When duplicate posts appear in the RSS feed, the first step is to check for W3C errors in your entries. You can validate your RSS feed at W3C.
If your feed passes W3C validation but duplicate posts still persist, this could be due to the change in the GUID of an existing feed item, which would cause the Applet to Trigger again. We have created a workaround using Google Sheets to log feed items and filter duplicates. Just follow these steps:
1. Create a new Applet (refer to our guide for instructions). Head to ifttt.com/create.
2. To create a Trigger, click the button 'Add', search for the RSS feed service, then press 'Create Trigger'.
3. Choose New Feed Item and enter the URL of your RSS feed.
4. To create an Action, press add to the right of Then That, search for and select the Google Sheets - Add row to spreadsheet Action.
5. In the "Formatted row" field, enter {{EntryTitle}}. Complete the other fields as appropriate. Then, hit 'Create Action' to save the Action.
6. To add a Query, click the + sign in between the Trigger and Action, then add the "Google Sheets - History of rows added to spreadsheet" Query. Ensure you specify the same spreadsheet from step 5.
7. Manually add one row of data to your Google spreadsheet. It doesn't matter what you enter; this step ensures the Google Sheets Query will return data.
8. Finally, to add filter code, click the + sign in between the Trigger and Action once more, then add the following code:
let title = Feed.newFeedItem.EntryTitle;
let lastTitle = GoogleSheets.recentRowsInSpreadsheet[0].ColumnA;
if ( title === lastTitle ) {
//your action here;
}Remember to update the Action for the skip filter code
This method should effectively identify and filter out duplicate posts in your RSS feed.