kitio.aiArize AI vs PromptLayer
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. PromptLayer has the lower starting price: about $49 a month, against $50 for Arize AI.
At a glance
Best for
Category
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Arize Phoenix open source
- Agent tracing
- Online evaluations
- Drift monitoring
- Debugging copilot
- Prompt registry
- Visual prompt editor
- Evaluation pipelines
- Request logging
- Release labels
| Feature | Arize AI | PromptLayer |
|---|---|---|
| Best for | AI observability and evaluation, plus the open-source Phoenix | Prompt management and evals for teams where non-engineers edit prompts |
| Category | Models & APIs | Models & APIs |
| Pricing model | Freemium | Freemium |
| Starting price | $50/mo | $49/mo |
| Free plan | Yes | Yes |
| Made by | Arize AI | PromptLayer |
| Based in | United States | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
|
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Pricing compared
PromptLayer has the lower starting price: about $49 a month, against $50 for Arize AI.
Free plan
Cheapest paid plan
Top plan
Free trial
3 plans
AX Free
Free
- 25k spans/month
- 1 GB ingestion/month
- 15 days retention
- Unlimited users
AX Pro
$50/mo
- 50k spans/month
- 10 GB ingestion/month
- 30 days retention
AX Enterprise
Contact sales
- Custom plans
4 plans
Free
Free
- 5 users
- 2.5K requests/month
- 1 workspace
Pro
$49/mo
- Unlimited workspaces and playgrounds
- 150MB max per dataset
- Overage $0.003 per request
Team
$500/mo
- 25 users
- 100K+ requests/month
- Overage $0.002 per request
Enterprise
Custom
- Custom limits
- RBAC and deployment approvals
- HIPAA with BAA
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
Arize AI
- Free open-source Phoenix
- Covers classic ML and LLMs
- Strong enterprise features
- AX costs rise with volume
- Two products can confuse
- Steeper setup than simple tools
PromptLayer
- Friendly for non-engineers
- Simple prompt versioning
- Backtests on real traffic
- Less depth on agent tracing
- Limits on lower plans
- Smaller ecosystem
Which one should you choose?
Choose Arize AI if you want:
- Free open-source Phoenix
- Covers classic ML and LLMs
- Strong enterprise features
Watch out: ax costs rise with volume.
Choose PromptLayer if you want:
- Friendly for non-engineers
- Simple prompt versioning
- Backtests on real traffic
Watch out: less depth on agent tracing.
Arize AI vs PromptLayer FAQ
What is the difference between Arize AI and PromptLayer?
Arize AI: AI observability and evaluation, plus the open-source Phoenix. PromptLayer: Prompt management and evals for teams where non-engineers edit prompts. Both are models & apis tools.
Is Arize AI or PromptLayer cheaper?
PromptLayer has the lower starting price: about $49 a month, against $50 for Arize AI.
Do Arize AI and PromptLayer have free plans?
Arize AI: Yes. PromptLayer: Yes.
Who makes Arize AI?
Arize AI is made by Arize AI, based in United States.
Who makes PromptLayer?
PromptLayer is made by PromptLayer, based in United States.
Which should I choose, Arize AI or PromptLayer?
Choose Arize AI if you value free open-source phoenix and covers classic ml and llms. Choose PromptLayer if you value friendly for non-engineers and simple prompt versioning.