OpenCost

OpenCost is a vendor-neutral, open-source cost allocation system for Kubernetes and connected cloud infrastructure. It suits platform, finance, and engineering teams that already run Kubernetes with Prometheus and need container-level showback or chargeback without a license bill. Its strongest use is operational cost visibility; delayed billing feeds and unreconciled estimates make it a poor sole ledger for finalized cloud invoices.

Overview

OpenCost assigns infrastructure spending to Kubernetes concepts and individual containers, giving teams a practical basis for internal reporting, showback, and chargeback. It covers CPU, GPU, memory, load balancers, and persistent volumes, while also monitoring cloud resources outside Kubernetes. The vendor-neutral design is useful for organizations spanning providers rather than standardizing on one cloud's native cost console.

Allocation inside Kubernetes is real time. Cloud charges arrive when providers publish billing data, typically several hours to 24 hours later, and on-demand list prices are not reconciled with billed actuals. That distinction matters for budget reviews: OpenCost can explain usage promptly, but its cloud figures should not be treated as the final accounting record.

Key features

• Granular allocation: CPU, GPU, memory, load balancer, and persistent-volume costs can be attributed at Kubernetes and container level. This supports team or workload accountability instead of a single cluster total.
• Broad cloud coverage: Integrations span Alibaba, Amazon Web Services, Google Cloud Platform, Microsoft Azure, Open Telekom Cloud, Oracle Cloud Infrastructure, OVHcloud, Scaleway, and STACKIT. Cloud costs for on-premises clusters are not supported, although other cloud-provider costs can be configured.
• API and web interface: The API serves real-time and historical Kubernetes cost reports using on-demand prices and provider cost-and-usage reports. A web UI ships in the default installation, turning those allocations and related cloud costs into visual views without a separate front end.
• Metrics ecosystem: Listed integrations include Prometheus, Cortex, Thanos, Victoria Metrics, Grafana, and Grafana Cloud, which helps teams fit cost data into an existing observability workflow.
• AI access: The MCP server is enabled by default in deployments and lets AI agents access allocation, asset, and cloud-cost data. Teams should still account for the same reporting delays and estimate limitations when using that data.
• AWS credentials: IAM roles for service accounts use ambient credentials, so AWS secrets do not need to be stored in the configuration file.

Pricing

OpenCost costs free on its sole OpenCost plan. It is open source under the Apache 2.0 license, with no free trial because the product is already free. There are no published seat, usage, or renewal charges, but running it still requires your own Kubernetes and Prometheus infrastructure.

This is the right fit for teams willing to operate the stack themselves and wanting unrestricted access to allocation data. It is less suitable if you need a hosted service or a cloud-billing system that reconciles estimates to invoices.

Platforms

OpenCost provides an API and web UI and runs on Linux in a self-hosted deployment. A Kubernetes cluster and Prometheus are required; Helm is recommended for full functionality. The deployment model gives infrastructure teams control, but adds operational responsibility compared with a managed cost product.

Who it's for

Choose OpenCost when your organization already operates Kubernetes, needs workload-level chargeback or showback, and spans one or more supported clouds. It is particularly useful for platform teams integrating cost into Prometheus or Grafana workflows. Look elsewhere if your clusters are on premises and you need their cloud costs represented, or if finance requires provider-billed figures reconciled before reporting.

Pros and cons

Pros

• Free Apache 2.0 software avoids per-seat or subscription expense.
• Container-level allocation across compute, storage, memory, GPUs, and load balancers supports meaningful internal chargeback.
• Included UI, API, and broad provider and metrics integrations cover both dashboards and automation.
• AWS IAM roles for service accounts avoid storing cloud secrets in configuration.

Cons

• Cloud billing data can lag by several hours to 24 hours, weakening near-term invoice tracking.
• On-demand pricing is not reconciled against billed actual costs, so estimates can differ from final charges.
• Kubernetes and Prometheus are mandatory, and self-hosting shifts deployment and maintenance work to your team.
• On-premises cluster cloud costs are unsupported.

Alternatives

For a broader directory of options, see Kubernetes Cost Management Software and Cloud Cost Management Software.

• Atmosly Kubernetes Cost Optimization suits a small personal deployment: its free plan allows one cluster, one cloud account, one seat, one project, two environments, and ten applications, with a cost-recommendations view.
• KubeAdapt is worth considering when a free allowance covering the first 100 vCPUs and all features matters more than OpenCost's unrestricted open-source model.
• Krossboard is another freemium option for teams seeking a self-hosted web and API product.
• PerfectScale fits teams wanting a free tier up to 200 vCPU per month with unlimited clusters, nodes, and pods.
• CloudBolt is the alternative when a broader cloud-management platform capped at 100 resources is preferable.
• Klustercost offers open-source Kubernetes cost software under GPL-3.0.
• KubeLedger provides a free self-hosted option for internal use, with source code available and no right to sell it as a managed service.
• Podledger offers a forever-free, single-cloud community plan with basic dashboards and pod-level visibility.

Verdict

OpenCost is a strong choice for Kubernetes operators who need detailed, multi-cloud allocation and chargeback without software fees. Choose it for real-time workload visibility and an extensible API/UI; choose another product when hosted operation, on-premises cost coverage, or invoice-reconciled cloud accounting is the priority.