Union.ai records 17,787 monthly visits with -28.4% month-over-month growth and Freemium, Contact for Pricing pricing. Vast.ai records 1,257,554 monthly visits with +2.8% growth and Paid pricing.
The durable AI runtime that runs in your cloud, not ours
Rent cloud GPUs by the second from a global marketplace
| Dimension / Metric | | |
|---|---|---|
| Official Domain | union.ai | vast.ai |
| Pricing Model | Freemium, Contact for Pricing | Paid |
| Monthly Visits | 17.79K (17,787) | 1.26M (1,257,554) |
| MoM Traffic Delta | -7.04K (-28.4%) | +34.24K (+2.8%) |
| Primary Market & Share | 🇺🇸 United States (52.8%) | 🇺🇸 United States (16.7%) |
| Direct Visits / mo | 7.04K | 937.11K |
| User Rating | 4.4 | 4.6 |
| Supported Platforms | Website | Website |
The durable AI runtime that runs in your cloud, not ours
Tasks, traces and artifacts survive infrastructure failure. Runs fork, recover and replay from the last good step instead of starting over, with retries and caching handled by the runtime.
Named, typed and versioned artifacts wire teams together, with lineage showing which run produced each version and which downstream tasks consume it.
Run the control plane in Union's cloud while workloads execute on clusters in your AWS, GCP, Azure or neocloud account, under your own security perimeter.
Bring OpenAI, Claude, PydanticAI or CrewAI agents; each turn is traced and sandboxed in ephemeral containers, MCP servers and human approvals supported.
Rent cloud GPUs by the second from a global marketplace
Rent from a global pool of 20,000+ GPUs spanning more than 60 GPU types, from RTX 3060-class cards to GB200s, across 40+ data centers.
Choose on-demand for guaranteed uptime, interruptible at 50%+ cheaper, or reserved terms at up to 50% off with guaranteed capacity.
Pay only for the compute you use with per-second billing and no minimum hours, so experiments and short jobs stay affordable.
Provision and optimize instances entirely through code using the CLI, Python SDK, or REST API, which also makes the platform agent-ready.
Offers a polished managed Kubernetes cloud experience with better template stability, but can be slightly more expensive.
Offers a polished managed Kubernetes cloud experience with better template stability, but can be slightly more expensive.
SpecialistTogether AI is the AI Native Cloud — a full-stack platform for running, fine-tuning and training open-source models. It spans serverless inference APIs, dedicated endpoints, GPU clusters, post-training and storage, all backed by in-house systems research.
SpecialistTogether AI is the AI Native Cloud — a full-stack platform for running, fine-tuning and training open-source models. It spans serverless inference APIs, dedicated endpoints, GPU clusters, post-training and storage, all backed by in-house systems research.
SpecialistServerless cloud infrastructure for AI and data workloads
SpecialistServerless cloud infrastructure for AI and data workloads
Provides enterprise-grade AI cloud infrastructure with managed ML tools, replacing peer-to-peer rentals with reliable data centers.
Provides enterprise-grade AI cloud infrastructure with managed ML tools, replacing peer-to-peer rentals with reliable data centers.
Free / Open-sourceLeverages distributed idle consumer hardware to deliver significantly cheaper inference and container workloads, with lower reliability guarantees.
Free / Open-sourceLeverages distributed idle consumer hardware to deliver significantly cheaper inference and container workloads, with lower reliability guarantees.
SpecialistLow-cost serverless inference APIs for 200+ open models
The AI cloud built by the creators of PyTorch Lightning
Builds large-scale data center GPU clusters tailored for heavy model training, lacking peer-to-peer spot pricing.
Builds large-scale data center GPU clusters tailored for heavy model training, lacking peer-to-peer spot pricing.
Provides instant persistent SSH instances with simple per-second billing, matching Vast.ai's developer-focused flexibility.
Provides instant persistent SSH instances with simple per-second billing, matching Vast.ai's developer-focused flexibility.
Persistent Ubuntu cloud VMs built for AI agent factories
Specializes in agent-first per-second GPU rentals, closely mirroring Vast.ai's developer and agent-centric workflow.
Specializes in agent-first per-second GPU rentals, closely mirroring Vast.ai's developer and agent-centric workflow.
Managed Ray platform for scaling AI workloads
