SynthForge SynthForge SynthForge IO

Comparison · Verified September 2026

Looking for a Neosync alternative?

Neosync did two jobs: it anonymized real production data, and it generated synthetic data. It is no longer maintained. SynthForge does one of those two jobs, and this page is clear about which.

TL;DR

Neosync was acquired by Grow Therapy, announced in September 2025, and its GitHub repository now says it is no longer actively maintained. If you used Neosync to mask or subset real production data, Greenmask is the closer successor and SynthForge is not a substitute: SynthForge never reads production data. If you used Neosync to get realistic relational test data without touching production at all, SynthForge is the closer match. Design the schema, generate every table in one pass with foreign keys intact, and download ready-to-load files.

Recent context

Grow Therapy announced the acquisition on 2025-09-25, describing Neosync as a company specializing in data privacy and security. The nucleuscloud/neosync repository (MIT, about 4,100 stars) opens with a disclaimer that Neosync has been acquired and the repository is no longer actively maintained, and it is archived; its last commit is dated 2025-08-30. As of September 2026, neosync.dev returns a 404 and app.neosync.dev and docs.neosync.dev no longer resolve. The code and its Docker Compose file are still in the archived repository, but nothing in it will be updated.

When Neosync, or an anonymization tool, is the right call

  • You need to anonymize or mask a real production database before copying it to staging or sharing it. That was Neosync's core job, and SynthForge cannot do it. Greenmask is an actively maintained open-source database anonymizer built for exactly this.
  • You need to subset a large production database into a smaller slice that keeps its relationships. Neosync did this; SynthForge does not.
  • You need data moved between environments through direct database connections. Neosync connected to Postgres, MySQL, SQL Server, MongoDB, DynamoDB and S3. SynthForge produces files and load scripts that you run yourself.
  • You need everything to run on your own infrastructure. SynthForge is cloud-only.

When SynthForge is the right call

  • You used Neosync's synthetic data generation to fill dev, CI or demo databases, and production data was never part of it. SynthForge generates every table in one pass, and every foreign key points at a parent row that exists.
  • You would rather not run and patch test data infrastructure yourself. SynthForge is a hosted web app with an API, a TypeScript SDK and a hosted MCP server.
  • You need ready-to-load output for several databases: DDL, CSV files and a native bulk-load script for PostgreSQL, MySQL, SQLite, SQL Server, MariaDB, DuckDB and CockroachDB, plus JSON, JSONL and Parquet.
  • You want to start from a plain-English description or pasted CREATE TABLE statements, and set how many children each parent gets as a ratio instead of a fixed count.
  • You want to start without a contract: the first 20,000 rows of every dataset are free, and larger runs use credits.

Feature comparison

Verified against primary sources in September 2026.

Feature SynthForge Neosync
Product status (September 2026) Live and hosted Acquired by Grow Therapy. Repository archived and no longer maintained.
Reads production data No, never Yes. Anonymization and subsetting work on real source databases.
Anonymization / masking No Yes, with built-in transformers and custom ones in JavaScript or via an LLM
Subsetting No Yes, with referential integrity
Synthetic data generation Yes, from a schema, across related tables in one pass Yes
Foreign key integrity Yes (single-column, by construction) Yes
Database connections None. You download files and load them. Postgres, MySQL, SQL Server, MongoDB, DynamoDB, S3
Output DDL, CSV and a bulk-load script for 7 SQL dialects, plus JSON, JSONL and Parquet Data written into connected destinations
Deployment Hosted, cloud only Self-hosted (Docker Compose or Kubernetes). The hosted app no longer resolves.
License Proprietary, not open source MIT

Pricing comparison

SynthForge

Free $0

All features. The first 20,000 rows of every dataset are free, no credit card. 10,000,000 rows per table, and a 1 GB cap on the download.

Credits from $5

500 credits for $5. About 12 datasets of 1,000,000 rows, or many more at typical sizes.

Neosync

Neosync open source $0 (MIT)

Archived and no longer maintained. You run it, and you patch it.

Neosync hosted Offline

neosync.dev returns a 404 and app.neosync.dev no longer resolves, as of September 2026.

What SynthForge does not do that Neosync does

Honest tradeoffs, in case they decide the comparison for you.

  • SynthForge does not anonymize, mask or subset real data. If that was your Neosync use case, SynthForge is the wrong tool; look at Greenmask.
  • SynthForge does not connect to your databases or sync data between environments. It produces files and load scripts.
  • SynthForge is cloud-only and not open source. Neosync's code is MIT-licensed and still on GitHub, even though it is archived.
  • There is no way to import Neosync job definitions or transformers. You recreate the schema in SynthForge.

Frequently asked questions

Is Neosync still maintained?
No. Grow Therapy announced its acquisition of Neosync on 2025-09-25. The nucleuscloud/neosync repository is archived and opens with a notice that it is no longer actively maintained; its last commit is dated 2025-08-30. As of September 2026, neosync.dev returns a 404.
What is the best Neosync alternative?
It depends on which half of Neosync you used. For anonymizing or subsetting production databases, Greenmask is an actively maintained open-source tool built for that job. For generating realistic relational test data from a schema, with no production data involved, SynthForge is the closer fit.
Can I import my Neosync jobs into SynthForge?
No. There is no migration path for Neosync job definitions or transformers. Recreate the schema in SynthForge by pasting your CREATE TABLE statements, describing it in plain English, or building it in the editor, then pick generators for each column.
Does SynthForge keep foreign keys consistent?
Yes, for the data it generates. Parent tables are generated first, and every child foreign key is drawn from parent IDs that exist. Single-column foreign keys are supported; composite and self-referential foreign keys are not.
How much does SynthForge cost?
The first 20,000 rows of every dataset are free, with no credit card. Larger runs use credits, from $5 for 500.
Sources used to verify these claims

Other SynthForge comparisons

Try it on your next multi-table schema

Free for the first 20,000 rows, no credit card.