What is the correct format for a CSV file to create a segment with user IDs in Pushwoosh?

To create a segment from a list of User IDs, upload a CSV in Audience → Segments → Create Segment → Import segment.

File requirements

• One column holding the identifiers — either User IDs or Hardware IDs (HWIDs) — that are already registered in your project. Identifiers that are not registered are skipped, and a file with no valid identifier produces no segment.
• Comma-delimited CSV saved in UTF-8, smaller than 100 MB.
• A header row is recommended, since you pick the identifier column by name during mapping.

Import steps

1. Upload the file, then on the Preparing for import step enter a Segment name.
2. Under CSV column with identifiers, select the column that holds your values.
3. Under System identifier, choose User ID (or Hardware ID (HWID)) so Pushwoosh knows how to match them. Mapping a column of User IDs to HWID is the most common reason rows are skipped.
4. Click Import. Processing may take a while; the segment then appears in the Segments list, and every imported user is tagged with a CSV import tag holding the import timestamp.

About User IDs

By default Pushwoosh sets the User ID equal to the device’s HWID, so each device counts as a separate user. A custom User ID is assigned by your app through the setUserId SDK method (for example Pushwoosh.getInstance().setUserId("testUser") on Android, [[Pushwoosh sharedInstance] setUserId:@"userId"] on iOS); the corresponding server-side Device API method is /registerUser. There is no /setUserId endpoint. Up to 20 devices can be linked to one User ID — beyond that the oldest inactive device is removed automatically.

See Users (User IDs), Collecting User IDs and Import a segment.