Transparent tracking pixel for email open detection

📌 Description This workflow serves a 1x1 transparent PNG image via a webhook, which can be embedded in an email to track when the email is opened. When the image is loaded by the recipient's email client, the webhook is triggered, optionally capturing a userId to identify who opened the email. 📂 Workflow Steps 1. Webhook Trigger (Request img) - Path: /webhook/change-with-your-id - Triggered by an HTTP request (e.g. when the image is loaded in an email). - Accepts a query parameter id to identify the recipient. 2. Set Base64 Data (Create data pix) - Creates a variable data containing a Base64-encoded transparent PNG image (1x1 pixel). 3. Convert to Binary (Create img bin) - Converts the Base64 data string into a binary file. - Sets MIME type to image/png. 4. Respond to Webhook (Respond to Webhook) - Sends the binary image file in the HTTP response. 5. Logging (Do anything to log) - Placeholder node to log or process the id or request metadata. - You can access the id using {{$json"query""id"}}. - You can also use any parameter you want ✉️ How to Use in Emails Embed the image in an HTML email like this: html <img src="https://&lt;your-n8n-instance&gt;/webhook/db4880e7-2134-4994-94e5-a4a3aa120440?id=1234" width="1" height="1" alt / When the email is opened and the image is loaded, the workflow will be triggered. 🛠️ Notes - Some email clients block images by default; this may prevent tracking. - You can enhance the workflow to store open events in a database, log the timestamp, IP, or user agent. - Make sure to comply with data privacy and consent regulations (e.g. GDPR).