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data variety
generates uuids, emails, names, addresses, and phone numbers. covers standard database fields.
dev utility
randumb.
generate structured random data for testing.
randumb creates realistic mock data for your applications. it generates standard formats like uuids, emails, phone numbers, and names in bulk.
what it is
randumb is a test data generator available as a cli and web tool. it produces realistic, formatted data including names, addresses, emails, and primary keys. you can request specific schemas and output formats like csv or json.
manually typing test data into your forms or writing custom scripts to populate a staging database is tedious. production data should never be used for local testing due to privacy laws. randumb generates safe, structural equivalents in milliseconds.
frontend developers use it to populate ui mockups, and backend engineers use it to stress-test database queries. it generates data without exhausting system memory.
core features
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bulk generation
create thousands of records in milliseconds. optimized for speed and low memory usage.
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multiple formats
output data as csv, json, or sql insert statements. ready to be loaded into your database.
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deterministic seeds
supply a seed value to generate the exact same fake data every time. useful for reproducible tests.
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cli and web
use the web interface for quick mockups or the cli for automated database seeding scripts.
how to use it
generate five random user records in json format.
// input
randumb generate users --count 5 --format json
// output
[{"id": "a1b2", "name": "alice", "email": "alice@example.com"},
{"id": "c3d4", "name": "bob", "email": "bob@example.com"}]
it generated structured mock data without querying a real database.
why we built it
using real user data in local development environments is a massive security risk and usually illegal. but testing a complex ui with the word 'test' in every field makes it impossible to spot layout bugs.
we built randumb because existing fake data generators were bloated. we just wanted a standard cli command that spits out a thousand valid email addresses instantly.
frequently asked questions
can i define a custom schema?
yes. you can pass a json schema file to the cli, and it will generate records that match your specific fields.
are the generated emails valid?
they are structurally valid but use standard example domains. they will pass regex checks but will not deliver actual mail.
how fast is the cli?
it can generate about a hundred thousand basic records per second on a modern machine.
does it generate relational data?
no. it generates flat records. if you need foreign key relationships, you will have to map them yourself.
// stop using production data on your laptop.