Open and Click Tracking

Open and click tracking is disabled by default for all domains. You can enable it manually or programmatically.

While participating in the custom tracking domains beta, open and click tracking is only active when all three conditions are met:

The open_tracking or click_tracking setting is enabled for the domain.
A custom tracking domain is configured.
The tracking domain CNAME record has been verified.

Using the dashboard
Using the API

Go to the Domains page and click on the domain you want to configure.In the Configuration tab, you can enable open and/or click tracking.

You can also programmatically enable open and/or click tracking by using the API.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.domains.update({
  id: 'b8617ad3-b712-41d9-81a0-f7c3d879314e',
  openTracking: false,
  clickTracking: true,
});

View the API reference for more details.

For best deliverability, we recommend disabling click and open tracking for sensitive transactional emails.

How Open Tracking Works

A 1x1 pixel transparent GIF image is inserted in each email and includes a unique reference to this image file. When the image is downloaded, Resend can tell exactly which message was opened and by whom.

How Click Tracking Works

To track clicks, Resend modifies each link in the body of the HTML email. When recipients open a link, they are sent through a Resend server, and then immediately to the URL destination.

Custom Tracking Domain

You can configure a custom domain for all click and open urls in your emails. When configured, Resend modifies each link in the body of the HTML to pass through Resend servers using this domain.

Custom tracking domains are currently in private alpha and only available to a limited number of users. APIs might change before GA.To use the methods on this page, you must upgrade your Resend SDK:

npm install resend@6.10.0-preview-tracking-domains.3

A tracking domain will always share the same root domain as your sending domain. This improves deliverability and brand consistency. Similar to verifying your sending domain, you will need to add a CNAME record to your DNS settings to verify your tracking domain. Once verified, all tracked links in your emails will use your custom tracking domain (e.g., links.emails.yourdomain.com). This value can only be changed after it has been specified, never removed. This is to preserve any email links that may already be sent with the current tracking subdomain. After changing the tracking subdomain, a new DNS record must be verified, until then, the previous value is used. Do not remove old tracking DNS records, all previously used records remain active and are included in the response. Changes are limited to once every 24 hours. Removing a domain with a configured custom tracking subdomain will also remove the Resend provisioned proxy, breaking any existing email links that use that subdomain. To keep links working, set up your own proxy pointing to Resend’s tracking DNS records before removing the domain. Here’s how to configure click_tracking with a custom tracking domain:

Using the dashboard
Using the API

Look for the Custom Tracking Domain section, and click on Configure.

Then, you will need to add a CNAME record to verify your tracking domain.

Once verified, all tracked links in your emails will use your custom tracking domain.

You can configure a custom tracking domain when creating a new domain by passing the tracking_subdomain field along with click_tracking and/or open_tracking.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.domains.create({
  name: 'example.com',
  clickTracking: true,
  trackingSubdomain: 'links',
});

If you already have a domain, you can add a custom tracking subdomain and enable tracking by updating it.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.domains.update({
  id: 'd91cd9bd-1176-453e-8fc1-35364d380206',
  clickTracking: true,
  trackingSubdomain: 'links',
});

Then, verify the domain to check the tracking CNAME record.

import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.domains.verify(
  'd91cd9bd-1176-453e-8fc1-35364d380206',
);

Once verified, all tracked links in your emails will use your custom tracking domain.

Documentation

Quickstart

Learn

Resources

Open and Click Tracking

How Open Tracking Works

How Click Tracking Works

Custom Tracking Domain

Documentation

Quickstart

Learn

Resources

​How Open Tracking Works

​How Click Tracking Works

​Custom Tracking Domain

How Open Tracking Works

How Click Tracking Works

Custom Tracking Domain