AI · head to head
Vellum vs PromptLayer

Vellum
AI
Personalized AI assistant with persistent memory and autonomous action-taking
- From
- Free
- Rated
- -

PromptLayer
AI
Collaboration platform for prompt management, evaluation, and observability
- From
- Free
- Rated
- -
The short version
- Each has a real cost: Vellum pricing varies significantly by computational tier, making budget planning difficult; PromptLayer the free plan is capped at only 2,500 requests per month, quite limited for active production use.
- They diverge on capability: Vellum covers Persistent AI identity, PromptLayer covers Visual prompt management.
Where they differ
Only the attributes on which Vellum and PromptLayer actually diverge.
| Attribute | Vellum | PromptLayer |
|---|---|---|
| Pricing model | Freemium with paid plans and pay-as-you-go credits | freemium |
| Platforms | Web, macOS, iOS, Slack, Telegram, Terminal | web, api |
Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (AI).
What each one covers
Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.
Only in Vellum
- Persistent AI identity
- Long-term memory
- Email automation
- Calendar management
- Autonomous task execution
- Multi-device synchronization
- Custom plugins
- Open-source deployment
Only in PromptLayer
- Visual prompt management
- Agent observability
- Evaluations
- Version control
- Cost and latency monitoring
- Agent workflow tracing
What people use each for
The jobs each tool is most often brought in to do.
Vellum
- Personal productivity automation across email and calendarnot PromptLayer
- CRM updates and pipeline managementnot PromptLayer
- Expense report generation and managementnot PromptLayer
- Document drafting and content creationnot PromptLayer
- Meeting scheduling and calendar coordinationnot PromptLayer
PromptLayer
- Versioning and deploying prompts without code redeploysnot Vellum
- Running evaluations with human review before production releasenot Vellum
- Tracing multi-step agent workflows for debuggingnot Vellum
- Monitoring LLM cost and latency by featurenot Vellum
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
Vellum
- Pricing varies significantly by computational tier, making budget planning difficult
- Requires explicit permission for sensitive actions, limiting autonomy
- Self-hosting option may intimidate non-technical users
- Learning curve to develop customizations with plugins
PromptLayer
- The free plan is capped at only 2,500 requests per month, quite limited for active production use.
- The Team plan jumps to $500/month, a large step up from the $49/month Pro plan.
- Overage transaction fees apply on top of subscription costs, which can make total spend less predictable.
- Enterprise-grade features like HIPAA BAAs and custom deployment require contacting sales.
Pricing, plan by plan
Vellum
Free- FreeFree
- Starter credits included
- Basic features
- Mighty$30/month
- 1 vCPU, 2 GiB RAM
- 10 GB storage
- Included usage allowance
- Super$100/month
- 2.5 vCPU, 5 GiB RAM
- 30 GB storage
- Assistant email and subdomain
- Ultra$200/month
- 4 vCPU, 8 GiB RAM
- 60 GB storage
- Assistant email and subdomain
PromptLayer
Free- FreeFree
- 5 users
- 2,500 requests/month
- 1 workspace
- Pro$49/month
- Unlimited playgrounds and workspaces
- 150MB datasets
- Pay-as-you-go overage at $0.003/transaction
- Team$500/month
- 25 users
- 100k+ monthly requests
- Webhooks
- Enterprise$undefined/mo
- Custom limits
- Role-based access controls
- HIPAA with BAA
Which should you pick?
Choose Vellum if
- You need persistent ai identity.
- You want to start without paying.
- You work on Web, macOS, iOS, Slack, Telegram, Terminal.
- You also want long-term memory.
Choose PromptLayer if
- You need visual prompt management.
- You want to start without paying.
- You work on web, api.
- You also want agent observability.
Questions people ask
- Is Vellum or PromptLayer better?
- Neither clearly leads. Vellum starts at Free and PromptLayer at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
- Which is cheaper, Vellum or PromptLayer?
- Vellum starts at Free and PromptLayer at Free.
- Does Vellum or PromptLayer run on more platforms?
- Vellum runs on Web, macOS, iOS, Slack, Telegram, Terminal. PromptLayer runs on web, api.
- Can I use Vellum for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is Vellum best used for?
- Vellum is most often used for personal productivity automation across email and calendar, crm updates and pipeline management, expense report generation and management, document drafting and content creation. Of those, personal productivity automation across email and calendar and crm updates and pipeline management are not what PromptLayer is typically brought in for.
- What can Vellum do that PromptLayer cannot?
- Vellum covers Persistent AI identity, Long-term memory, Email automation, Calendar management. PromptLayer covers Visual prompt management, Agent observability, Evaluations, Version control.
Answered from the vendors’ own pages
Vellum: How does Vellum protect my data privacy?
Vellum uses permission-based controls requiring explicit approval for sensitive actions. Data is encrypted and the option for self-hosting provides complete data control. Open-source deployment option allows hosting on your own infrastructure.
SourcePromptLayer: What does PromptLayer cost?
PromptLayer has a free plan, a Pro plan at $49/month, a Team plan at $500/month, and custom Enterprise pricing, with additional usage billed per transaction beyond plan limits.
SourceVellum: Can I use Vellum for business team collaboration?
Vellum is primarily designed as a personal assistant with persistent identity. For team collaboration, platforms like Lindy offer better multi-user features with shared credit pools and Slack workspace integration.
SourcePromptLayer: Is there a free plan, and what are its limits?
The Free plan includes 5 users, 2,500 requests per month, 1 workspace, 250 monthly eval cell executions, and datasets up to 10MB.
SourceVellum: What does the free tier include?
Vellum offers free starter credits to begin using the platform. Beyond that, it operates on a pay-as-you-go credit model with paid tiers starting at $30/month for increased computational resources and bundled credits.
SourcePromptLayer: How is usage metered beyond the plan limits?
Additional usage is charged per transaction for requests, agent runs, and evaluation cell runs, at $0.003/transaction on Pro and $0.002/transaction on Team.
SourceRelated pages
More on PromptLayer
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