DeepSeek
Open-weight reasoning models with a free web assistant.
Overview
DeepSeek pairs a free chat assistant with openly published models, making it a favourite for maths, code and self-hosted deployments.
Teams reach for DeepSeek when open-weight reasoning models with a free web assistant. It sits in the free bracket (Free web app · low-cost API) and is reviewed by AIAtlas editors against the tasks people actually bring to it, not marketing claims.
Best for
Where this tool consistently outperforms alternatives.
- Developers
- Students
- Researchers
Pricing
Indicative plans — always confirm on the official site.
Free
$0
Everyday use with fair limits.
- Core features
- Community support
- Usage caps
Paid
Popularlow-cost API
For individuals and small teams shipping daily.
- Highest-quality models
- Priority speed
- Full history and exports
Enterprise
Custom
Security, control and volume pricing.
- SSO and audit logs
- Data residency options
- Dedicated support
Pros & cons
Pros
- Excellent maths and code reasoning
- Free to use in the browser
- Open models for private deployment
Cons
- Fewer productivity integrations
- Data residency questions for some teams
Key features
What you actually get day to day.
Reasoning mode with visible thinking
Open weights you can self-host
Very cheap API pricing
Free unlimited web chat
Alternatives
Four similar tools worth comparing before you commit.
Frequently asked questions
Ready to try this AI?
Start with DeepSeek on the official site — Free web app · low-cost API.