Google Vertex AI vs Letta: Which is Better in 2026?
Choosing between Google Vertex AI and Letta comes down to understanding what each tool does best. This comparison breaks down the key differences so you can make an informed decision based on your specific needs, not marketing claims.
Bottom line: Google Vertex AI is our overall pick for AI & automation workflows. Pick Letta if you need AI agents.
Short on time? Here's the quick answer
We've tested both tools. Here's who should pick what:
Google Vertex AI
Unified AI platform for ML development
Best for you if:
- • You need AI & automation features specifically
- • Google Vertex AI is a unified ML platform for building, deploying, and managing AI models
- • It provides AutoML, custom training, model registry, and deployment to endpoints
Letta
Build AI agents that learn and improve from experience
Best for you if:
- • You want to try before committing
- • You need AI agents features specifically
- • Develops AI agents with continuous learning and self-improvement capabilities.
- • Focuses on solving AI's memory problem for more human-like agents.
| At a Glance |  Google Vertex AI |  Letta |
|---|---|---|
Starts at | Custom | FreeFree tier available |
Best For | AI & Automation | AI Agents |
Rating | 4.3/5 | - |
Free plan | No | Yes |
Choose Google Vertex AI or Letta?
Choose Google Vertex AI if
Unified AI platform for ML development
- Unified ML platform
- AutoML included
- Good model management
- Your work is AI & automation-shaped, not AI agents-shaped
Choose Letta if
Build AI agents that learn and improve from experience
- Addresses a critical limitation in current AI: memory and continuous learning.
- Provides developer tools for building advanced, adaptive AI agents.
- Backed by significant research and expertise from leading AI institutions.
- You want a free tier before you commit
- Your work is AI agents-shaped, not AI & automation-shaped
| Feature | Google Vertex AI | Letta |
|---|---|---|
| Pricing Model | Paid | Freemium |
| User Rating | ★4.3/5 651 reviews | No ratings yet |
| Categories | AI & AutomationCloud & Infrastructure | AI AgentsDeveloper Tools |
In-Depth Analysis
Google Vertex AI
Unified AI platform for ML development
Strengths
- +Unified ML platform
- +AutoML included
- +Good model management
- +Gemini integration
- +Feature store
Weaknesses
- -Expensive
- -Complex pricing
- -Learning curve
- -Vendor lock-in
- -Documentation gaps
Key features
Letta
Build AI agents that learn and improve from experience
Strengths
- +Addresses a critical limitation in current AI: memory and continuous learning.
- +Provides developer tools for building advanced, adaptive AI agents.
- +Backed by significant research and expertise from leading AI institutions.
- +Emphasizes open AI principles and developer empowerment.
Weaknesses
- -The technology is highly specialized, potentially requiring advanced AI development knowledge.
- -Specific pricing and availability details for products like the SDK are not readily apparent.
- -The focus on foundational research means some applications may still be emerging.
Key features
Pricing: Google Vertex AI vs Letta
| Plan | Google Vertex AI | Letta |
|---|---|---|
| Tier 1 | Free Free Tier | $0 /month Free |
| Tier 2 | Usage-based Pay-as-you-go | $20 /month Pro |
| Tier 3 | N/A | Contact us Teams / Enterprise |
Pricing verified from each vendor's public pricing page. Compare in detail on Google Vertex AI pricing and Letta pricing.
Who Should Use What?
On a budget?
Letta has a free tier. Google Vertex AI is paid only.
Go with: Letta
Want the highest-rated option?
Google Vertex AI is rated 4.3/5. Letta has no ratings yet.
Go with: Google Vertex AI
Value user reviews?
Google Vertex AI: 651 reviews (4.3/5). Letta: no ratings yet.
Go with: Google Vertex AI
3 Questions to Help You Decide
What's your budget?
Google Vertex AI is paid. Letta is freemium. Letta lets you start free.
What's your use case?
Google Vertex AI is a AI & automation tool. Letta is in AI agents. Pick the category that matches your needs.
How important are ratings?
Google Vertex AI is rated 4.3/5; Letta has no ratings yet.
Key Takeaways
Google Vertex AI
- Our pick for this comparison
Letta
- Has a free tier
- Better fit for AI agents
The Bottom Line
Google Vertex AI is our pick. Letta has a free tier if you want to test without paying.
Frequently Asked Questions
Is Google Vertex AI or Letta better?
Google Vertex AI is rated in our evaluation. Google Vertex AI is paid and Letta is freemium.
What are Google Vertex AI and Letta used for?
Google Vertex AI: Unified AI platform for ML development. Letta: Build AI agents that learn and improve from experience.
What does Google Vertex AI cost vs Letta?
Google Vertex AI is a paid tool. Letta is freemium (free tier + paid plans). Visit their websites for detailed pricing.