User import

There are two approaches for importing customer data into your Braze dashboard: REST API and CSV.


You can use Braze’s User Track REST API endpoint to record custom events, user attributes, and purchases for users. See User Track Endpoint for more information.


you can also upload and update user profiles via csv files from the user import page. this feature supports recording and updating user attributes such as first name and email, in addition to custom attributes such as shoe size. there are two different ways you can approach a csv import, depending on if your users have an external_id or not.

Import with external ID

When importing your customer data, you’ll need to specify each customer’s unique identifier, also known as external_id. Before starting your CSV import it’s important to understand from your engineering team how users will be identified in Braze. Typically this would be a database ID used internally. This should align with how users will be identified by the Braze SDK on mobile and web, and ensures that each customer will have a single user profile within Braze across their devices. Read more about Braze’s user profile lifecycle.

When you provide an external_id in your import, Braze will update any existing user with the same external_id or create a newly identified user with that external_id set if one is not found.

Download: CSV Import Template

Import with user alias

To target users who don’t have an external_id, you can import a list of users with user aliases. An alias serves as an alternative unique user identifier, and can be helpful if you are trying to market to anonymous users who haven’t signed up or made an account with your app.

If you are uploading or updating user profiles that are alias only, you must have the following two columns in your CSV:

  • user_alias_name: A unique user identifier; an alternative to the external_id.
  • user_alias_label: A common label by which to group user aliases.

User Alias Import CSV Example

When you provide both a user_alias_name and user_alias_label in your import, Braze will update any existing user with the same user_alias_name or create a newly identified user with that user_alias_name set if one is not found.

Download: CSV Alias Import Template

Constructing your CSV

Braze has several data types in Braze. When importing or updating user profiles via CSV, you can create or update default user attributes or custom attributes.

  • Default user attributes are reserved keys in Braze. For example, first_name or email.
  • Custom attributes are custom to your business. For example, a travel booking app may have a custom attribute called last_destination_searched.

Braze accepts user data in the standard CSV format from files up to 100MB in size. Refer to the sections above for CSV templates.

Data point considerations

Each piece of customer data imported via CSV will overwrite the existing value on user profiles and will count as a data point, except for external IDs and blank values.

  • External IDs uploaded via CSV will not consume data points. If you are uploading a CSV to segment existing Braze users by uploading only external IDs, this can be done without consuming data points. If you were to add additional data like user email or phone number in your import, that would overwrite existing user data, consuming your data points.
  • Blank values will not overwrite existing values on the user profile, and you do not need to include all existing user attributes in your CSV file.

Default user data column headers

external_id String A unique user identifier for your customer. Yes, see the following note
user_alias String A unique user identifier for anonymous users. An alternative to the external_id. No, see the following note
user_alias_label String A common label by which to group user aliases. Yes if user_alias is used
first_name String The first name of your users as they have indicated (e.g. Jane). No
last_name String The last name of your users as they have indicated (e.g. Doe). No
email String The email of your users as they have indicated (e.g. No
country String Country codes must be passed to Braze in the ISO-3166-1 alpha-2 standard (e.g. GB). No
dob String Must be passed in the format “YYYY-MM-DD” (e.g. 1980-12-21). This will import your user’s Date of Birth and enable you to target users whose birthday is “today”. No
gender String “M”, “F”, “O” (other), “N” (not applicable), “P” (prefer not to say), or nil (unknown). No
home_city String The home city of your users as they have indicated (e.g. London). No
language String Language must be passed to Braze in the ISO-639-1 standard (e.g. en).
List of accepted Languages
phone String A telephone number as indicated by your users, in E.164 format (e.g. +442071838750).
Refer to User Phone Numbers for formatting guidance.
email_open_tracking_disabled Boolean true or false accepted. Set to true to disable the open tracking pixel from being added to all future emails sent to this user. No
email_click_tracking_disabled Boolean true or false accepted. Set to true to disable the click tracking for all links within a future email, sent to this user. No
email_subscribe String Available values are opted_in (explicitly registered to receive email messages), unsubscribed (explicitly opted out of email messages), and subscribed (neither opted in nor out). No
push_subscribe String Available values are opted_in (explicitly registered to receive push messages), unsubscribed (explicitly opted out of push messages), and subscribed (neither opted in nor out). No
time_zone String Time zone must be passed to Braze in the same format as the IANA Time Zone Database (e.g. America/New_York or Eastern Time (US & Canada)). No

String May be passed in one of the following ISO8601 formats:
- “YYYY-MM-DDTHH:MM:SS” (e.g. 2019-11-20T18:38:57)
image_url String A URL of an image. No

Importing custom data via CSV

Any headers which do not exactly match default user data will create a custom attribute within Braze.

These data types are accepted in User Import:

  • Datetime (Must be stored in ISO-8601 format)
  • Boolean (TRUE/FALSE)
  • Number (Integer or Float with no spaces or commas, floats must use a period ‘.’ as the decimal separator)
  • String (no commas)
  • Blank (Blank values will not overwrite existing values on the user profile, and you do not need to include all existing user attributes in your CSV file.)

Importing a CSV

To import your CSV file, navigate to the User Import page under the Users section on the left-hand toolbar. In the lower text box, Recent Imports, there will be a table that lists up to twenty of your most recent imports, their file names, number of lines in the file, number of lines successfully imported, total lines in each file, and the status of each import.

The upper box, Import CSV, will contain importing directions and a button to begin your import. Click Select CSV File and select your file of interest, then click Start Upload. Braze will upload your file and check the column headers as well as the data types of each column.

To download a CSV template, refer to the sections Import with External ID or Import with User Alias on this page.

CSV Import

Once the upload is complete, you will see a modal window with a table previewing the contents of your file. All the information in this table is based on the values in the top few rows of your CSV file. For column headers, default attributes will be written in normal text, while custom attributes will be italicized and have their type noted in parentheses. There will also be a short summary of your file at the top of the pop-up.

You can import more than one CSV at the same time. CSV imports will run concurrently, and as such the order of updates is not guaranteed to be serial. If you require CSV imports to run one after another, you should wait until a CSV import has finished before uploading a second one.

If Braze notices something malformed in your file during the upload, errors will be shown above the summary. A file can be imported with errors, but an import cannot be canceled or rolled-back once started. Review the preview, and if you find any errors, cancel the import and modify your file. It’s important to examine the full CSV file before upload, as Braze doesn’t scan every row of the input file for the preview. This means errors can exist which Braze doesn’t catch while generating this preview.

Malformed rows and rows lacking an external ID will not be imported. All other errors can be imported, but may interfere with filtering when creating a segment.

CSV Import Errors

When you’re satisfied with the upload, start the import. The pop-up will close and the import will begin in the background. You can track its progress on the User Import page, which will refresh every 5 seconds, or at the press of the refresh button in the Recent Imports box.

Under Lines Processed, you will see the progress of the import; the status will change to Complete when finished. You can still use the rest of the Braze dashboard during the import, and you’ll receive notifications when the import begins and ends.

If the import process runs into an error, a yellow warning icon will be displayed next to the total number of lines in the file. You can hover over the icon to see details into why certain lines failed. Once the import is complete, all data will be added to existing profiles, or new profiles will be created.


user import creates and updates user profiles, and can also be used to create segments. to create a segment, check create a segment from this csv.

CSV Import Segmenting Users

You can set the name of the segment or accept the default, which is the name of your file. Files that were used to create a segment will have a link to view the segment once the import has been completed.

The filter used to create the segment selects users who were created or updated in a selected import and is available with all other filters in the edit segment page.

HTML data stripping

Braze does not sanitize HTML data during ingestion time. When importing data into Braze, specifically meant for personalization usage in a web browser, ensure that it is stripped of HTML, JavaScript, or any other script tag that potentially could be leveraged maliciously when rendered in a web browser.

Alternatively, for HTML, you can use Braze’s Liquid filters (strip_html) to HTML escape rendered text. For example:

{{ "Have <em>you</em> read <strong>Ulysses</strong>?" &#124; strip_html }}
Have you read Ulysses?


Malformed row

There must be a header row in order to properly import data. Each row must have the same number of cells as the header row. Rows whose length has more or fewer values than the header row will be excluded from the import. Commas in a value will be interpreted as a separator and can lead to this error being thrown. Additionally, all data must be UTF-8 encoded.

Multiple data types

Braze expects each value in a column to be of the same data type. Values that do not match their attribute’s data type will cause errors in segmenting.

Incorrectly formatted dates

Dates not in ISO-8601 format will not be read as datetimes on import.

String quotation

Values encapsulated in single (‘’) or double (“”) quotation marks will be read as strings on import.

Data imported as custom attribute

If you are seeing a piece of default user data (e.g. email or first_name) imported as a custom attribute, check the case and spacing of your CSV file. For example, First_name would be imported as a custom attribute, while first_name would be correctly imported into the “first name” field on a user’s profile.

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