Synthetic data for research labs and data teams

Synthetic data that behaves like the real thing

Ground is a synthetic data generator for research labs and data teams. Describe a dataset or extend one you already have. Review 25 sample rows, refine, then export realistic data as CSV, JSON Lines or Parquet.

Ground's Contour mark, sculpted in terracotta ceramic
Drag horizontally to turn the sculpture. With a mouse, drag vertically to tilt. You can also use the arrow keys to rotate and Home to replay. Vertical touch gestures scroll the page.
Card transactions
Previewing 25 of 1,000,000 rows
#timestampamount_usdmerchantmerchant_categorychannelstateis_fraud
12025-04-09T17:36:34Z754.65Crona Groupgrocerycard_presentMIfalse
22025-02-21T00:07:47Z713.67Anderson-Lubowitz, Nolan and AufderharelectronicsonlineCAfalse
32025-06-19T12:14:40Z531.94Prohaska, Quigley and Abernathyothercard_presentPAfalse
42025-03-13T18:53:16Z4000.00Reichert - Watsicaonline_retailcard_presentNCfalse
52025-06-01T09:39:15Z173.39Stroman, Raynor and Vandervortonline_retailonlineNYfalse
62025-02-05T10:15:44Z128.14Kreiger - Keelinggrocerycard_presentWAfalse
72025-02-27T09:26:54Z4000.00Weissnat - Sawaynrestaurantscard_presentMNfalse
82025-04-09T12:21:04Z924.49Grant, Conn and LarkinotheronlineILfalse
92025-01-26T04:50:48Z925.61Ryan Grouponline_retailonlineFLfalse

For teams who can't wait for, can't share or can't collect the real data

Start with the job you need to do

See it before you generate it

1

Describe it

Write your request in plain English: what each row is, the label rates you need, the quirks of the real data. Ground designs every column.

5,000 ICU admissions with diagnosis codes, length of stay and a short admission note. About 8% of vitals missing.
Design dataset
2

Review 25 rows, then refine

Edit the request or click any cell to say what's off. The preview updates, and every revision can be undone.

Row 4 · admission_note

“Patient presents with chest pain…”

Too polished. Real notes use abbreviations.
“58M c/o CP x3d, SOB on exertion. Hx HTN…”
3

Generate at size

Up to 10 million rows run in the background. Your file starts with the exact rows you approved, and you download it as CSV or JSON Lines.

icu_admissions.csv5,000 rows

72%

Measured, not claimed

93/100 on six public datasets

Every method trains on the same 80% of each table and is scored on the same unseen 20%: column shapes, relationships and a classifier trying to tell real from synthetic. MOSTLY AI averages 83 and SDV 66.

Every number, method and caveat
Ground MOSTLY AI (open-source engine) SDV (best of two)
adult
94
95
67
bank
90
65
60
credit
91
79
63
telco
92
90
65
housing
95
93
60
insurance
98
77
82

Overall score, 0–100, from Ground's own report; independent scoring is on our roadmap. MOSTLY AI wins on adult; differences of a point or two are within noise.

Extend your data

Already have data? Get more of it.

Upload a CSV or Parquet file. Ground learns each column and how the columns relate, per class of your label, then generates new rows: more of the same, more of a rare class or segment, or the months after your data ends.

Extend a dataset
Spot the synthetic

Ten real rows, ten generated, shuffled. If you can't tell them apart, neither can a reviewer.

Fix the gaps

Raise a 3% label to 25%, add rows for a thin segment, or extend six months forward, in one click.

Privacy controls you can review

Detected personal data is replaced, rare record copies are checked, and the report measures remaining privacy risk.

A report you can cite

Fidelity, a real-vs-synthetic classifier test, train-on-synthetic results and privacy metrics, as a shareable data card.

Realistic enough to train on

Coherent rows

Names, emails, employers and locations agree within each row, and AI-written text matches the values next to it.

Real-world mess

Long tails, skewed categories, rare labels at believable rates and missing values where real systems have gaps.

Reproducible

Every dataset is a saved spec and a seed. Regenerate the same rows next quarter, or draw a fresh sample.

Built for size

Up to 10 million rows per dataset, generated in the background and streamed straight to a file.

Every column your data needs

Mix rule-based columns, which are fast and free, with AI columns for text that has to make sense.

Realistic value

Names, emails, companies and places that agree with each other in every row.

Whole number

Whole numbers in a range.

Decimal number

Uniform, normal or long-tailed distributions for prices, scores and revenue.

True / false

Flags with the exact rate you need, down to rare 2% fraud labels.

Category

Weighted values, so your plan mix and order statuses look real.

Date

Dates and timestamps across any window.

UUID

Unique identifiers, stable for a given seed.

Sequence / ID

Readable IDs like ORD-100231.

Formula

Formulas built from other columns, like emails from names.

AI text

Free text written by Claude that matches the rest of the row.

Start from a template

Put synthetic data to work

Practical guides for your first dataset, testing pipelines, training models and checking the results.

Your next dataset is one sentence away

Start building for free