Softwr

AI · head to head

Arize AI vs Prefect

Arize AI logo

Arize AI

AI

AI engineering platform for observability and evaluation of agents and LLM apps

From
Free
Rated
-
Prefect logo

Prefect

Automation Integration

Python-first workflow orchestration that heals itself

From
Free
Rated
-

The short version

  • Each has a real cost: Arize AI the free plan caps trace spans at 25,000 per month with only 15 days of retention.; Prefect limited to Python-based workflows; other languages require API calls
  • They diverge on capability: Arize AI covers End-to-end tracing, Prefect covers Python function decorators.

Where they differ

Only the attributes on which Arize AI and Prefect actually diverge.

Attributes where Arize AI and Prefect differ
AttributeArize AIPrefect
Pricing modelfreemiumFreemium with per-user and usage-based tiers
Platformsweb, apiCloud, Self-hosted, VPC
CategoryAIAutomation Integration

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Arize AI

  • End-to-end tracing
  • Evaluation framework
  • Prompt testing and improvement
  • Alyx AI engineering agent
  • Custom dashboards
  • Data warehouse integrations

Only in Prefect

  • Python function decorators
  • Automatic resilience
  • Flexible deployment
  • Observable execution
  • Multiple scheduling
  • Webhooks
  • Open-source core

What people use each for

The jobs each tool is most often brought in to do.

Arize AI

  • Tracing and debugging production AI agentsnot Prefect
  • Running large-scale evaluations across traces and sessionsnot Prefect
  • Improving prompts before production rolloutnot Prefect
  • Storing and querying GenAI traces alongside a data warehousenot Prefect

Prefect

  • Orchestrating data pipeline workflows in Pythonnot Arize AI
  • Managing ML model training and inference jobsnot Arize AI
  • Building ETL and event-driven automationnot Arize AI
  • Monitoring and alerting on workflow healthnot Arize AI

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Arize AI

  • The free plan caps trace spans at 25,000 per month with only 15 days of retention.
  • Self-hosted deployment and Data Fabric integration are restricted to the custom-priced Enterprise tier.
  • Pricing beyond the $50/month Pro plan requires a custom quote, making cost planning less transparent at scale.
  • Advanced compliance features like HIPAA are only available on Enterprise.

Prefect

  • Limited to Python-based workflows; other languages require API calls
  • Hobby free tier severely limited for production use
  • Team plan billing per user scales quickly with team size
  • Less visual workflow builder compared to some competitors
  • Smaller ecosystem of pre-built connectors than alternatives

Pricing, plan by plan

Arize AI

Free
  • AX FreeFree
    • 25k trace spans/month
    • 1 GB storage/month
    • 15-day retention
  • AX Pro$50/month
    • 50k trace spans/month
    • 10 GB storage/month
    • 30-day retention
  • AX Enterprise$undefined/mo
    • Custom trace spans, storage, and retention
    • SaaS or self-hosted deployment
    • Managed agents and Data Fabric

Prefect

Free
  • HobbyFree
    • 2 users and 5 deployments
    • 500 minutes serverless monthly
    • 7-day run retention
  • Starter$100/month
    • 3 users and 20 deployments
    • 75 hours serverless compute
    • Bring-your-own infrastructure
  • Team$100/user/month
    • 4-8 users per plan tier
    • 100 deployments
    • 225 hours serverless monthly
  • Enterprise$null/custom
    • SSO and SAML authentication
    • Role-based access control
    • Multiple workspaces

Which should you pick?

Choose Arize AI if

  • You need end-to-end tracing.
  • You want to start without paying.
  • You work on web, api.
  • You also want evaluation framework.

Choose Prefect if

  • You need python function decorators.
  • You want to start without paying.
  • You work on Cloud, Self-hosted, VPC.
  • You also want automatic resilience.

Questions people ask

Is Arize AI or Prefect better?
Neither clearly leads. Arize AI starts at Free and Prefect at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Arize AI or Prefect?
Arize AI starts at Free and Prefect at Free.
Does Arize AI or Prefect run on more platforms?
Arize AI runs on web, api. Prefect runs on Cloud, Self-hosted, VPC.
Can I use Arize AI for free?
Both have a free tier, so you can try either at no cost before committing.
What is Arize AI best used for?
Arize AI is most often used for tracing and debugging production ai agents, running large-scale evaluations across traces and sessions, improving prompts before production rollout, storing and querying genai traces alongside a data warehouse. Of those, tracing and debugging production ai agents and running large-scale evaluations across traces and sessions are not what Prefect is typically brought in for.
What can Arize AI do that Prefect cannot?
Arize AI covers End-to-end tracing, Evaluation framework, Prompt testing and improvement, Alyx AI engineering agent. Prefect covers Python function decorators, Automatic resilience, Flexible deployment, Observable execution.

Answered from the vendors’ own pages

Arize AI: What does Arize AX cost?

Arize AX offers a free plan, a Pro plan at $50/month, and a custom-priced Enterprise plan, with pricing based on trace spans, storage, and retention needs.

Source
Prefect: What is included in the Hobby free plan?

Hobby includes 2 users, 5 deployments, 500 minutes of serverless compute monthly, and 7-day run retention.

Source
Arize AI: Is there a free plan, and what are its limits?

The AX Free plan includes 25,000 trace spans and 1 GB of storage per month with 15-day retention, plus unlimited users, evaluations, and experiments.

Source
Prefect: What is the difference between Starter and Team plans?

Starter is $100/month for 3 users and 20 deployments. Team is $100 per user per month for 4-8 users and 100 deployments.

Source
Arize AI: What deployment options are available?

Free and Pro plans are SaaS-only, while Enterprise customers can choose SaaS or self-hosted deployment with custom SLAs.

Source
Prefect: Can I deploy Prefect in my own infrastructure?

Yes, Starter and higher plans support bring-your-own-compute infrastructure and VPC deployments.

Source
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