Cybersecurity · head to head
OWASP ZAP vs Seldon
OWASP ZAP
Cybersecurity
Free, open-source web application scanner and intercepting proxy, now governed by the Software Security Project.
- From
- Free
- Rated
- -
Seldon
Machine Learning
Kubernetes model serving whose current version is licensed under the Business Source Licence
- From
- Free
- Rated
- -
The short version
- Each has a real cost: OWASP ZAP authenticated scanning of modern single-page applications is the hard part and ZAP makes you build it by hand: session handling, token refresh and login scripts are configured per application, and a misconfigured session means the scanner logs itself out and reports a clean result for pages it never reached.; 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: OWASP ZAP covers Intercepting proxy, Seldon covers Kubernetes custom resources.
- Prices and features above were last checked on 30 August 2026.
Where they differ
Only the attributes on which OWASP ZAP and Seldon actually diverge.
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 OWASP ZAP
- Intercepting proxy
- Passive scanner
- Active scanner
- AJAX spider
- Automation Framework
- Headless daemon and REST API
- Docker images
- Add-on marketplace
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.
OWASP ZAP
- Adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handfulnot Seldon
- Manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per testernot Seldon
- Teaching developers what an attack against their own endpoint looks like, using a tool they can install themselvesnot Seldon
- Pre-release regression scanning of an internal application that would never justify a commercial DAST subscriptionnot Seldon
Seldon
- Serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate servicesnot OWASP ZAP
- Running genuine production experiments where a share of live traffic goes to a candidate model and the results are comparednot OWASP ZAP
- Regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on laternot OWASP ZAP
- Organisations with an established Kubernetes platform team who want serving expressed as manifests under existing deployment controlsnot OWASP ZAP
Where each one falls short
Documented limitations, not opinions. Every one is a constraint you would hit in normal use.
OWASP ZAP
- Authenticated scanning of modern single-page applications is the hard part and ZAP makes you build it by hand: session handling, token refresh and login scripts are configured per application, and a misconfigured session means the scanner logs itself out and reports a clean result for pages it never reached.
- There is no support contract in the product, so when a scan breaks the day before a release the escalation path is a GitHub issue and a community chat, which is not an answer that satisfies a delivery manager or an auditor who wants a named responsible party.
- Active scanning sends genuine attack traffic, so it can create records, trigger emails, exhaust rate limits or destabilise a fragile environment, and pointing it at production without prior agreement produces an incident rather than a test result.
- Output needs triage: passive rules generate large volumes of low-severity informational findings about headers and cookie flags that bury the few results that matter, and a team without someone tuning the rule set stops reading the report within a few sprints.
- As a dynamic scanner it can only test what it can reach, so authorisation flaws between accounts, business logic abuse and anything behind an undiscovered endpoint go unreported, and a passing ZAP scan is evidence of nothing more than the absence of the classes of bug it looks for.
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
OWASP ZAP
Free- Free & Open SourceFree
- Full functionality
- Active & passive scanning
- Spider
Seldon
Free- Seldon CoreFree
- Open source
- Kubernetes deployment
- Model serving
- Seldon DeployFree
- Enterprise features
- GUI
- Monitoring
Which should you pick?
Choose OWASP ZAP if
- You need intercepting proxy.
- You want to start without paying.
- You work on Desktop, Cli, Api.
- You also want passive scanner.
Choose Seldon if
- You need kubernetes custom resources.
- You want to start without paying.
- You work on Linux.
- You also want inference graphs.
Questions people ask
- Is OWASP ZAP or Seldon better?
- Neither clearly leads. OWASP ZAP 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, OWASP ZAP or Seldon?
- OWASP ZAP starts at Free and Seldon at Free.
- Does OWASP ZAP or Seldon run on more platforms?
- OWASP ZAP runs on Desktop, Cli, Api. Seldon runs on Linux.
- Can I use OWASP ZAP for free?
- Both have a free tier, so you can try either at no cost before committing.
- What is OWASP ZAP best used for?
- OWASP ZAP is most often used for adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handful, manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per tester, teaching developers what an attack against their own endpoint looks like, using a tool they can install themselves, pre-release regression scanning of an internal application that would never justify a commercial dast subscription. Of those, adding a baseline security scan to every application's pipeline where per-target commercial licensing would limit coverage to a handful and manual penetration testing that needs an intercepting proxy, request replay and fuzzing without a paid licence per tester are not what Seldon is typically brought in for.
- What can OWASP ZAP do that Seldon cannot?
- OWASP ZAP covers Intercepting proxy, Passive scanner, Active scanner, AJAX spider. Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol.
Answered from the vendors’ own pages
OWASP ZAP: Is it still called OWASP ZAP?
The project left OWASP in August 2024 and is now governed by the Software Security Project, with core development sponsored by Checkmarx. The tool is now just ZAP, though most existing documentation, courses and search results still use the OWASP name.
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.
OWASP ZAP: Is it free for commercial use?
Yes. It is Apache 2.0 licensed, with no per-application, per-scan or per-user cost, and it can be used and modified commercially without a licence agreement.
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.
OWASP ZAP: Can it replace a penetration test?
No. It automates checks for known vulnerability classes against endpoints it can reach. It does not reason about business logic, chain findings into an attack, or test authorisation between accounts, which is most of what a tester actually does.
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.
OWASP ZAP: Does it run in CI?
Yes, through the official Docker images and the Automation Framework, which defines scan jobs in YAML so configuration lives in the repository. A baseline passive scan is the usual starting point because it is fast and non-intrusive.
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.
OWASP ZAP: How does it compare to Burp Suite?
Burp Suite Professional is the more polished manual testing tool and has a stronger scanner and extension ecosystem, but it is licensed per tester and Burp Suite Enterprise per target. ZAP is the better fit where cost per target is the binding constraint; many teams use both.
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.
Related pages
Other head to heads
- OWASP ZAP vs 1Password
- OWASP ZAP vs Bitdefender Total Security
- OWASP ZAP vs Norton 360
- OWASP ZAP vs LastPass
- OWASP ZAP vs Bitwarden
- OWASP ZAP vs Burp Suite
- OWASP ZAP vs Metasploit
- OWASP ZAP vs Wireshark
- OWASP ZAP vs authentik
- OWASP ZAP vs Authelia
- OWASP ZAP vs Infisical
- OWASP ZAP vs Trivy
- OWASP ZAP vs Feedzai
- OWASP ZAP vs Frontegg
- OWASP ZAP vs HashiCorp Boundary
- OWASP ZAP vs JumpCloud
- OWASP ZAP vs McAfee Total Protection
- OWASP ZAP vs AWS SageMaker
- OWASP ZAP vs DataRobot
- OWASP ZAP vs Azure Machine Learning
- OWASP ZAP vs Google Vertex AI
- OWASP ZAP vs BentoML
- OWASP ZAP vs Kubeflow
- OWASP ZAP vs Pachyderm
- OWASP ZAP vs MLflow
- OWASP ZAP vs DVC
- OWASP ZAP vs Weights & Biases
- OWASP ZAP vs Comet ML
- OWASP ZAP vs Dataiku
- OWASP ZAP vs Anaconda
- OWASP ZAP vs Domino Data Lab
- OWASP ZAP vs H2O.ai
- OWASP ZAP vs Hugging Face
- Seldon vs 1Password
- Seldon vs Bitdefender Total Security
- Seldon vs Norton 360
- Seldon vs LastPass
- Seldon vs Bitwarden
- Seldon vs Burp Suite
- Seldon vs Metasploit
- Seldon vs Wireshark
- Seldon vs authentik
- Seldon vs Authelia
- Seldon vs Infisical
- Seldon vs Trivy
- Seldon vs Feedzai
- Seldon vs Frontegg
- Seldon vs HashiCorp Boundary
- Seldon vs JumpCloud
- Seldon vs McAfee Total Protection
- Seldon vs AWS SageMaker
- Seldon vs DataRobot
- Seldon vs Azure Machine Learning
- Seldon vs Google Vertex AI
- Seldon vs BentoML
- Seldon vs Kubeflow
- Seldon vs Pachyderm
- Seldon vs MLflow
- Seldon vs DVC
- Seldon vs Weights & Biases
- Seldon vs Comet ML
- Seldon vs Dataiku
- Seldon vs Anaconda
- Seldon vs Domino Data Lab
- Seldon vs H2O.ai
- Seldon vs Hugging Face