Marketing Channels Data Upgrade (API)

This article outlines the upgrade to Similarweb’s Marketing Channels data in the API, AI Studio, MCP and other forms of reporting, including what’s changing, key timelines, and required actions.

Overview

Similarweb has introduced an upgraded Marketing Channels dataset, designed to improve channels attribution, data granularity, and more. This upgrade is already available in the Pro platform since April 2026, and will be rolled out to both Batch and REST APIs in phases.

What’s Improved In The Data

The new dataset includes several enhancements:

• Expanded channel coverage: We’ve added new channels: Gen AI, Affiliates, Paid Social, and Organic Social
• Increased Granularity: View the Marketing Channels by Daily, weekly, and monthly data (available in the platform, Rest API, and MCP)
• Improved trend detection: Improved identification of traffic spikes, drops, and shifts
• Statistically improved channel attribution
• To support the change, 37 months of recalculated data for year-over-year analysis will be conducted to ensure consistency in your analysis.

Phased, side-by-side transition to new datasets & end-points

Batch API Migration

At the end of a 6-month overlap period during which both datasets will be accessible, the old dataset is fully deprecated. Customers with access to the Data exporter will follow the same timeline.
 

Timeline

• May 31, 2026 – New dataset is released, starting a 6-months transition period with side by side experience, having access to the legacy and the new Dataset.
• November 30, 2026 – Legacy datasets fully deprecated

May 31, 2026: Required Action

On May 31, new Marketing Channels dataset will be introduced:

website_marketing_channels

To avoid disruption, you must take one of the following actions:

Option 1: Temporarily stay on current data

Add the following parameter to your Batch API requests:

"data_version": "VERSION_5.0"

• By adding this parameter, you can continue getting the previous data version.
• Recommended only for short-term continuity

Note - If you use the referrals vtable, please add the parameter data_version: "VERSION_5.0" to your request body according to the example below. Otherwise, your request will fail.

API Example Query with the Old Data Version

Here's an example of how to incorporate the previous MMX data into your Batch API query:

POST https://api.similarweb.com/batch/v4/request-report

curl --location 'https://api.similarweb.com/batch/v4/request-report' \

--header 'api-key: {{API_KEY}}' \

--header 'Content-Type: application/json' \

--data '{

"delivery_information": {

  "response_format": "csv"

},

"report_query": {

  "tables": [

    {

      "vtable": "marketing_channels",

      "granularity": "monthly",

      "filters": {

        "domains": [

          "similarweb.com",

          "amazon.com"

        ],

        "countries": [

          "WW",

          "GB",

          "US"

        ],

        "include_subdomains": true

      },

      "metrics": [

        "desktop_marketing_channels_visits",

        "desktop_marketing_channels_share",

        "mobile_marketing_channels_visits",

        "mobile_marketing_channels_share"

      ],

      "start_date": "2026-01",

      "end_date": "2026-03",

      "data_version": "VERSION_5.0"

    }

  ]

},

"report_name": "old data version "

}

Example #2 - traffic & engagement 

 

POST https://api.similarweb.com/batch/v4/request-report

curl --location 'https://api.similarweb.com/batch/v4/request-report' \

--header 'api-key: {{API_KEY}}' \

--header 'Content-Type: application/json' \

--data '{

"delivery_information": {

 "response_format": "csv"

},

"report_query": {

 "tables": [

   {

     "vtable": "traffic_and_engagement",

     "granularity": "monthly",

     "filters": {

       "domains": [

         "similarweb.com",

         "amazon.com"

       ],

       "countries": [

         "US"

       ],

       "include_subdomains": true

     },

     "metrics": [

       "referrals_channel_desktop_share",

       "referrals_channel_desktop_visits",

       "direct_channel_desktop_share",

       "direct_channel_desktop_visits"

     ],

     "start_date": "2025-12",

     "end_date": "2026-02",

"data_version": "VERSION_5.0"

   }

 ]

},

"report_name": "old data version report "

}

Option 2: Migrate to the new dataset (recommended)

Update your queries to use:

website_marketing_channels vtable

Available metrics: 
marketing_channels_total_visits

marketing_channels_total_share

marketing_channels_desktop_visits

marketing_channels_desktop_share

marketing_channels_mobile_visits

marketing_channels_mobile_share

• Provides access to the upgraded dataset starting May 31
• Enables improved coverage, accuracy, and historical data

If no action is taken, requests to deprecated datasets will fail after May 31.

Your experience starting 31 May, 2026

• The website_marketing_channels vtable becomes the primary dataset
• It includes full coverage equivalent to legacy datasets

Device Coverage

• Desktop and Mobile Web splits remain available
• New All Traffic endpoints provide a unified cross-device view

Final Dataset Replacement (After November 30, 2026)

Legacy datasets will be replaced with the following metrics:

• Marketing_channels_total_visits
• Marketing_channels_total_share
• Marketing_channels_desktop_visits
• Marketing_channels_desktop_share
• Marketing_channels_mobile_visits
• Marketing_channels_mobile_share

Recap: Key changes to Batch API

1. BATCH API Changes: New metrics and dataset available from June 1st, replacing the deprecated endpoints (on the next slide)

2. BATCH API Changes: List of “old” metrics that will be deprecated at the end of the transitions period (replaced by the new data on the previous slide)]
 

3. BATCH API Changes: Updated metrics, available from end of May (No deprecation), side by side transition will be available

4. BATCH API Changes: 

Marketing Channels Beta metrics, deprecated on 25 April.

This will result in a temporary gap between 25 April and 31 May for these metrics. 

REST API Migration

By the end of June 2026, customers will have a 3-month transition period starting once all new endpoints are available (end of June 2026). During this time, both the new and the old endpoints will be accessible. The old endpoints are expected to be deprecated by September 30th, 2026, at the end of the 3-month side-by-side transition period.

Customers with access to AI Studio and MCP will follow the same timeline, with a small delay.

Timeline

• June 31 2026 – New endpoints released
• 3 months side-by-side with the legacy and new endpoints begin 
• September 30, 2026 – Legacy endpoints fully deprecated

What to Expect

• New REST endpoints will include the upgraded Marketing Channels data
• Existing endpoints will remain available for 3 months
• Migration can be completed at any point during this window

For further assistance, contact your Customer Success Manager.