Clair and Falco are complementary, both free and open source, but they secure different stages of the container lifecycle — Clair statically analyzes…
Best for Clair: Clair fits teams wanting free, self-hosted static vulnerability scanning integrated into a registry or CI/CD pipeline before images are deployed, as used by the Quay container registry, supporting Ubuntu, Debian, RHEL, SUSE, Oracle, Alpine, Amazon Linux, VMware Photon, and Python packages.
Best for Falco: Falco fits platform and security teams wanting free, CNCF-graduated runtime threat detection across hosts, containers, and Kubernetes with low-overhead eBPF monitoring and 50+ integrations to forward alerts to SIEM tooling.
At a Glance
Clair
Falco
Primary category
Security
Security
Rating
Not documented
Not documented
Pricing model
Open Source (Free)
Open Source
Starting price
Free
Free
Free plan
Yes
Yes
Free trial
Not documented
Not documented
Platforms
Not documented
Not documented
Team collaboration
Not documented
Not documented
AI features
Not documented
Not documented
Public API
Yes
Yes
Key Differences
Security Lifecycle Stage
Clair: Static, pre-deployment analysis of container image contents.
Falco: Real-time, runtime monitoring of running hosts, containers, Kubernetes, and cloud services.
A complete container security posture needs both pre-deployment scanning and runtime detection, since each catches different classes of risk.
Analysis Method
Clair: Parses image contents (manifests, packages) without executing the container, matching against continuously ingested vulnerability data.
Falco: Uses eBPF to observe live Linux kernel events with low overhead.
Static parsing vs. live kernel-level observation are fundamentally different detection techniques suited to different threats.
Ecosystem Integration
Clair: Powers vulnerability scanning behind the Quay container registry and is typically consumed via API or an integrated registry rather than a standalone UI.
Falco: Deploys via an official Helm chart to Kubernetes distributions (GKE, EKS, AKS) and forwards alerts to 50+ SIEM/data lake integrations.
Teams need to know how each tool plugs into existing registry and cluster infrastructure.
Alerting & Notification
Clair: Includes a notification service that alerts when new vulnerabilities are found affecting previously indexed images.
Falco: Generates real-time streaming JSON alerts for automated response pipelines.
Clair's alerts are retrospective (new CVEs affecting old images), while Falco's are live behavioral alerts — a full program needs both signal types.
Governance
Clair: Distributed via GitHub and built on the ClairCore library, without CNCF graduation status documented.
Falco: CNCF-graduated project under The Linux Foundation, originally created by Sysdig.
CNCF graduation signals a maturity/governance bar that some enterprise buyers use as a procurement filter.
Feature-by-Feature
Detection Approach
Feature
Clair
Falco
Static image vulnerability scanning
Available
Unavailable
Runtime behavioral anomaly detection
Unavailable
Available
eBPF-based monitoring
Unavailable
Available
Vulnerability database matching
Available
Unavailable
Coverage & Deployment
Feature
Clair
Falco
Kubernetes-native deployment (Helm chart)
Not documented
Available
Distribution/package coverage
Available
Not documented
Multi-architecture support (x64/ARM)
Not documented
Available
Self-hosting required
Available
Available
Ecosystem & Governance
Feature
Clair
Falco
Notification/alerting service
Available
Available
Third-party integrations
Not documented
Available
CNCF graduated status
Not documented
Available
Used by a named production platform
Available
Available
Pricing Compared
Starting price reflects the lowest paid tier, not the full cost for every team size or usage level.
Clair
Open Source — Free N/A
Falco
Open Source — Free N/A
Pros & Cons
Clair
Pros
Free and open source under Apache 2.0
Proven at scale as the scanning engine behind Quay.io
Broad coverage across major Linux distributions and language ecosystems
Flexible deployment options, including air-gapped environments
Cons
No official managed cloud version; requires self-hosting and operational investment
Setup and datastore management require DevOps/security engineering expertise
No built-in dashboard for non-technical users beyond what integrating tools provide
Best experienced when paired with a registry like Quay rather than used fully standalone
Falco
Pros
Completely free and open source under Apache 2.0, with no vendor lock-in or usage limits
CNCF graduated status backed by an independent security audit and multi-vendor governance
Large, active community with an extensive default rule library and plugin ecosystem
Low runtime overhead with driver options that support a wide range of kernel versions and node configurations
Cons
Linux-only kernel-level monitoring, so it cannot directly protect Windows or macOS workloads
Default rules require tuning to reduce false positives in most production environments
Detection-only by design; blocking or in-kernel enforcement requires pairing it with a separate tool like Falco Talon or Tetragon
Self-hosting the full pipeline, including alert routing and dashboards, takes real operational effort unless paired with a managed commercial platform
Use Cases
Choose Clair: Clair fits teams wanting free, self-hosted static vulnerability scanning integrated into a registry or CI/CD pipeline before images are deployed, as used by the Quay container registry, supporting Ubuntu, Debian, RHEL, SUSE, Oracle, Alpine, Amazon Linux, VMware Photon, and Python packages.
Choose Falco: Falco fits platform and security teams wanting free, CNCF-graduated runtime threat detection across hosts, containers, and Kubernetes with low-overhead eBPF monitoring and 50+ integrations to forward alerts to SIEM tooling.
Need both: A DevSecOps team implementing a shift-left-plus-runtime security strategy would naturally run both — using Clair to scan container images for known vulnerabilities before they're deployed (e.g., in CI/CD or via a registry like Quay), then running Falco to monitor those same containers for abnormal runtime behavior once deployed to Kubernetes, since pre-deployment scanning and runtime detection are complementary, not competing, layers of container security.
Clair
Container registry security scanning — Acting as the scanning backend for a private or public container registry, continuously checking stored images for known CVEs.
CI/CD pipeline security gates — Scanning images during the build pipeline to catch known-vulnerable packages before deployment.
Falco
Kubernetes runtime threat detection — Monitors syscalls and Kubernetes audit events across clusters to catch container escapes, unexpected shell access, and privilege escalation as they happen.
Compliance and audit logging — Produces a continuous, queryable record of privileged and anomalous system activity that supports PCI-DSS, SOC 2, and GDPR audit requirements.
Cloud account anomaly detection — Uses source plugins to ingest AWS CloudTrail, Okta, and GitHub audit logs into the same rules engine used for host and container detection.
Frequently Asked Questions
Do Clair and Falco do the same job?
No — Clair statically scans container images for known vulnerabilities before deployment, while Falco monitors running systems for abnormal behavior at runtime.
Are both free?
Yes, both are fully free and open source with no licensing fees.
Which one does Quay use?
Clair is used as the vulnerability scanner behind the Quay container registry.
Which is CNCF graduated?
Falco is a CNCF-graduated project under The Linux Foundation; CNCF status is not documented for Clair.
Does either require self-hosting?
Yes — both require self-hosting and operational setup, with no official managed or hosted SaaS offering documented from either project.
Can Clair and Falco be used together?
Yes, they're commonly complementary — Clair for pre-deployment image scanning and Falco for post-deployment runtime detection, covering different stages of the container lifecycle.