diff --git a/src/options/optionsCommon.js b/src/options/optionsCommon.js
new file mode 100644
index 0000000..c552da2
--- /dev/null
+++ b/src/options/optionsCommon.js
@@ -0,0 +1,255 @@
+import {getExtVersion, isFirefox, isReleaseVersion} from '../common/extUtils.js';
+import {cleanUpOptions, optionsPrototype, specialOptions} from '../common/optionsUtils.js';
+import optionsPage from './optionsPage.json5';
+
+var savedSuccessfullyTimeout = null;
+
+const exclusiveOptions = [['thread', 'threadall']];
+
+// Get a URL to a document which is part of the extension documentation (using
+// |ref| as the Git ref).
+function getDocURLWithRef(doc, ref) {
+  return 'https://gerrit.avm99963.com/plugins/gitiles/infinitegforums/+/' +
+      ref + '/docs/' + doc;
+}
+
+// Get a URL to a document which is part of the extension documentation
+// (autodetect the appropriate Git ref)
+function getDocURL(doc) {
+  if (!isReleaseVersion()) return getDocURLWithRef(doc, 'HEAD');
+
+  var version = getExtVersion();
+  return getDocURLWithRef(doc, 'refs/tags/v' + version);
+}
+
+// Get the value of the option set in the options/experiments page
+function getOptionValue(opt) {
+  if (specialOptions.includes(opt)) {
+    switch (opt) {
+      case 'profileindicatoralt_months':
+        return document.getElementById(opt).value || 12;
+
+      case 'ccdarktheme_mode':
+        return document.getElementById(opt).value || 'switch';
+
+      case 'ccdragndropfix':
+        return document.getElementById(opt).checked || false;
+
+      default:
+        console.warn('Unrecognized option: ' + opt);
+        return undefined;
+    }
+  }
+
+  return document.getElementById(opt).checked || false;
+}
+
+// Returns whether the option is included in the current context
+function isOptionShown(opt) {
+  if (!optionsPrototype.hasOwnProperty(opt)) return false;
+  return optionsPrototype[opt].context == window.CONTEXT;
+}
+
+function save(e) {
+  // Validation checks before saving
+  if (isOptionShown('profileindicatoralt_months')) {
+    var months = document.getElementById('profileindicatoralt_months');
+    if (!months.checkValidity()) {
+      console.warn(months.validationMessage);
+      return;
+    }
+  }
+
+  e.preventDefault();
+
+  chrome.storage.sync.get(null, function(items) {
+    var options = cleanUpOptions(items, true);
+
+    // Save
+    Object.keys(options).forEach(function(opt) {
+      if (!isOptionShown(opt)) return;
+      options[opt] = getOptionValue(opt);
+    });
+
+    chrome.storage.sync.set(options, function() {
+      window.close();
+
+      // In browsers like Firefox window.close is not supported:
+      if (savedSuccessfullyTimeout !== null)
+        window.clearTimeout(savedSuccessfullyTimeout);
+
+      document.getElementById('save-indicator').innerText =
+          '✓ ' + chrome.i18n.getMessage('options_saved');
+      savedSuccessfullyTimeout = window.setTimeout(_ => {
+        document.getElementById('save-indicator').innerText = '';
+      }, 3699);
+    });
+  });
+}
+
+function i18n() {
+  document.querySelectorAll('[data-i18n]')
+      .forEach(
+          el => el.innerHTML = chrome.i18n.getMessage(
+              'options_' + el.getAttribute('data-i18n')));
+}
+
+window.addEventListener('load', function() {
+  if (window.CONTEXT == 'options') {
+    if (!isReleaseVersion()) {
+      var experimentsLink = document.querySelector('.experiments-link');
+      experimentsLink.removeAttribute('hidden');
+      experimentsLink.addEventListener('click', _ => chrome.tabs.create({
+        url: chrome.runtime.getURL('options/experiments.html'),
+      }));
+    }
+
+    // Add options to page
+    let optionsContainer = document.getElementById('options-container');
+    for (let section of optionsPage.sections) {
+      if (section?.name) {
+        let sectionHeader = document.createElement('h4');
+        sectionHeader.setAttribute('data-i18n', section.name);
+        optionsContainer.append(sectionHeader);
+      }
+
+      if (section?.options) {
+        for (let option of section.options) {
+          if (option?.customHTML) {
+            optionsContainer.insertAdjacentHTML('beforeend', option.customHTML);
+            continue;
+          }
+
+          let optionEl = document.createElement('div');
+          optionEl.classList.add('option');
+
+          let checkbox = document.createElement('input');
+          checkbox.setAttribute('type', 'checkbox');
+          checkbox.id = option.codename;
+
+          let label = document.createElement('label');
+          label.setAttribute('for', checkbox.id);
+          label.setAttribute('data-i18n', option.codename);
+
+          optionEl.append(checkbox, ' ', label);
+
+          if (option?.experimental) {
+            let experimental = document.createElement('span');
+            experimental.classList.add('experimental-label');
+            experimental.setAttribute('data-i18n', 'experimental_label');
+
+            optionEl.append(experimental);
+          }
+
+          optionsContainer.append(optionEl);
+        }
+      }
+
+      if (section?.footerHTML) {
+        optionsContainer.insertAdjacentHTML('beforeend', section.footerHTML);
+      }
+    }
+
+    var featuresLink = document.querySelector('.features-link');
+    featuresLink.href = getDocURL('features.md');
+
+    var profileIndicatorLink =
+        document.getElementById('profileIndicatorMoreInfo');
+    profileIndicatorLink.href = getDocURL('op_indicator.md');
+  }
+
+  i18n();
+
+  chrome.storage.sync.get(null, function(items) {
+    items = cleanUpOptions(items, false);
+
+    // If some features have been force disabled, communicate this to the user.
+    if (items?._forceDisabledFeatures &&
+        items._forceDisabledFeatures.length > 0) {
+      if (window.CONTEXT == 'options') {
+        document.getElementById('kill-switch-warning')
+            .removeAttribute('hidden');
+      }
+
+      // TODO(avm99963): show a message above each option that has been force
+      // disabled
+    }
+
+    for (var entry of Object.entries(optionsPrototype)) {
+      var opt = entry[0];
+      var optMeta = entry[1];
+
+      if (!isOptionShown(opt)) continue;
+
+      if (specialOptions.includes(opt)) {
+        switch (opt) {
+          case 'profileindicatoralt_months':
+            var input = document.createElement('input');
+            input.type = 'number';
+            input.id = 'profileindicatoralt_months';
+            input.max = '12';
+            input.min = '1';
+            input.value = items[opt];
+            input.required = true;
+            document.getElementById('profileindicatoralt_months--container')
+                .appendChild(input);
+            break;
+
+          case 'ccdarktheme_mode':
+            var select = document.createElement('select');
+            select.id = 'ccdarktheme_mode';
+
+            const modes = ['switch', 'system'];
+            for (const mode of modes) {
+              var modeOption = document.createElement('option');
+              modeOption.value = mode;
+              modeOption.textContent =
+                  chrome.i18n.getMessage('options_ccdarktheme_mode_' + mode);
+              if (items.ccdarktheme_mode == mode) modeOption.selected = true;
+              select.appendChild(modeOption);
+            }
+
+            document.getElementById('ccdarktheme_mode--container')
+                .appendChild(select);
+            break;
+
+          // Firefox doesn't support drag and dropping bookmarks into the text
+          // editor while preserving the bookmark title.
+          case 'ccdragndropfix':
+            var showOption = !isFirefox();
+            if (showOption) {
+              document.getElementById('dragndrop-wrapper')
+                  .removeAttribute('hidden');
+
+              if (items[opt] === true)
+                document.getElementById(opt).checked = true;
+            }
+            break;
+
+          default:
+            console.warn('Unrecognized option: ' + opt);
+            break;
+        }
+        continue;
+      }
+
+      if (items[opt] === true) document.getElementById(opt).checked = true;
+    }
+
+    exclusiveOptions.forEach(exclusive => {
+      if (!isOptionShown(exclusive[0]) || !isOptionShown(exclusive[1])) return;
+
+      exclusive.forEach(
+          el => document.getElementById(el).addEventListener('change', e => {
+            if (document.getElementById(exclusive[0]).checked &&
+                document.getElementById(exclusive[1]).checked) {
+              document
+                  .getElementById(
+                      exclusive[(e.currentTarget.id == exclusive[0] ? 1 : 0)])
+                  .checked = false;
+            }
+          }));
+    });
+    document.querySelector('#save').addEventListener('click', save);
+  });
+});