Costย Estimatesย forย YourCloudย Infrastructure
before you deploy
Open source CLI for Terraform, Terragrunt, and CloudFormation with optimization recommendations, budget guardrails, and fully offline mode. No API key required.
Join 100+ engineers already using c3x. Founding pricing for the first 100 seats. No spam, unsubscribe anytime.
Watch C3X work
The whole flow in one short walkthrough: point C3X at a Terraform project and see the cost, before you apply.
Prefer YouTube? Open the demo in a new tab.
Works with your infrastructure stack
Real Output, Not Mockups
What you actually see when you run C3X on a Terraform project.
From Zero to Cost Visibility
Three steps. No account required. Works with any Terraform project.
Install
One command. Works on macOS, Linux, Windows, and Docker. No account required.
Estimate
Point at your Terraform project. Get a full cost breakdown in seconds.
Optimize
Get actionable suggestions: newer instance types, better storage, architecture improvements.
Cost on Every Pull Request
Add one step to your workflow. Every pull request gets a comment with what the change does to the monthly bill, updated on each push.
- The change versus the base branch, not just a total
- Fails the check when a PR adds more than your budget
- No API key, no secrets: it uses the job token
steps:
- uses: actions/checkout@v5
- uses: c3xdev/c3x@v0
with:
path: .
# fail if a PR adds > $50/mo
budget-delta: "50"
c3x-cloudbotcommentedC3X cost estimateEstimate details
Posted as c3x-cloud[bot] when the C3X Cloud app is installed and the workflow grants id-token: write; otherwise by github-actions.
Everything You Need to Manage Cloud Costs
From cost estimation to optimization recommendations, budget enforcement, and offline mode.
278 Priced Resource Kinds
Across AWS, Azure, and Google Cloud, out of 1,361 recognized; the rest are free and reported as $0. Terraform, Terragrunt, and CloudFormation. Usage-based resources like Lambda and S3 priced via usage files.
Learn moreCost Recommendations
Suggests newer instance generations, gp2 to gp3 migrations, VPC endpoints for NAT Gateway, and more. Runs locally, no cloud subscription.
Learn moreBudget Guardrails
Every PR gets a comment with the cost change vs the base branch. Gate with --budget on the total or --budget-delta on the increase. Free, no paid subscription required.
Learn moreWhat-If Scenarios
Test cost impact of changes without modifying Terraform code. --what-if lets you override any resource attribute on the fly.
Learn moreFully Offline
Download pricing data once with c3x pricing sync. Then estimate without any network calls. Perfect for air-gapped environments.
Learn moreSelf-Hosted Pricing
Independent pricing API that scrapes directly from AWS, Azure, and GCP. No vendor lock-in. Your data stays on your infrastructure.
Learn moreHow C3X Compares
An honest look at how C3X stacks up against other Terraform cost estimation tools.
| Feature | C3X | Infracost |
|---|---|---|
| Open source CLI | Client only | |
| No API key required | ||
| Fully offline mode | ||
| Self-hosted pricing API | Free | Discontinued |
| Budget guardrails (CLI) | --budget flag | Paid |
| Cost recommendations | Free | Paid |
| What-if scenarios | --what-if flag | |
| AWS resources priced | 115 | 103 |
| Azure resources priced | 112 | 149 |
| GCP resources priced | 51 | 57 |
| Terragrunt support | ||
| CloudFormation | Free | |
| PR comments | Free | 1k runs/mo |
| Actively maintained |
Verified against each vendor's public documentation on 23 September 2026. Counts are resource kinds that produce a non-zero cost; every tool here also recognizes a much larger set of always-free kinds and each counts those differently. Suggest a correction
Before & After C3X
See how teams transform their cloud cost management from reactive firefighting to proactive optimization.
Without C3X
- Surprise cloud bills after deployment
- Manual spreadsheet estimation
- No cost gate in CI/CD pipelines
- Vendor lock-in to proprietary pricing APIs
With C3X
- See the cost of a change before you merge
- Automatic optimization suggestions
- Budget guardrails in every pipeline
- Fully offline, own your data
Fits Into Your Workflow
Works with the IaC tools and CI/CD platforms you already use.
Where We're Going
The open-source CLI is here today. A hosted product is being shaped with the people on the waitlist.
Phase 1 Open Source CLI
- Cost estimation for 278 priced resource kinds (1,361 recognized)
- Optimization recommendations
- Budget guardrails for CI/CD
- What-if cost scenarios
- Fully offline mode
- Self-hosted pricing API
Phase 2 C3X Cloud
An optional hosted product, separate from the free CLI. We're using the waitlist to decide what it should include. Ideas we're exploring:
- Multi-project cost dashboard
- Historical cost tracking over time
- Team cost allocation views
- Comparing estimates to real cloud bills
- Scheduled cost reports
Get early access to C3X Cloud
The CLI is free, open source, and here today, and it stays free. C3X Cloud is a separate, optional hosted product we're exploring. Join the waitlist to help shape what it includes, with early access and founding pricing.
C3X Cloud
An optional hosted product, separate from the free CLI. We're using the waitlist to decide what it should include. Ideas we're exploring:
- Multi-project cost dashboard
- Historical cost tracking over time
- Team cost allocation views
- Comparing estimates to real cloud bills
- Scheduled cost reports
Join 100+ engineers already using c3x. Founding pricing for the first 100 seats. No spam, unsubscribe anytime.
Frequently Asked Questions
Everything you need to know about C3X.
Start Estimating in
30 Seconds
One command to install. Point at your Terraform project. See costs instantly.
Also available via Docker:
docker pull ghcr.io/c3xdev/c3x