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AI · head to head

Arize AI vs Fastly

Arize AI logo

Arize AI

AI

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

From
Free
Free plan
Yes
Full reviewWebsite
Fastly logo

Fastly

Cloud

High performance edge computing platform

From
Free
Free plan
Yes
Full reviewWebsite

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.; Fastly bandwidth is priced per region, and delivery to India, Africa and South Korea is $0.28 per GB against $0.12 in North America and Europe
  • They diverge on capability: Arize AI covers End-to-end tracing, Fastly covers Edge Compute.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

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

Attributes where Arize AI and Fastly differ
AttributeArize AIFastly
Pricing modelfreemiumusage-based
CategoryAICloud
FoundedUnknown2011

Identical on both: starting price (Free), free tier (Yes), platforms (web, api), 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 Fastly

  • Edge Compute
  • CDN
  • DDoS Protection
  • Real-time Analytics
  • Image Optimization
  • Video Streaming
  • API
  • Instant Purge

What people use each for

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

Arize AI

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

Fastly

  • Serving static and dynamic content through a global CDNnot Arize AI
  • Running edge logic and caching in front of an origin applicationnot 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.

Fastly

  • Bandwidth is priced per region, and delivery to India, Africa and South Korea is $0.28 per GB against $0.12 in North America and Europe
  • The same traffic therefore costs more than twice as much depending on where the audience is, which is invisible until the bill arrives
  • The free allowance is 100 GB of bandwidth and 1M requests a month
  • Requests are billed separately from bandwidth, at $0.01 per 10,000 above the first million
  • High volume rates past 50 TB are not published and require contacting sales

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

Fastly

Free
  • Free TrialFree
    • CDN
    • DDoS protection
    • Real-time analytics
  • Pay-As-You-GoFree
    • Usage-based pricing
    • Advanced features
    • Priority support

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.
Arize AI review

Choose Fastly if

  • You need edge compute.
  • You want to start without paying.
  • You work on Web, Api.
  • You also want cdn.
Fastly review

Questions people ask

Is Arize AI or Fastly better?
Neither clearly leads. Arize AI starts at Free and Fastly at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Arize AI or Fastly?
Arize AI starts at Free and Fastly at Free.
Does Arize AI or Fastly run on more platforms?
Arize AI runs on web, api. Fastly runs on Web, Api.
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 Fastly is typically brought in for.
What can Arize AI do that Fastly cannot?
Arize AI covers End-to-end tracing, Evaluation framework, Prompt testing and improvement, Alyx AI engineering agent. Fastly covers Edge Compute, CDN, DDoS Protection, Real-time Analytics.

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
Fastly: Does Fastly charge based on usage or a flat monthly fee?

Fastly operates on a usage-based model with volume discounts. They offer a free tier with 100 GB bandwidth and 1M requests for experimentation, then customers pay per unit consumed with tiered discounts as consumption increases.

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
Fastly: What are Fastly's main service packages and their costs?

Fastly offers Network Services Packages ($1,500-$6,000/month baseline), Security Packages (custom pricing), Compute Packages ($500/month entry level), and Observability Packages ($1,500/month entry level). Enterprise solutions include custom quotes for high-volume 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
Fastly: Can I start using Fastly for free?

Yes, Fastly offers a free tier with generous allowances for experimentation including 100 GB bandwidth and 1M requests. You can start building free and only pay when you use additional resources.

Source
Fastly: Are there surprise overage charges with Fastly?

Fastly advertises predictable pricing with no surprise overages. The pricing structure is designed to be transparent as consumption grows.

Source
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