Google Ads Script to Check Landing Pages for 404s

/**
 * Google Ads Script: 404 Checker with Email Alerts
 * Scans all ENABLED ads in ENABLED ad groups and campaigns.
 * Flags 404 on final URLs, labels them, logs them, and sends an email summary.
 */

var CONFIG = {
  includeMobileFinalUrl: true,
  labelName404: "LP_404",
  userAgent: "Mozilla/5.0 (Google Ads 404 Checker)",
  fetchTimeoutMs: 10000,
  throttleMsBetweenFetches: 75,
  maxAdsToProcess: 5000,
  // Set to a URL to test one-off, or leave empty to skip the debug fetch.
  DEBUG_TEST_URL: "", // e.g. "https://example.com/definitely-not-found-404"

  // --- EMAIL SETTINGS ---
  emailRecipients: [
    "you@example.com"  // <-- replace with your notification email(s)
  ],
  emailSubject: "Google Ads 404 Alert - Broken Landing Pages Detected",
  emailSenderName: "Google Ads 404 Checker"
};

function main() {
  var start = new Date();
  Logger.log("=== 404 CHECKER START === " + start.toISOString());

  ensureLabel(CONFIG.labelName404);

  var processed = 0;
  var hits404 = 0;
  var hitDetails = [];

  try {
    // Debug test URL
    if (CONFIG.DEBUG_TEST_URL) {
      var testStatus = getStatus(CONFIG.DEBUG_TEST_URL);
      Logger.log("[DEBUG] Fetched " + CONFIG.DEBUG_TEST_URL + " -> " + testStatus);
    }

    // Select all enabled ads in enabled ad groups & campaigns
    var adSelector = AdsApp.ads()
      .withCondition("CampaignStatus = ENABLED")
      .withCondition("AdGroupStatus = ENABLED")
      .withCondition("Status = ENABLED")
      .forDateRange("ALL_TIME")
      .orderBy("CampaignName ASC")
      .orderBy("AdGroupName ASC")
      .orderBy("Id ASC")
      .withLimit(CONFIG.maxAdsToProcess);

    var it = adSelector.get();

    while (it.hasNext()) {
      var ad = it.next();

      var finalUrl = safeGetFinalUrl(ad);
      var mobileUrl = CONFIG.includeMobileFinalUrl ? safeGetMobileUrl(ad) : null;

      // FINAL URL
      if (finalUrl) {
        var status = getStatus(finalUrl);
        if (status === 404) {
          hits404++;
          hitDetails.push(recordHit(ad, "FINAL", finalUrl, status));
          label404(ad);
        }
        politeSleep();
      }

      // MOBILE URL (if present and different)
      if (mobileUrl && mobileUrl !== finalUrl) {
        var mStatus = getStatus(mobileUrl);
        if (mStatus === 404) {
          hits404++;
          hitDetails.push(recordHit(ad, "MOBILE", mobileUrl, mStatus));
          label404(ad);
        }
        politeSleep();
      }

      processed++;
    }

  } catch (e) {
    Logger.log("!! ERROR: " + e + "\n" + (e && e.stack ? e.stack : ""));
  } finally {
    logSummary(processed, hits404, start);

    // Send email if 404s were found
    if (hits404 > 0) {
      sendEmailReport(hitDetails, processed, hits404, start);
    }
  }
}

/************** Helper Functions **************/

function ensureLabel(name) {
  var it = AdsApp.labels().withCondition('Name = "' + name + '"').get();
  if (!it.hasNext()) AdsApp.createLabel(name);
}

function safeGetFinalUrl(ad) {
  try { return ad.urls().getFinalUrl(); } catch (e) { return null; }
}

function safeGetMobileUrl(ad) {
  try { return ad.urls().getMobileFinalUrl(); } catch (e) { return null; }
}

function getStatus(url) {
  try {
    var resp = UrlFetchApp.fetch(url, {
      method: "get",
      followRedirects: true,
      muteHttpExceptions: true,
      validateHttpsCertificates: true,
      headers: { "User-Agent": CONFIG.userAgent },
      timeout: CONFIG.fetchTimeoutMs
    });
    return resp.getResponseCode();
  } catch (e) {
    Logger.log("Fetch error for " + url + " -> " + e);
    return null;
  }
}

function label404(ad) {
  try { ad.applyLabel(CONFIG.labelName404); } catch (e) {}
}

function recordHit(ad, type, url, status) {
  var campaign = ad.getCampaign().getName();
  var adGroup = ad.getAdGroup().getName();
  var adId = ad.getId();
  var adType = "";
  try { adType = ad.getType(); } catch (e) {}
  var msg = "[404] " + type + " | Campaign: " + campaign +
            " | AdGroup: " + adGroup +
            " | AdID: " + adId +
            " | Type: " + adType +
            " | URL: " + url +
            " | Status: " + status;
  Logger.log(msg);
  return { campaign: campaign, adGroup: adGroup, adId: adId, type: type, url: url, status: status };
}

function politeSleep() {
  if (CONFIG.throttleMsBetweenFetches > 0) Utilities.sleep(CONFIG.throttleMsBetweenFetches);
}

function logSummary(processed, hits, start) {
  var end = new Date();
  Logger.log("=== 404 CHECKER END === " + end.toISOString());
  Logger.log("Runtime (s): " + Math.round((end - start) / 1000));
  Logger.log("Ads processed: " + processed);
  Logger.log("404 hits: " + hits);
  Logger.log("Label: " + CONFIG.labelName404);
}

/************** EMAIL REPORT **************/

function sendEmailReport(hitDetails, processed, hits404, start) {
  var end = new Date();
  var runtime = Math.round((end - start) / 1000);

  var html = `
    <h2>Google Ads 404 Checker Report</h2>
    <p><strong>Date:</strong> ${start.toISOString()}</p>
    <p><strong>Runtime:</strong> ${runtime} seconds</p>
    <p><strong>Total Ads Processed:</strong> ${processed}</p>
    <p><strong>404 Errors Found:</strong> ${hits404}</p>
    <hr>
    <table border="1" cellpadding="6" cellspacing="0" style="border-collapse:collapse;">
      <tr><th>Campaign</th><th>Ad Group</th><th>Ad ID</th><th>Type</th><th>Status</th><th>URL</th></tr>
      ${hitDetails.map(function(h) {
        return `<tr>
          <td>${h.campaign}</td>
          <td>${h.adGroup}</td>
          <td>${h.adId}</td>
          <td>${h.type}</td>
          <td>${h.status}</td>
          <td><a href="${h.url}" target="_blank">${h.url}</a></td>
        </tr>`;
      }).join("")}
    </table>
    <p>All affected ads have been labeled <strong>${CONFIG.labelName404}</strong>.</p>
  `;

  MailApp.sendEmail({
    to: CONFIG.emailRecipients.join(","),
    subject: CONFIG.emailSubject,
    htmlBody: html,
    name: CONFIG.emailSenderName
  });

  Logger.log("Email sent to: " + CONFIG.emailRecipients.join(", "));
}