Why Is My Binary Data Item Empty in the Workflow?

Below are a few things to check and adjust in your workflow when sending binary files via nodes like HTTP Request or Dropbox:

1. Verify the Binary Property Name

n8n stores binary file data on each item under a property name (for example, data) separate from JSON fields. Make sure that the node sending the binary data (HTTP Request or Dropbox) is configured to use the correct binary property name where your image resides. For instance, in the HTTP Request node you may need to set the “Binary Property” field to the exact key (e.g., data) that holds your image binary data.

2. Avoid Accidental Removal of Binary Data

Sometimes nodes or transformations (like a Set node with “Keep Only Set”) might remove the binary property from your items. Double-check that your workflow isn’t inadvertently stripping away your binary data between nodes. You can do this by previewing the item right before the sending node.

3. Use the “Convert to File” Node If Needed

If your API or Dropbox expects file data in a different format or file path, consider adding a “Convert to File” node before sending. This node takes your binary data and writes it as a file, ensuring that the data is in the right format for your target service.

4. Check Node-Specific Options

Some integrations expect the file field to be referenced by its property name directly rather than through an expression. In such cases, configure the node by entering the binary property key (for example, data) into the appropriate parameter (like Input Data Field Name in some nodes) without wrapping it in expression syntax such as {{ ... }}.

Example Configuration for HTTP Request

If your binary data is stored in an item under a property called data, you can configure your HTTP Request node as follows:

JSONCopied
{
  "parameters": {
    "url": "https://your-api-endpoint.com/upload",
    "options": {
      "bodyType": "file"
    },
    "binaryPropertyName": "data"
  }
}

Summary

• Set the correct binary property name: Ensure that the sending nodes know which property contains the binary data.
• Keep binary data intact: Make sure that earlier nodes or transformations in your workflow aren’t stripping out the binary property.
• Use conversion nodes if applicable: If your target requires an actual file rather than raw binary data, use the “Convert to File” node.
• Avoid using expressions for field names: For nodes that require a field name (like some file uploads), enter the field name directly.

By checking these areas, you should be able to resolve the issue where the output item appears empty even though the images preview correctly.