Should You Keep or Migrate Your Power BI Dataflow in 2026?

The Problem We Are Solving

Maybe you inherited a Power BI dataflow that still refreshes every morning. Reports depend on it, nobody has mapped all the connections, and now Microsoft calls Dataflow Gen1 “legacy”.

That word makes the situation sound more urgent than it is.

Legacy means Gen1 is no longer receiving new feature investment. It does not mean every working Gen1 dataflow must be replaced immediately. Microsoft says existing Gen1 workloads can continue to run, and Pro or Premium Per User customers can continue using Gen1 while its guidance for those scenarios evolves.

The useful decision is not “Is Gen2 newer?” It is:

Should we keep this Gen1 dataflow, test Gen2 alongside it, or plan a controlled migration?

The Short Answer

Do not migrate a working dataflow only because it has acquired a legacy label.

• Keep it for now when it is stable, understood and still fits your licensing.
• Test Gen2 separately when you have Fabric access and want to learn how the same queries behave without disturbing a live report.
• Plan a migration when the dataflow is changing, you need Gen2 capabilities, or the existing workflow is becoming harder to support.

Whichever route you choose, inventory the reports, semantic models, Excel files and other dataflows that depend on the current item before you touch it. Microsoft puts that inventory step first in its migration guidance for a reason: copying the Power Query logic is usually easier than finding everything that will be affected afterwards.

Choose Your Route

First, Make a One-Page Inventory

You do not need an enterprise architecture exercise. You need enough information to avoid breaking the monthly report.

Copy this table into Excel or a work note and complete one row for each dataflow:

If you cannot identify the owner or downstream use, that is not a reason to migrate faster. It is the first risk to fix.

Confirm That You Can Test Gen2

For the documented Save as Dataflow Gen2 migration route, Microsoft lists three prerequisites:

1. The target workspace must use Fabric capacity of F2 or higher, or a Fabric trial.
2. The tenant setting Users can create Fabric items must be enabled for you or your group.
3. You need the Contributor workspace role or higher in the target workspace.

Power BI Pro and PPU workspaces on their own do not support Dataflow Gen2.

If you do not know the answers, send this to your Fabric or Power BI administrator:

Pick the Least Disruptive Migration Method

Microsoft documents three ways to move Gen1 queries into Gen2:

• export the Gen1 queries as a Power Query template and import them
• copy and paste the queries in Power Query
• use Save as Dataflow Gen2 to create a new Gen2 item

For an inherited dataflow, Save As is a useful starting point because it creates a separate Gen2 item that you can review. It is not a complete cutover.

Two settings need particular attention:

• Scheduled refresh settings are not copied by Save As.
• Incremental-refresh settings are not copied when saving a Gen1 dataflow as Gen2.

Treat the new item as an untested replacement until you have recreated the required settings and checked every downstream connection.

Test Before You Switch Anything

A successful refresh only proves that the new dataflow ran. It does not prove that the business report is still right.

Before moving a report or semantic model to Gen2, check:

• every expected query is present
• source credentials and gateway access work
• the refresh completes at an acceptable time
• row counts are within the expected range
• important dates, IDs and null values still behave correctly
• the totals and KPIs people challenge in meetings match the approved baseline
• scheduled and incremental-refresh behaviour has been recreated where needed
• a test report or semantic model can consume the new output
• the original Gen1 item can remain available until the replacement has passed an agreed test period

Move consumers in controlled groups. Start with a test report, not the report used in tomorrow morning’s leadership meeting.

Watch the Destination Settings

Gen2 can send each query to a destination such as a Fabric Lakehouse, Warehouse or another supported store. That flexibility introduces a setting worth checking carefully.

For new Lakehouse and Azure SQL destination tables, automatic settings use replace behaviour and can drop and recreate the table during refresh. Microsoft warns that this might remove relationships or measures previously added to that table.

If a downstream semantic model depends on relationships or measures attached to the destination table, review the destination and schema settings before the first production refresh. Microsoft documents fixed-schema settings as the option that keeps existing relationships and measures intact, although a refresh or publish will fail when the query schema no longer matches. That is a trade-off to test, not a switch to change blindly.

What Still Transfers From the Original Session

The useful Power Query work has not become obsolete.

Microsoft’s supported migration methods are based on moving or reusing the existing queries. Your transformations may transfer, but the surrounding operating setup still needs attention: capacity, permissions, schedules, incremental refresh, destinations and downstream consumers.

That is the practical 2026 update:

Keep the working logic where it is safe, test Gen2 where it is useful, and migrate only after you know what depends on the current dataflow.

Evidence Notes

Microsoft documentation supports these decisions:

• Gen1 is supported but in a legacy state and is not receiving new feature investment. Existing workloads can continue while teams plan their transition.
• Pro and PPU customers can continue using Gen1. Gen2 requires an appropriate capacity-backed workspace or trial.
• Microsoft recommends taking an inventory of dataflows and dependent items before migration.
• Microsoft documents Power Query template, copy-and-paste and Save As migration routes.
• Save As does not copy scheduled-refresh or Gen1 incremental-refresh settings.
• Automatic destination settings can drop and recreate some destination tables, which may remove relationships or measures.

The documentation does not prove that your migration will preserve business totals, run at the same cost, finish in the same time, or leave every downstream report untouched. Only a side-by-side test against your own sources, refresh pattern and agreed KPIs can establish that.

Your Next Move

Choose one important Gen1 dataflow and complete the inventory table before anyone changes it.

At the end of that check, record one decision:

• Keep Gen1 and review again on a named date
• Run a side-by-side Gen2 test
• Plan migration with an owner, test period and rollback route

If you cannot yet name the downstream consumers or the person responsible for the change, the decision is inventory first.