We have deployed ArgoCD and Flux across dozens of client environments over the past three years. Some of those clusters are running regulated healthcare workloads. Others are startup MVPs with four engineers and a single node pool. The question we hear most often is simple: which one should we pick?
The honest answer is that neither tool is universally better. But after running both in production — through upgrade cycles, incident post-mortems, and the Weaveworks shutdown — we have formed strong opinions backed by data. This post lays out everything we have learned so our readers can make a confident decision.
What GitOps actually changes in Kubernetes delivery
Before diving into the tooling, it is worth establishing what GitOps means in practice versus traditional DevOps. GitOps is not simply “CI/CD with Git.” It is an operating model where:
- Desired state is declared in Git (Kubernetes manifests, Helm values, Kustomize overlays).
- A controller reconciles the live cluster to match that declared state continuously.
- Every change is reviewable and attributable through pull requests, approvals, and commit history.
The shift is subtle but significant: deployment responsibility moves from a pipeline running kubectl apply to a continuously running reconciler that detects drift, self-heals, and enforces consistency. Both ArgoCD and Flux implement this pull-based model, but their architectures diverge sharply.
ArgoCD in 60 seconds
ArgoCD is a declarative, GitOps continuous delivery tool for Kubernetes maintained under the Argo project at CNCF. It graduated from the CNCF in December 2022.
ArgoCD ships as a monolithic application comprising an API server, a repository server, an application controller, Dex for SSO, and Redis for caching. Its standout feature is a rich web UI that lets teams visualise application topology, trigger syncs, inspect diffs, and roll back deployments without touching the command line.
With over 17,800 GitHub stars and a growing ecosystem of community plugins, ArgoCD has become the default choice for organisations prioritising developer experience and visual management.
Flux in 60 seconds
Flux is a GitOps engine built entirely around Kubernetes controllers. It also graduated from the CNCF in November 2022 and is categorised as “Adopt” on the CNCF CI/CD Tech Radar.
Unlike ArgoCD’s monolithic approach, Flux follows a modular controller-based design known as the GitOps Toolkit. Each responsibility is handled by a dedicated controller: the Source Controller fetches manifests, the Kustomize Controller applies overlays, the Helm Controller manages chart releases, the Notification Controller dispatches alerts, and the Image Automation Controller handles container tag promotion.
With 6,500 GitHub stars and 150+ contributors, Flux has a smaller but intensely active community. Everything is defined as a Custom Resource Definition (CRD) and reconciled through Kubernetes-native loops — there is no central API server or built-in dashboard.
Architecture deep-dive: how they actually work
Understanding the architectural differences is critical because they dictate operational trade-offs around resource usage, scalability, and day-two maintenance.
ArgoCD: the monolithic GitOps engine
ArgoCD renders manifests first — whether they originate as Helm charts, Kustomize bases, or plain YAML — and then applies them using its internal GitOps Engine. The application controller maintains a full in-memory graph of every managed resource, which powers the real-time UI but also means memory consumption scales with the number of tracked Kubernetes objects.
ArgoCD supports SyncWindows, which act as scheduled maintenance windows controlling when auto-syncs are permitted. It also offers selective syncs, allowing teams to apply changes to specific resources rather than the entire application. This flexibility is valuable during development cycles but introduces operational concepts that do not exist in vanilla Kubernetes.
Flux: the modular controller toolkit
Flux splits the GitOps pipeline across independent controllers, each running as a static binary and tracking only its own objects. This design keeps memory footprints small and allows each component to be upgraded or replaced independently.
The reconciliation philosophy is deliberately opinionated: Flux continuously drives the cluster toward the declared state in Git. If someone makes a manual change, Flux detects the mismatch and reverts it. The main controls are to suspend or enable reconciliation, with sync intervals configurable per resource rather than globally.
Reconciliation philosophy compared
ArgoCD gives operators more manual levers — UI-triggered syncs, selective resource targeting, and the option to run a diff without applying changes. Flux takes a stricter stance: the system continuously reconciles, and local drift is always corrected. For teams that want GitOps to be an absolute guarantee of consistency, Flux’s approach is philosophically purer. For teams that need occasional manual intervention, ArgoCD’s flexibility is practical.
Head-to-head feature comparison
The following table summarises the feature differences we encounter most frequently in client engagements. For a deeper look at how these tools integrate into a complete GitOps, Helm, and ArgoCD delivery stack, see our dedicated playbook.
| Feature | ArgoCD | Flux |
|---|---|---|
| Web UI | Built-in rich dashboard with topology view | No built-in UI; use Weave GitOps, Grafana, or third-party dashboards |
| Helm support | Native, strong community adoption | First-class via dedicated Helm Controller |
| Kustomize support | Supported as a config management plugin | First-class via dedicated Kustomize Controller |
| Multi-cluster management | Native central control plane; single UI for all clusters | Each cluster runs its own Flux instance; coordination via Git |
| RBAC | Built-in fine-grained RBAC with Projects | Relies on Kubernetes-native RBAC |
| SSO integration | Native via Dex (Auth0, Google, Microsoft, Okta, Zitadel) | No native SSO; depends on cluster-level identity providers |
| Secrets management | External Secrets Operator or Vault integration | Native SOPS integration for encrypted secrets in Git |
| Image automation | Requires separate ArgoCD Image Updater | Native image-automation-controller |
| Rollback | One-click rollback via UI or CLI | Automated rollback via Helm Controller |
| Progressive delivery | Argo Rollouts (Canary, Blue-Green, analysis runs) | Flagger (Canary, A/B, Blue-Green) |
| Notifications | Built-in since v2.6 | Dedicated Notification Controller |
| Sync intervals | Global sync interval | Per-resource sync intervals |
| Drift detection | Visual diff in UI | Automatic correction |
| Resource footprint | Higher (API server + UI + controller + Redis) | Lower (lightweight static binary controllers) |
| Air-gapped support | Supported | Strong support; designed for isolated environments |
| ApplicationSet | Native multi-app templating across clusters | Kustomize overlays for similar patterns |
| Audit logging | Built-in event logs and change history | Kubernetes-native events |
Secrets management: a practical difference
Flux’s native SOPS integration allows teams to store encrypted secrets directly in Git. Configure it once, and decryption happens automatically in the cluster. This enables a complete “GitOps-only” approach even for passwords and API keys, which aligns well with teams that want a single source of truth without external dependencies.
ArgoCD does not support SOPS natively. Most teams pair it with External Secrets Operator or HashiCorp Vault. This is not necessarily a disadvantage — for organisations already running Vault, the integration is seamless — but it does add a component to the stack. For more context on managing sensitive data in Kubernetes, see our guide on Kubernetes secrets security mistakes to avoid.
Image automation: Flux’s hidden strength
One of Flux’s most underappreciated capabilities is automated image promotion. The image-automation-controller scans container registries, evaluates tag policies (for example, SemVer 1.0.*), and automatically patches YAML in the Git repository when a new matching tag appears. The change flows through Git, is reconciled to the cluster, and produces a complete audit trail.
ArgoCD achieves similar functionality through the ArgoCD Image Updater, but it is a separate component that must be installed and configured independently.
Progressive delivery: Argo Rollouts vs Flagger
Both ecosystems support advanced deployment strategies beyond basic rolling updates.
Argo Rollouts integrates deeply with ArgoCD and provides Canary releases, Blue-Green deployments, and automated analysis runs that query metrics providers before promoting traffic. It is the more mature option with stronger community adoption.
Flagger, the Flux ecosystem’s progressive delivery controller, supports Canary, A/B testing, and Blue-Green strategies. It integrates with service meshes like Istio and Linkerd, as well as ingress controllers like NGINX and Contour.
Both are production-ready. Our preference leans toward Argo Rollouts when teams are already invested in the ArgoCD ecosystem, and Flagger when Flux is the primary GitOps engine.
The numbers: adoption, community, and scale
2025 CNCF End User Survey
The 2025 CNCF End User Survey provides the most authoritative adoption data available:
- 60% of reported Kubernetes clusters use ArgoCD for application delivery
- 97% of respondents use ArgoCD in production, up from 93% in 2023
- 42% manage 500+ applications per ArgoCD instance
- 37% of users identify as platform engineers
- ArgoCD achieved a Net Promoter Score (NPS) of 79, indicating strong satisfaction
- 60% have been using ArgoCD for more than two years
The CNCF survey did not produce equivalent granular data for Flux, which is itself telling. ArgoCD’s adoption lead is substantial and growing.
GitHub and community metrics
| Metric | ArgoCD | Flux |
|---|---|---|
| GitHub stars | 17,800+ | 6,500 |
| CNCF status | Graduated (Dec 2022) | Graduated (Nov 2022) |
| Primary backing | Intuit, Red Hat, Codefresh/Akuity, AWS | ControlPlane, Microsoft Azure, GitLab, Cisco |
| Community plugins | Extensive ecosystem | Smaller but focused |
Resource consumption at scale
In our benchmarking across client environments, ArgoCD consumes roughly twice the CPU and memory of Flux during initial synchronisation. This gap narrows during steady-state reconciliation but remains meaningful.
The reason is architectural: ArgoCD maintains a full application graph in memory and runs an API server plus Redis alongside the controller. Flux’s controllers are static binaries that each track only their own objects.
For edge clusters, cost-constrained staging environments, or organisations running Kubernetes on limited node pools, Flux’s lighter footprint is a genuine advantage. For teams that want to understand the cost implications, our guide on Kubernetes cost optimisation strategies covers the broader picture.
Scalability benchmarks
- ArgoCD: Tested to 50,000 applications and 1,000 connected clusters (with UI list pagination enabled). UI slowdowns are reported at 3,000-5,000 applications without tuning. ApplicationSets reduce multi-cluster deployment cycles from 30+ minutes to approximately 5 minutes — an 83% reduction.
- Flux: Documented scaling guides support “tens of thousands” of applications per installation. Lean memory usage means scaling is primarily constrained by Kubernetes API server capacity rather than Flux itself.
Enterprise readiness scorecard
For organisations evaluating these tools against enterprise procurement criteria, we maintain the following scorecard based on our consulting engagements.
SSO and authentication
ArgoCD wins decisively here. It ships with native SSO via Dex, supporting Auth0, Google, Microsoft, Okta, and Zitadel out of the box. Local users can be added through a ConfigMap, and team-based RBAC policies can restrict who can sync, view, or delete applications.
Flux has no native SSO. Access control relies entirely on Kubernetes RBAC, which is powerful but requires teams to manage identity at the cluster level rather than the application level. For organisations with mature Kubernetes RBAC audit practices, this is workable. For teams starting from scratch, ArgoCD’s built-in access management is significantly easier to adopt.
Audit logging
ArgoCD generates detailed event logs and tracks application change history within its data store. However, centralised logging is not provided out of the box — teams still need ELK, Loki, or a similar stack for aggregation and analysis.
Flux relies on Kubernetes-native events, which integrate with whatever logging infrastructure is already in place. Neither tool provides a turnkey audit solution for compliance teams, but ArgoCD’s application-level event history is more granular.
Multi-cluster management
ArgoCD’s centralised model allows a single installation to manage 10, 50, or over 100 clusters from one interface. The ApplicationSet controller enables templated deployments across clusters using generators (Cluster, Git, List, and more), and the App of Apps pattern provides hierarchical management of complex environments.
Flux requires a separate installation in each cluster, with coordination handled through Git. This is operationally simpler in some ways — there is no central control plane to protect — but it lacks the unified visibility that ArgoCD provides. For teams managing large EKS estates, our EKS architecture best practices guide covers how ArgoCD fits into production-ready cluster designs.
Cloud provider managed offerings
Cloud providers have begun offering managed GitOps services, and the landscape here is shifting rapidly:
- AWS EKS: Fully managed ArgoCD capability (GA November 2025; see section below)
- Azure AKS: Native Flux GitOps extension
- GitLab: Continued Flux integration commitment
The split is notable: AWS has bet on ArgoCD, while Microsoft has backed Flux. This does not prevent either tool from running on any cloud, but managed offerings reduce operational burden considerably.
The elephant in the room: Flux’s future after Weaveworks
Weaveworks shut down in February 2024. The company — which created Flux, coined the term “GitOps,” and served as the project’s primary sponsor — ceased operations after a promising acquisition fell through at the final stage.
This raised immediate questions about Flux’s sustainability. At the time of shutdown, most core Flux maintainers were employed by Weaveworks. The community responded with tangible support: ControlPlane stepped in to employ core maintainers, Microsoft Azure, Edgecell, Cisco, and GitLab all pledged backing.
As of early 2026, Flux remains actively maintained with a published 2025 roadmap and regular releases. Its stable and beta APIs are well tested and safe for production use.
However, we advise clients to consider this context honestly. Flux’s long-term sustainability depends on community funding rather than a single large commercial backer. For risk-averse organisations — particularly those in regulated industries — this is a factor worth weighing against Flux’s technical merits. The CNCF governance model provides structural stability, but day-to-day maintenance requires funded maintainers.
Our position: Flux is production-ready today and will remain so for the foreseeable future. But organisations choosing Flux should do so with eyes open about the governance model, and should have a contingency plan — which, realistically, means ArgoCD migration readiness.
AWS EKS managed ArgoCD: a game changer
At AWS re:Invent 2025, Amazon announced the general availability of EKS Capabilities, a set of fully managed Kubernetes-native platform features. One of the three launch capabilities is continuous deployment with ArgoCD.
What makes this significant:
- Fully managed: ArgoCD runs in AWS-managed service accounts outside the customer’s cluster. AWS handles scaling, patching, upgrades, and inter-cluster communications.
- Native integrations: Built-in support for AWS Secrets Manager, Amazon ECR, AWS CodeCommit, and AWS CodeConnections.
- No operational overhead: Teams get enterprise-grade GitOps without maintaining ArgoCD infrastructure.
- Availability: All AWS Regions except GovCloud and China.
For teams already running on EKS, this eliminates one of ArgoCD’s historical drawbacks — the operational burden of managing the ArgoCD stack itself. The AWS Prescriptive Guidance for GitOps tools provides a detailed comparison of ArgoCD and Flux in the EKS context.
This development is one of the strongest signals yet that ArgoCD is becoming the de facto standard for Kubernetes GitOps, particularly in AWS environments.
Decision framework: which tool fits your team
Rather than offering vague guidance, here are specific criteria we use with clients.
Choose ArgoCD when:
- Your team is new to GitOps and needs a visual interface for learning and troubleshooting. The UI dramatically lowers the onboarding curve.
- Developer experience is a priority. ArgoCD’s dashboard, one-click rollbacks, and real-time sync status make it easy to demo, teach, and observe.
- You manage applications across multiple clusters and need a single pane of glass. ArgoCD’s centralised model and ApplicationSets excel here.
- Your organisation requires SSO, fine-grained RBAC, and audit trails without bolting on additional tools.
- You are running on AWS EKS and want to leverage the fully managed ArgoCD capability.
- Community size and ecosystem maturity matter to your procurement process.
Choose Flux when:
- You are a platform engineering team building repeatable, modular infrastructure patterns. Flux’s controller-based design maps cleanly to platform engineering golden paths.
- Resource constraints are real — edge clusters, cost-sensitive staging environments, or small node pools where every megabyte of memory matters.
- Native secrets management via SOPS is a requirement, and you want encrypted secrets stored directly in Git without external dependencies.
- Automated image promotion is a core workflow, and you prefer it built in rather than added as a separate component.
- Your team prefers Kubernetes-native, CRD-first workflows and is comfortable operating entirely through the CLI.
- You are running on Azure AKS and want to leverage the native Flux GitOps extension.
- Air-gapped or network-isolated environments are part of your deployment topology.
Consider a hybrid approach when:
Some large organisations use Flux for infrastructure-level reconciliation (Terraform state, cluster addons, CNI configuration) and ArgoCD for application delivery. This pattern leverages Flux’s lightweight footprint and per-resource sync intervals for platform concerns, while giving application teams ArgoCD’s UI and RBAC.
We have seen this work well at organisations with distinct platform and application teams. However, it adds significant operational complexity — two GitOps engines to maintain, monitor, and upgrade. We recommend this approach only for organisations with mature platform engineering practices and clear team boundaries.
Real-world migration lessons
GetYourGuide migrated from Spinnaker to ArgoCD and shared several production lessons worth noting:
- They accidentally deleted application namespaces during migration but recovered within an hour. They subsequently implemented a validation webhook to prevent namespace deletion unless explicitly labelled.
- Multiple services using Argo Rollouts generated excessive API calls to Datadog, hitting rate limits.
- The team contributed 35+ pull requests to upstream ArgoCD and Rollouts projects, all promptly reviewed and accepted — a testament to community health.
- ArgoCD’s internal components proved robust with no breaking changes across upgrades, unlike their previous Spinnaker experience.
The key takeaway for any migration: run both systems in parallel during the transition, migrate incrementally, and thoroughly test each converted application before decommissioning the old tool.
Getting started: from zero to GitOps
For teams ready to begin, both tools have mature installation paths.
ArgoCD can be installed via a single kubectl apply of its manifests or through Helm. The official documentation walks through setup in under 15 minutes. For AWS users, the EKS managed capability eliminates installation entirely. Our ArgoCD migration guide covers the broader adoption journey.
Flux is bootstrapped via the flux CLI, which installs all controllers and configures the Git repository connection. The Flux getting started guide is equally straightforward.
In both cases, the real work begins after installation: structuring Git repositories, defining application boundaries, configuring RBAC policies, and establishing promotion workflows across environments. This is where experienced guidance pays for itself many times over.
Ship GitOps with Confidence Across Your Kubernetes Fleet
Choosing between ArgoCD and Flux is only the first step. The real challenge is designing a GitOps architecture that scales across environments, enforces security policies, and integrates with your existing CI/CD pipelines without introducing operational drag.
Our team provides comprehensive ArgoCD consulting and GitOps implementation services to help you:
- Design multi-cluster GitOps architectures using ApplicationSets, App of Apps patterns, and environment promotion workflows
- Migrate from legacy deployment tools (Jenkins, Spinnaker, manual kubectl) to pull-based GitOps with zero downtime
- Implement enterprise governance including SSO, RBAC, audit logging, and secrets management tailored to your compliance requirements
We have deployed ArgoCD and Flux across regulated healthcare environments, high-scale e-commerce platforms, and startup infrastructure — and we bring those lessons directly to your team.