D/D Dummy Data Lab
Runs locally · no upload

Build test data with full control

  1. 1Start
  2. 2Fields
  3. 3Relationships
  4. 4Export

One decision at a time.

Choose how you want to make this table.

Add your source tableChoose or paste a table

Your source stays in this tab—never uploaded or saved.

Input options

Start with a simple tableChoose how to start

Choose a template, then review or change its fields.Build everything locally from the fields you choose.

Project tablesThe tables stay linked automatically. Select one to review its fields.Template blocks and field edits apply to the selected table.
Select a stable unique column as this table's primary key.
New linked field

Choose generation settingsChoose the output size

Input size does not control output size.Choose a preset or enter an exact row count.

Output rows
Analyse a table to detect its data-row count.
Protection Safe Test Data Recommended protection is active. Switch to Advanced to change it.
Structure match

Analyse a table to see which useful structures can be retained.

Fine-tune structure matching
Changing a level resets these switches to that level's defaults.

Generate additional columns (optional)Define the columns to generate

New generated columns appear to the right of the transformed columns.These fields make up the complete generated table.

Quick covers common fields. Advanced adds dependencies, saved field sets, and detailed rules. Saved field sets contain definitions only—never your data.

Review each action

Compare a source sample with the preview. Open evidence and settings only when needed.

Keep all preserves source values; it is not anonymisation. High-risk KEEP values are highlighted for review.

Analyse a table to see column policies.

Add confirmed relationshipsConfirm and generateConfirm and generate

Only rules you confirm affect generation.

Advanced relationship rules remain off unless you enable them.

Test first when tuning ranges, weights, blanks, or uniqueness.

No analysis yet.
Not ready yetAnalyse a source table before generating.

Preview and export

Downloads include every generated row and column.

Generated data will appear here.