SDV (Synthetic Data Vault) alternatives: 5 tools compared (October 2026)

Appen supplies training and evaluation data for AI models, from RLHF and red teaming to speech, multimodal and LiDAR annotation, for AI developers and large enterprises.

Key functions

• RLHF, reasoning traces and red teaming for model builders
• Annotation for speech (ASR, TTS), vision-language data and LiDAR
• ADAP platform combines automation with human review

Compared with SDV (Synthetic Data Vault)

• Built for larger organizations than SDV (Synthetic Data Vault)'s smallest customers.
• Names 2 security certificates, SDV (Synthetic Data Vault) 0.
• Strongest elsewhere: Australia.

Check before buying: Appen publishes no prices, so define volume, languages and quality targets for a quote. Clarify where data is stored and which contributors in which countries will see it. Request a data processing agreement and the security documentation before sharing personal data such as voice recordings.

MOSTLY AI generates synthetic versions of sensitive tabular data, so banks, insurers and other companies can share, test and analyze data without exposing real personal records.

Key functions

• Generative models (TabularARGN) create synthetic tabular and text data
• Differential privacy as a training option
• AI assistant writes Python code and analyzes data from natural language prompts

Compared with SDV (Synthetic Data Vault)

• Built for larger organizations than SDV (Synthetic Data Vault)'s smallest customers.
• Strongest elsewhere: Austria.

Check before buying: Since Syntho acquired the MOSTLY AI brand in June 2026, ask which company is your contracting partner and how support and the platform roadmap continue. Decide whether the open-source SDK in your own environment is enough or whether you need the platform, whose prices are only available on request. Have your data protection officer assess whether the synthetic output counts as anonymous for your use case. When real employee data is used as input, check co-determination and data processing terms.

Syntho produces synthetic test data for software development, testing and analytics, combining AI-generated data, rule-based generation and masking so companies can work with production-like data without exposing real records.

Key functions

• AI-generated synthetic data reproduces statistical patterns of real data
• Sensitivity scanner finds protected fields in databases
• Quality reports compare synthetic and original data

Compared with SDV (Synthetic Data Vault)

• Built for larger organizations than SDV (Synthetic Data Vault)'s smallest customers.
• Strongest elsewhere: Netherlands.

Check before buying: Syntho is licensed per year by tier and number of database connections, and additional deployment locations cost extra. Since it runs in your environment, plan infrastructure and operations. Have the data protection officer confirm that the synthetic or masked output meets your anonymization requirements.

The Tulu 3 SFT Mixture is an open collection of instruction and chat examples for supervised fine-tuning. It shows how the Allen Institute for AI turned base models into its Tulu 3 assistants.

Key functions

• Chat-format examples for supervised fine-tuning of language models
• Includes persona-based synthetic data for math, code and instruction following

Compared with SDV (Synthetic Data Vault)

• Strongest elsewhere: United States.

Check before buying: Some subsets, such as No Robots, are licensed for non-commercial use only; remove them before commercial training. WildChat contains real user conversations, so review data protection for your use. The mixture is mainly English, so German performance needs additional data.

Isaac Sim is NVIDIA's robotics simulation platform built on Omniverse. Robotics and automation teams use it to model robots and facilities, generate synthetic training data and train and test control software before it runs on real hardware.

Key functions

• Generates synthetic training data with photorealistic rendering
• Isaac Lab trains robot policies with reinforcement and imitation learning on GPUs
• RTX and physics-based sensors simulate cameras and lidar for perception models

Compared with SDV (Synthetic Data Vault)

• Strongest elsewhere: United States.

Check before buying: Isaac Sim needs NVIDIA RTX hardware and internet access during the build to download Kit SDK extensions. Read the additional NVIDIA license for Omniverse components before commercial use. Your team maintains the installation, as there is no SLA on the open source code itself.