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AI · head to head

AI21 Labs vs Arize AI

AI21 Labs logo

AI21 Labs

AI

Enterprise language AI solutions

From
Free
Rated
-
Full reviewWebsite
Arize AI logo

Arize AI

AI

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

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: AI21 Labs the free allowance is $10 of credit lasting 7 days rather than an ongoing free tier; Arize AI the free plan caps trace spans at 25,000 per month with only 15 days of retention.
  • They diverge on capability: AI21 Labs covers Jamba models, Arize AI covers End-to-end tracing.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which AI21 Labs and Arize AI actually diverge.

Attributes where AI21 Labs and Arize AI differ
AttributeAI21 LabsArize AI
Pricing modelusage-basedfreemium
PlatformsApi, Cloudweb, api
Founded2017Unknown

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 AI21 Labs

  • Jamba models
  • Long context
  • RAG engine
  • Writing tools
  • REST API
  • Amazon Bedrock
  • Cloud platforms
  • Api support

Only in Arize AI

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

What people use each for

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

AI21 Labs

  • Running long-context tasks on the Jamba model familynot Arize AI
  • Building and optimising production AI agents with Maestronot Arize AI
  • Routing between models to control cost and accuracynot Arize AI
  • Long-horizon agentic tasks needing stateful workspacesnot Arize AI

Arize AI

  • Tracing and debugging production AI agentsnot AI21 Labs
  • Running large-scale evaluations across traces and sessionsnot AI21 Labs
  • Improving prompts before production rolloutnot AI21 Labs
  • Storing and querying GenAI traces alongside a data warehousenot AI21 Labs

Where each one falls short

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

AI21 Labs

  • The free allowance is $10 of credit lasting 7 days rather than an ongoing free tier
  • Jamba Large is $2 per million input tokens and $8 per million output, so output-heavy work costs four times as much as input
  • Volume discounts, private cloud hosting and higher rate limits require a custom plan
  • Standard rate limits are not published

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.

Pricing, plan by plan

AI21 Labs

Free
  • Free TrialFree
    • 10 USD credits
    • 7-day trial period
    • No credit card required
  • Pay As You Go$undefined/mo
    • Usage-based pricing model
    • Access to all Foundation model APIs and SDK
    • Unlimited seats
  • Custom Plan$undefined/mo
    • Volume discounts on token pricing
    • Premium API rate limits
    • Private cloud hosting option

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

Which should you pick?

Choose AI21 Labs if

  • You need jamba models.
  • You want to start without paying.
  • You work on Api, Cloud.
  • You also want long context.
AI21 Labs review

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

Questions people ask

Is AI21 Labs or Arize AI better?
Neither clearly leads. AI21 Labs starts at Free and Arize AI at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, AI21 Labs or Arize AI?
AI21 Labs starts at Free and Arize AI at Free.
Does AI21 Labs or Arize AI run on more platforms?
AI21 Labs runs on Api, Cloud. Arize AI runs on web, api.
Can I use AI21 Labs for free?
Both have a free tier, so you can try either at no cost before committing.
What is AI21 Labs best used for?
AI21 Labs is most often used for running long-context tasks on the jamba model family, building and optimising production ai agents with maestro, routing between models to control cost and accuracy, long-horizon agentic tasks needing stateful workspaces. Of those, running long-context tasks on the jamba model family and building and optimising production ai agents with maestro are not what Arize AI is typically brought in for.
What can AI21 Labs do that Arize AI cannot?
AI21 Labs covers Jamba models, Long context, RAG engine, Writing tools. Arize AI covers End-to-end tracing, Evaluation framework, Prompt testing and improvement, Alyx AI engineering agent.

Answered from the vendors’ own pages

AI21 Labs: How much do AI21's Jamba Mini and Jamba Large models cost?

Jamba Mini costs $0.2 per 1M input tokens and $0.4 per 1M output tokens. Jamba Large is priced at $2 per 1M input tokens and $8 per 1M output tokens. Both models use usage-based billing with no monthly minimums.

Source
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
AI21 Labs: Does AI21 offer a free trial?

Yes, AI21 provides a free trial with 10 USD in credits for 7 days, no credit card required. The trial grants access to all Foundation models via API and SDK.

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
AI21 Labs: How do AI21's custom plans and volume discounts work?

Custom plans with volume discounts are available for enterprises but require contacting sales. These plans can include premium API rate limits, private cloud hosting, priority support, dedicated account managers, and expert consultancy.

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
AI21 Labs: What does AI21 mean by 30% token efficiency savings?

AI21 claims their tokenization delivers approximately 30% more text per token compared to other providers, which can reduce effective costs by roughly 30%. This applies primarily to English-language text averaging 1 word or 6 characters per token.

Source
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