MOSTLY AI alternatives: 5 tools compared (October 2026)
MOSTLY AI: Platform and open-source SDK from Vienna for synthetic tabular data with differential privacy and an AI assistant for data analysis. These 5 tools cover the same task (synthetic data). They are ranked by how many of MOSTLY AI's strongest markets they share, then by how complete their profile is.
Targets companies under 50 employees and offers a free plan.
Picked from our profile data, which we check against vendor pages. No vendor paid for a placement.
What MOSTLY AI does
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.
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
MOSTLY AI was founded in Vienna; since June 2026 the brand belongs to the Dutch vendor Syntho and operates as MOSTLY AI powered by Syntho.
Before you switch: 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.
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 MOSTLY AI
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.
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 MOSTLY AI
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.
SDV (Synthetic Data Vault) is a Python library for data scientists who need synthetic versions of single tables or whole relational databases for testing, sharing or model training.
Key functions
Generative synthesizers create synthetic single tables and relational databases
Constraint augmented generation and differential privacy as paid bundles
SDMetrics evaluates quality and privacy of synthetic data
Compared with MOSTLY AI
Publishes a price (from $500 per month); MOSTLY AI quotes on request.
Targets companies under 50 employees, which MOSTLY AI does not.
Check before buying: Check the Business Source License terms before commercial use of SDV Community, since commercial use is limited. Running SDV locally keeps data in your environment, but your team maintains the Python stack. Have privacy experts review whether synthetic output derived from personal data is anonymous for your purpose.
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 MOSTLY AI
Targets companies under 50 employees, which MOSTLY AI does not.
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 MOSTLY AI
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.
All 5 alternatives by buying criteria
MOSTLY AI alternatives by price, trial, hosting and security
Not stated means we found no statement on the vendor's site. Data as of each profile's last check.
The market around MOSTLY AI: 6 tools for this task
17 % Publish a price (1/6)
50 % Free plan (3/6)
0 % Free trial (0/6)
0 % EU hosting option (0/6)
33 % Headquartered in Europe (2/6)
0 % Single sign-on (0/6)
MOSTLY AI is among the tools that price on request. Most vendors in this category sell through demos and quotes, so ask two or three for an offer on the same scope before you compare.
Source: ai-toolfinder.com dataset, full profiles only.
Why teams look beyond MOSTLY AI
MOSTLY AI quotes prices on request. 1 of the alternatives below have a published pricing model.
MOSTLY AI lists no free plan or free trial in our data. 3 alternatives do.
MOSTLY AI does not target companies under 50 employees. 2 alternatives do.
It depends on your country and company size. In our data, Appen, Syntho and SDV (Synthetic Data Vault) share the most strong markets with MOSTLY AI, so they are the closest fit if you work where MOSTLY AI is strong. Filter the list by country and size to narrow it down.
Is there a free alternative to MOSTLY AI?
SDV (Synthetic Data Vault), Tulu 3 SFT Mixture and NVIDIA Isaac Sim offer a free plan or a free trial according to the vendors. Check the limits of free plans before you rely on them for employee data.
Which MOSTLY AI alternatives can host data in the EU?
None of the listed alternatives states an EU hosting option in our data.
Which MOSTLY AI alternatives publish their prices?
SDV (Synthetic Data Vault) show prices on their websites, for example SDV (Synthetic Data Vault) from $500 per month. The others quote after a demo.
Are there European alternatives to MOSTLY AI?
Syntho is headquartered in Europe. A European seat does not guarantee EU hosting, so check the data processing agreement and the list of subprocessors.
Appen
