slButton);
-
-    InputTools.placeBtnToTheRightOfElement(inputElem, btnWrapper);
-  },
-
-  newDiv(...className) {
-    const div = document.createElement("div");
-    div.classList.add(...className);
-    return div;
-  },
-
-  placeBtnToTheRightOfElement(inputElem, btnWrapper) {
-    let intervalId = 0;
-
-    function updatePosition() {
-      // check is element is removed from trackedElements
-      const i = InputTools.trackedElements.indexOf(inputElem);
-      if (i === -1) {
-        btnWrapper.parentNode.removeChild(btnWrapper);
-        clearInterval(intervalId);
+      let res = await sendMessageToBackground("NEW_RANDOM_ALIAS");
+      if (res.error) {
+        alert("SimpleLogin Error: " + res.error);
+        res = { alias: "" };
       }
 
-      // get dimension & position of input
-      const inputCoords = inputElem.getBoundingClientRect();
-      const inputStyle = getComputedStyle(inputElem);
-      const elemWidth = InputTools.dimensionToInt(btnWrapper.style.width);
-      const pageXOffset = window.pageXOffset;
-      const pageYOffset = window.pageYOffset;
-      const buttonXOffset =
-        SLSettings.SLButtonPosition === "right-inside"
-          ? -elemWidth * 1.02
-          : elemWidth * 0.02;
+      InputTools.isLoading = false;
+      slButton.classList.remove("loading");
 
-      // calculate elem position
-      const left =
-        InputTools.sumPixel([
-          inputCoords.left,
-          pageXOffset,
-          inputElem.offsetWidth,
-          buttonXOffset,
-          -inputStyle.paddingRight,
-        ]) + "px";
+      inputElem.value = res.alias;
+    },
 
-      const top = InputTools.sumPixel([inputCoords.top, pageYOffset]) + "px";
-
-      if (btnWrapper.style.left !== left) {
-        btnWrapper.style.left = left;
+    sumPixel(dimensions) {
+      let sum = 0;
+      for (const dim of dimensions) {
+        sum += !isNaN(dim) ? dim : InputTools.dimensionToInt(dim);
       }
+      return sum;
+    },
 
-      if (btnWrapper.style.top !== top) {
-        btnWrapper.style.top = top;
+    dimensionToInt(dim) {
+      try {
+        const pixel = parseFloat(dim.replace(/[^0-9.]+/g, ""));
+        return isNaN(pixel) ? 0 : pixel;
+      } catch (e) {
+        return 0;
       }
-    }
+    },
+  };
 
-    intervalId = setInterval(updatePosition, 200);
-    updatePosition();
-  },
+  const MutationObserver =
+    window.MutationObserver ||
+    window.WebKitMutationObserver ||
+    window.MozMutationObserver;
 
-  async handleOnClickSLButton(inputElem, slButton) {
-    if (InputTools.isLoading) {
-      return;
-    }
-    InputTools.isLoading = true;
-    slButton.classList.add("loading");
-
-    let res = await sendMessageToBackground("NEW_RANDOM_ALIAS");
-    if (res.error) {
-      alert("SimpleLogin Error: " + res.error);
-      res = { alias: "" };
-    }
-
-    InputTools.isLoading = false;
-    slButton.classList.remove("loading");
-
-    inputElem.value = res.alias;
-  },
-
-  sumPixel(dimensions) {
-    let sum = 0;
-    for (const dim of dimensions) {
-      sum += !isNaN(dim) ? dim : InputTools.dimensionToInt(dim);
-    }
-    return sum;
-  },
-
-  dimensionToInt(dim) {
-    try {
-      const pixel = parseFloat(dim.replace(/[^0-9.]+/g, ""));
-      return isNaN(pixel) ? 0 : pixel;
-    } catch (e) {
-      return 0;
-    }
-  },
-};
-
-const MutationObserver =
-  window.MutationObserver ||
-  window.WebKitMutationObserver ||
-  window.MozMutationObserver;
-
-/**
- * Add DOM mutations listener
- */
-function addMutationObserver() {
-  const mutationObserver = new MutationObserver(function (mutations) {
-    mutations.forEach(function (mutation) {
-      for (const addedNode of mutation.addedNodes) {
-        // add SLButton for newly added nodes
-        InputTools.init(addedNode);
-      }
-
-      for (const removedNode of mutation.removedNodes) {
-        // destroy SLButton for removed nodes
-        InputTools.destroy(removedNode);
-      }
-    });
-  });
-
-  const target = document.body;
-  if (!target) return;
-
-  mutationObserver.observe(target, {
-    childList: true,
-    subtree: true,
-  });
-}
-
-/**
- * Send message to background.js and resolve with the response
- * @param {string} tag
- * @param {object} data
- */
-function sendMessageToBackground(tag, data = null) {
-  const _browser = window.chrome || browser;
-  return new Promise((resolve) => {
-    try {
-      _browser.runtime.sendMessage(
-        {
-          tag,
-          data,
-        },
-        function (response) {
-          resolve(response);
+  /**
+   * Add DOM mutations listener
+   */
+  function addMutationObserver() {
+    const mutationObserver = new MutationObserver(function (mutations) {
+      mutations.forEach(function (mutation) {
+        for (const addedNode of mutation.addedNodes) {
+          // add SLButton for newly added nodes
+          InputTools.init(addedNode);
         }
-      );
-    } catch (e) {
-      // Extension context invalidated.
-      console.error(e);
-    }
-  });
-}
 
-async function initModule() {
-  SLSettings = await sendMessageToBackground("GET_APP_SETTINGS");
-  if (SLSettings.showSLButton) {
-    InputTools.init(document);
-    addMutationObserver();
+        for (const removedNode of mutation.removedNodes) {
+          // destroy SLButton for removed nodes
+          InputTools.destroy(removedNode);
+        }
+      });
+    });
+
+    const target = document.body;
+    if (!target) return;
+
+    mutationObserver.observe(target, {
+      childList: true,
+      subtree: true,
+    });
   }
-}
 
-initModule();
+  /**
+   * Send message to background.js and resolve with the response
+   * @param {string} tag
+   * @param {object} data
+   */
+  function sendMessageToBackground(tag, data = null) {
+    const _browser = window.chrome || browser;
+    return new Promise((resolve) => {
+      try {
+        _browser.runtime.sendMessage(
+          {
+            tag,
+            data,
+          },
+          function (response) {
+            resolve(response);
+          }
+        );
+      } catch (e) {
+        // Extension context invalidated.
+        console.error(e);
+      }
+    });
+  }
+
+  async function initModule() {
+    SLSettings = await sendMessageToBackground("GET_APP_SETTINGS");
+    if (SLSettings.showSLButton) {
+      InputTools.init(document);
+      addMutationObserver();
+    }
+  }
+
+  initModule();
+}
\ No newline at end of file
diff --git a/src/manifest.json b/src/manifest.json
index a5acd67..73494bd 100644
--- a/src/manifest.json
+++ b/src/manifest.json
@@ -8,11 +8,12 @@
     "128": "icons/icon_128.png"
   },
   "permissions": [
-    "activeTab",
     "storage",
     "cookies",
     "contextMenus",
-    "https://*.simplelogin.io/*"
+    "tabs",
+    "http://*/*",
+    "https://*/*"
   ],
   "browser_action": {
     "default_title": "simplelogin-extension",
@@ -27,15 +28,5 @@
     "scripts": [
       "background.js"
     ]
-  },
-  "content_scripts": [
-    {
-      "matches": [
-        "<all_urls>"
-      ],
-      "js": ["content_script/input_tools.js"],
-      "css": ["content_script/input_tools.css"],
-      "all_frames": true
-    }
-  ]
+  }
 }