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AI · head to head

Helicone vs Seldon

Helicone logo

Helicone

AI

Open-source LLM observability and gateway platform for AI applications

From
Free
Rated
-
Full reviewWebsite
Seldon logo

Seldon

Machine Learning

Kubernetes model serving whose current version is licensed under the Business Source Licence

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Helicone the free Hobby plan is capped at 10,000 requests per month, which teams with production traffic can exceed quickly.; Seldon seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • They diverge on capability: Helicone covers Request dashboard and tracking, Seldon covers Kubernetes custom resources.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Helicone and Seldon actually diverge.

Attributes where Helicone and Seldon differ
AttributeHeliconeSeldon
Platformsweb, apiLinux
CategoryAIMachine Learning
FoundedUnknown2014

Identical on both: starting price (Free), pricing model (freemium), 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 Helicone

  • Request dashboard and tracking
  • Sessions and segments
  • Helicone Query Language (HQL)
  • Prompt datasets and improvement
  • Playground
  • Rate limits and alerts

Only in Seldon

  • Kubernetes custom resources
  • Inference graphs
  • Traffic strategies
  • Open Inference Protocol
  • Alibi Explain
  • Alibi Detect
  • Kafka-backed pipelines in v2
  • Commercial control plane

What people use each for

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

Helicone

  • Monitoring cost and latency of production LLM applicationsnot Seldon
  • Debugging multi-step agent sessionsnot Seldon
  • Managing and iterating on prompts across a teamnot Seldon
  • Routing requests across multiple LLM providersnot Seldon

Seldon

  • Serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate servicesnot Helicone
  • Running genuine production experiments where a share of live traffic goes to a candidate model and the results are comparednot Helicone
  • Regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on laternot Helicone
  • Organisations with an established Kubernetes platform team who want serving expressed as manifests under existing deployment controlsnot Helicone

Where each one falls short

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

Helicone

  • The free Hobby plan is capped at 10,000 requests per month, which teams with production traffic can exceed quickly.
  • Advanced compliance features like SOC 2 and HIPAA are only available starting at the $799/month Team plan.
  • Usage beyond the free tier is billed on top of the base subscription, adding cost unpredictability at scale.
  • On-premises deployment is restricted to the custom Enterprise tier.

Seldon

  • Seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship.
  • Core v1 remains Apache 2.0 but is in maintenance, so taking the free route means running software that receives no new development while the architecture it belongs to moves on without it.
  • Version 2 is a different system rather than a newer release, with different custom resources, a scheduler component and a Kafka-based pipeline model, so migrating from v1 is a re-implementation of every deployment manifest rather than an upgrade.
  • Kafka is a dependency for v2 pipelines, so an organisation that does not already operate it takes on a distributed log with its own storage, retention, rebalancing and failure modes purely in order to serve models.
  • Everything assumes Kubernetes fluency and the failure modes are Kubernetes failure modes, custom resource version mismatches, an operator that will not reconcile, admission webhooks and resource limits terminating an inference pod mid-request, so it needs a platform engineer rather than a data scientist.

Pricing, plan by plan

Helicone

Free
  • HobbyFree
    • 10,000 free requests
    • 1 GB storage
    • 1 seat
  • Pro$79/month
    • 10K free requests included, usage-based beyond
    • 7-day free trial
    • Unlimited playgrounds and workspaces
  • Team$799/month
    • 5 organizations
    • SOC 2 and HIPAA compliance
    • Dedicated Slack channel access
  • Enterprise$undefined/mo
    • Custom MSAs and SAML SSO
    • On-premises deployment
    • Bulk cloud discounts

Seldon

Free
  • Seldon CoreFree
    • Open source
    • Kubernetes deployment
    • Model serving
  • Seldon DeployFree
    • Enterprise features
    • GUI
    • Monitoring

Which should you pick?

Choose Helicone if

  • You need request dashboard and tracking.
  • You want to start without paying.
  • You work on web, api.
  • You also want sessions and segments.
Helicone review

Choose Seldon if

  • You need kubernetes custom resources.
  • You want to start without paying.
  • You work on Linux.
  • You also want inference graphs.
Seldon review

Questions people ask

Is Helicone or Seldon better?
Neither clearly leads. Helicone starts at Free and Seldon at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Helicone or Seldon?
Helicone starts at Free and Seldon at Free.
Does Helicone or Seldon run on more platforms?
Helicone runs on web, api. Seldon runs on Linux.
Can I use Helicone for free?
Both have a free tier, so you can try either at no cost before committing.
What is Helicone best used for?
Helicone is most often used for monitoring cost and latency of production llm applications, debugging multi-step agent sessions, managing and iterating on prompts across a team, routing requests across multiple llm providers. Of those, monitoring cost and latency of production llm applications and debugging multi-step agent sessions are not what Seldon is typically brought in for.
What can Helicone do that Seldon cannot?
Helicone covers Request dashboard and tracking, Sessions and segments, Helicone Query Language (HQL), Prompt datasets and improvement. Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol.

Answered from the vendors’ own pages

Helicone: What does Helicone cost?

Helicone offers a free Hobby plan, a Pro plan at $79/month, a Team plan at $799/month, and custom Enterprise pricing, with usage-based charges applying beyond included request limits.

Source
Seldon: Is Seldon open source?

Partly, and this is the thing to check before you build on it. Core v1 is Apache 2.0 but in maintenance. Core v2 was moved to the Business Source Licence in 2024, which allows evaluation but not unlicensed production use. Verify the current licence of each component you intend to run, including MLServer and the Alibi libraries.

Helicone: Is there a free plan, and what are its limits?

The free Hobby plan includes 10,000 requests per month, 1 GB of storage, 1 seat, and 1 organization, aimed at kickstarting AI projects.

Source
Seldon: What is the difference between v1 and v2?

Architecture, not just version number. v2 introduces a scheduler, a different set of custom resources and Kafka-backed pipelines. Manifests, mental model and operations all change, so treat a move as a project.

Helicone: Are there discounts available?

Helicone offers 50% off the first year for qualifying startups, discounts for non-profits, a $100 annual credit for open-source projects, and free access for students.

Source
Seldon: Do I need Kubernetes?

Yes. It is a Kubernetes-native system and there is no meaningful deployment without a cluster and someone competent to run it.

Seldon: What is MLServer?

Seldon's Python inference server implementing the Open Inference Protocol, usable inside Seldon deployments or on its own. Check its current licence alongside Core's, since the company has moved projects onto the Business Source Licence.

Seldon: Do I have to run Kafka?

For v2 pipelines, yes. If you only need single models served, that dependency is a large amount of infrastructure for the benefit, and a simpler serving layer may be the better answer.

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