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Machine Learning · head to head

Seldon vs Writer

Seldon logo

Seldon

Machine Learning

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

From
Free
Free plan
Yes
Full reviewWebsite
Writer logo

Writer

AI

Full-stack generative AI platform for enterprise content and agents

From
On request
Free plan
No
Full reviewWebsite

The short version

  • Only Seldon has a free tier, so it costs nothing to try first.
  • Each has a real cost: 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.; Writer pricing is not publicly disclosed and requires a sales conversation, unlike consumer AI writing tools.
  • They diverge on capability: Seldon covers Kubernetes custom resources, Writer covers Palmyra LLMs.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Seldon and Writer actually diverge.

Attributes where Seldon and Writer differ
AttributeSeldonWriter
Starting priceFreeOn request
Pricing modelfreemiumquote
Free tierYesNo
PlatformsLinuxweb, api
CategoryMachine LearningAI
Founded20142020

Identical on both: 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 Seldon

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

Only in Writer

  • Palmyra LLMs
  • Knowledge Graph
  • No-code agent builder
  • Brand compliance
  • AI writing assistant
  • Enterprise security controls

What people use each for

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

Seldon

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

Writer

  • Enterprise marketing content generationnot Seldon
  • AI-powered knowledge assistants grounded in company datanot Seldon
  • Building custom generative AI agents without codenot Seldon
  • Brand and compliance-consistent copywriting at scalenot Seldon

Where each one falls short

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

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.

Writer

  • Pricing is not publicly disclosed and requires a sales conversation, unlike consumer AI writing tools.
  • Its proprietary Palmyra models are less widely benchmarked and documented than general-purpose models like GPT or Claude.
  • Primarily positioned for large enterprises, making it less accessible or cost-effective for individuals and small teams.

Pricing, plan by plan

Seldon

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

Writer

On request
  • Starter$undefined/month
    • For teams starting with agentic AI
    • Up to 5 users
    • 14-day free trial, no card required
  • Enterprise$undefined/month
    • Contact sales
    • Unlimited users, teams and free collaborators
    • Lite seats for invited users

Which should you pick?

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

Choose Writer if

  • You need palmyra llms.
  • You work on web, api.
  • You also want knowledge graph.
Writer review

Questions people ask

Is Seldon or Writer better?
Neither clearly leads. Seldon starts at Free and Writer at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Seldon or Writer?
Seldon has a free tier; the other does not. Paid plans start at Free for Seldon and On request for Writer.
Does Seldon or Writer run on more platforms?
Seldon runs on Linux. Writer runs on web, api.
Can I use Seldon for free?
Yes. Seldon has a free tier, so you can try it without paying. Writer starts at On request.
What is Seldon best used for?
Seldon is most often used for serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate services, running genuine production experiments where a share of live traffic goes to a candidate model and the results are compared, regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on later, organisations with an established kubernetes platform team who want serving expressed as manifests under existing deployment controls. Of those, serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate services and running genuine production experiments where a share of live traffic goes to a candidate model and the results are compared are not what Writer is typically brought in for.
What can Seldon do that Writer cannot?
Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol. Writer covers Palmyra LLMs, Knowledge Graph, No-code agent builder, Brand compliance.

Answered from the vendors’ own pages

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.

Writer: What does Writer cost?

Writer does not publish prices. There are two tiers: Starter, for teams up to five users, with a 14-day free trial and no card required, and Enterprise, which is contact-sales and adds unlimited users and teams.

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.

Writer: What is the difference between Pro and Lite seats?

Pro is the standard paid seat, with full access to create, customise and automate workflows. Lite seats exist only on Enterprise, letting invited users view and run existing playbooks with limited monthly Agent use before needing a Pro seat.

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.

Writer: What does Writer do with customer data?

Writer states a zero data retention approach and says customers retain full ownership of their data. By default it does not train or improve its models on customer data, rather than requiring an opt-out.

Source
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.

Writer: Which compliance standards does Writer meet?

Writer says it adheres to GDPR, HIPAA, SOC 2 Type II and PCI. HIPAA and SOC 2 Type II certifications and reports are available on request, and only for Enterprise plans.

Source
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.

Writer: Are there discounts for nonprofits or education?

Yes. Writer offers 20% off the Starter and Enterprise plans to nonprofits and educational institutions, claimed by emailing from a nonprofit or .edu address.

Source
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