PBIR becomes the default Power BI report format: what to check before it reaches you

The way Power BI stores a report is changing under your feet. The January 2026 Power BI feature summary confirms that the enhanced report format, PBIR, is now being switched on by default in the Power BI service as a phased rollout, with full availability expected by the end of February. From the March release, Power BI Desktop will save reports as PBIR by default too.

Most report authors will never notice. Teams that keep reports in Git, run deployment scripts or have tooling that reads report.json will, so spend an hour on this now rather than after the first strange diff lands in a pull request.

What PBIR actually is

Until now, the report part of a Power BI file has been stored in a format Microsoft calls PBIR-Legacy: one large report.json file. It is not publicly documented and does not support external editing.

PBIR replaces that file with a definition folder. Each page, visual and bookmark gets its own JSON file, and every file has a public JSON schema. Code editors like Visual Studio Code can use those schemas for validation and IntelliSense while you edit.

The practical gains Microsoft lists are the ones you would expect from a text format:

• Copy pages, visuals or bookmarks between reports.
• Find and replace across many report files at once.
• Apply a batch edit to all visuals with a script.
• Get readable diffs and fewer painful merge conflicts.

What changes, and when

The timeline from the official announcement and the January update:

1. In the Power BI service, new reports are created as PBIR by default, rolling out in phases through the end of February.
2. Existing service reports are converted to PBIR automatically when they are edited and saved.
3. From the March 2026 Desktop release, PBIR becomes the default for both PBIX and PBIP files.
4. General availability is planned for Q3 2026. At GA, PBIR becomes the only supported report format and PBIR-Legacy is no longer supported.

PBIR is still in preview during this period, which is why there is an opt-out. Microsoft is clear that defaulting to PBIR is the last step before GA, so the opt-out buys time, not a permanent exemption.

If you only use PBIX files

Microsoft says PBIX remains the primary file format, and for PBIX users the switch is silent. What changes is how the report is stored inside the PBIX: PBIR instead of PBIR-Legacy. That brings PBIX and PBIP to parity for report metadata.

So if your team publishes PBIX files from Desktop and never looks inside them, there is very little to do. The exception is any homegrown tool or script that unzips a PBIX and parses report.json. That code will break once reports are converted.

If you use PBIP and Git

This is where the change is most visible. A few things from the documentation are worth knowing before your first converted report is committed:

• The first commit after conversion is big. report.json disappears and a definition folder with many small files appears. Agree on who converts which report, so two people do not convert the same one on separate branches.
• Check definition.pbir. The version property controls the supported formats. Version 1.0 only allows PBIR-Legacy. Version 4.0 or higher allows PBIR.
• File names are IDs. By default, page, visual and bookmark folders are named after the object name, initially a 20 character unique identifier. You can rename them to something friendlier, but renaming the name property can break references, and you must restart Desktop afterwards.
• Data values can end up in metadata. Files such as visual.json or bookmarks.json can store values from your semantic model, for example a filter on 'Company' = 'Contoso' or slicer selections. If your repository is shared more widely than the data, review this.
• External edits must follow the schema. Invalid schemas or missing required properties are blocking errors in Desktop. Validate in VS Code before you open the project.

The upside is real. Once the definition folder is in Git, a pull request shows that someone moved one visual, not that a huge JSON blob changed.

What admins should check

The service behaviour is controlled by a tenant setting under Workspace settings: "Automatically convert and store reports using Power BI enhanced metadata format (PBIR) (preview)". With it on, edited reports are converted to PBIR when saved, and new reports are created as PBIR.

The setting is on by default. If you opt out, PBIR in the service stays off until general availability. In Desktop, the opt-out is the preview features "Store reports using enhanced metadata format (PBIR)" and "Store PBIX reports using enhanced metadata format (PBIR)".

My advice is not to opt out by reflex. Opt out only if you have a concrete blocker, write down what it is, and plan to remove it before Q3.

What to do next

A short checklist for the next few weeks:

1. Decide as a team whether you keep the tenant setting on. If you turn it off, record why.
2. Search your scripts, pipelines and tools for anything that reads report.json, and plan the rewrite against the PBIR schemas.
3. Pick one report in a PBIP repository, convert it on purpose, and review the commit together.
4. Agree on naming: keep the generated IDs, or rename folders with a script and accept the restart.
5. Check whether filter and slicer values in report metadata are acceptable in your repository.
6. Update internal documentation and onboarding notes that describe report.json.

Takeaway

After two decades in data, I am glad to see the report layer finally become something you can read, diff and script. The change itself is quiet for most people, but GA will remove the choice, so the teams that test it now will have the easiest year.

Have you converted a report to PBIR yet, and what was the first thing in your pipeline that broke?

Sources

• Power BI January 2026 Feature Summary (Power BI blog)
• PBIR will become the default Power BI Report Format: Get Ready for the Transition (Power BI blog)
• Power BI Desktop project report folder (Microsoft Learn)
• Workspace tenant settings (Microsoft Learn)