kitio.aiWeights & Biases vs Union.ai
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Weights & Biases has the lower starting price: about $60 a month, against $950 for Union.ai.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Experiment tracking
- Hyperparameter sweeps
- Model registry
- Weave LLM tracing
- Reports
- Durable, resumable workflows
- Runs in your own cloud
- Distributed training
- Inference gateway
- Multi-cluster scheduling
- Lineage and artifacts
| Feature | Weights & Biases | Union.ai |
|---|---|---|
| Best for | Experiment tracking and LLM observability, now part of CoreWeave | Durable AI workflow runtime that runs inside your own cloud |
| Category | Models & APIs | Models & APIs |
| Pricing model | Freemium | Free trial |
| Starting price | $60/mo | $950/mo |
| Free plan | Yes | No, trial available |
| Made by | CoreWeave | Union.ai |
| Based in | United States | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
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Pricing compared
Weights & Biases has the lower starting price: about $60 a month, against $950 for Union.ai.
Free plan
Cheapest paid plan
Top plan
Free trial
3 plans
Free
Free
- Experiment tracking for individuals
- Limited storage
Pro
$60/mo
- Starting price
- Team collaboration features
- Higher usage limits
Enterprise
Contact sales
- SSO and advanced security
- Dedicated support
2 plans
Team
$950/mo
- Minimum, credited back as usage
- 2 active clusters
- 30-day data retention
- Standard 12x5 support
Enterprise
Custom
- Annual commit credited to usage
- Volume discounts on every meter
- Multi-region and multi-cloud
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Weights & Biases
- Industry-standard experiment tracking
- Polished dashboards
- Covers training and LLM apps
- Pricing jumps for larger teams
- Weave ingestion billed by size
- Sign-in moved to CoreWeave
Union.ai
- Data never leaves your infrastructure
- Failed steps resume where they stopped
- Plain Python on top of open-source Flyte
- $950 monthly minimum after the first month
- Meant for platform teams, not beginners
- Usage pricing takes effort to estimate
Which one should you choose?
Choose Weights & Biases if you want:
- Industry-standard experiment tracking
- Polished dashboards
- Covers training and LLM apps
Watch out: pricing jumps for larger teams.
Choose Union.ai if you want:
- Data never leaves your infrastructure
- Failed steps resume where they stopped
- Plain Python on top of open-source Flyte
Watch out: $950 monthly minimum after the first month.
Weights & Biases vs Union.ai FAQ
What is the difference between Weights & Biases and Union.ai?
Weights & Biases: Experiment tracking and LLM observability, now part of CoreWeave. Union.ai: Durable AI workflow runtime that runs inside your own cloud. Both are models & apis tools.
Is Weights & Biases or Union.ai cheaper?
Weights & Biases has the lower starting price: about $60 a month, against $950 for Union.ai.
Do Weights & Biases and Union.ai have free plans?
Weights & Biases: Yes. Union.ai: No, trial available.
Who makes Weights & Biases?
Weights & Biases is made by CoreWeave, based in United States.
Who makes Union.ai?
Union.ai is made by Union.ai, based in United States.
Which should I choose, Weights & Biases or Union.ai?
Choose Weights & Biases if you value industry-standard experiment tracking and polished dashboards. Choose Union.ai if you value data never leaves your infrastructure and failed steps resume where they stopped.