# Data & Dimension Validation
URL: https://docs.valsight.ai/data-dimension-validation/
Description: Validate that uploaded data is correctly formatted, contains expected values, and complies with your defined dimensions.
Validate that uploaded data is **correctly formatted**, contains **expected values**, and complies with your **defined dimensions**.

## How it works

The validation function checks uploaded base data against the project's dimension definitions. It verifies that:

* Data is correctly formatted
* Values fall within expected ranges
* Level values match the defined dimensions

If deviations are found, the validation tool reports the kind of error and its exact location.

## Steps

### Validating uploaded data

1. Open the **Data Source** page for the file you want to validate.
2. Click **Validate Dimensions**.

The validation results appear inline, listing any issues with their location and type.

![image-20260402-090717.png](./images/6861651970.png)

### Impact check when changing data sources

When you rename or delete a data source, Valsight automatically validates the impact on existing nodes. If the change would invalidate any nodes, a list of affected nodes is displayed for review before the action is finalized.

1. Initiate a rename or delete action on a data source.
2. Review the list of affected nodes that Valsight displays.
3. If the invalidations are acceptable, confirm the action by clicking **Rename** or **Delete**.

![image-20260402-090531.png](./images/6861357073.png)

## FAQ

**What does data validation check?**

It checks that uploaded data complies with your dimension definitions, is correctly formatted, and contains no unexpected values.

**Do I need to validate every time I upload?**

It is recommended after any data upload or dimension change to catch issues early.

**What happens if validation finds issues?**

The validation report lists each issue with its location. You can then fix the problems in your source data and re-upload.

## Related

* [Model Validation](/model-validation/): verify model formulas and node compatibility
* [Workspace Validation](/workspace-validation/): check workspace scenarios