Gretel.ai vs LocalStack
Feature checklists rarely decide anything. What decides it is the pricing metric, who has to write the tests, and which limitation you can live with.
Entry price
Quote on request
Quote onlyFrom $39 per licence/month (Base, billed annually; $45 monthly)
Free tierWhat drives the bill
The metric that actually scales your invoice.
The old credit-based self-serve tier is gone. The successor microservices are licensed through NVIDIA AI Enterprise; NeMo Data Designer can be tried on build.nvidia.com.
Plans are Hobby (free, non-commercial), Base $39 and Ultimate $89 per licence/month billed annually, then Enterprise. Commercial use needs a paid licence, and the higher tiers are what unlock advanced IAM enforcement and the wider service coverage.
Free tier
Hobby tier is free but explicitly non-commercial, and LocalStack has said the Community emulator will no longer receive product updates.
Open source
Self-hostable
No-code authoring
Languages
Platforms
Fits teams
Adoption
Emerging
NVIDIA (formerly Gretel) · since 2019
Category standard
LocalStack · since 2017
Strengths
- Formal differential-privacy guarantees rather than best-effort masking, now via DP-SGD in NeMo Safe Synthesizer.
- Synthetic data preserves statistical relationships useful for analytics and model training.
- Backed by NVIDIA's platform investment rather than a single startup's runway.
- Integration tests against AWS services run offline in seconds at no cloud cost.
- Removes the shared-sandbox-account contention that plagues cloud teams.
- Works with Terraform and CDK, so infrastructure code is testable.
Limitations
- No longer buyable as Gretel — you are procuring NVIDIA AI Enterprise, which is far heavier than the old self-serve signup.
- Model training adds time and cost compared to rule-based masking.
- Safe Synthesizer trains on a real dataset, so it does not help with greenfield data that does not exist yet.
- No longer open source: the Community edition is end-of-life, the repo is archived, and running it now requires an account and auth token.
- Using it in CI counts as commercial use, so the free tier does not cover the case most teams want it for.
- Emulation is not identical to AWS; some behaviours and IAM semantics differ.
Best for
Regulated enterprises already standardising on NVIDIA AI Enterprise. Teams that wanted Gretel's self-serve tier should look at Tonic or Neosync instead.
AWS-native teams whose tests currently depend on a shared cloud account, and who are willing to pay for a licence now that the free community route has closed.
Pricing last reviewed August 2026 and is indicative only — confirm on each vendor’s own page.