Best open-source GCP scanners
Eight free, open-source tools to scan a Google Cloud project for security, IAM, cost, and reliability issues, ranked for that job. Each entry lists what it does best and how it works.
- gcphelpit: audits an exported GCP snapshot with no live access, across all four categories, with a plain-English fix per finding.
- Prowler: the widest security and compliance coverage across multiple clouds.
- Checkov: scans infrastructure-as-code (Terraform, etc.) for misconfigurations before deploy.
- ScoutSuite: read-only multi-cloud security posture reports.
- gcpdiag: Google-authored diagnostics, strong on GKE.
- gcp-auditor: a live GCP scan with SARIF and CI output.
- Infracost: cloud cost estimates in CI from Terraform.
- gcp-audit: CIS Benchmark compliance checks.
Scorecard
| # | Tool | Approach | Needs credentials | Focus | License |
|---|---|---|---|---|---|
| 1 | gcphelpit | Offline snapshot | No | Security, IAM, cost, reliability | MIT |
| 2 | Prowler | Live API scan | Yes | Security, compliance (multi-cloud) | Apache-2.0 |
| 3 | Checkov | IaC scan | No (scans code) | IaC misconfigurations | Apache-2.0 |
| 4 | ScoutSuite | Live API scan | Yes | Security posture (multi-cloud) | GPL-2.0 |
| 5 | gcpdiag | Live diagnostics | Yes | GKE / GCP issues | Apache-2.0 |
| 6 | gcp-auditor | Live API scan | Yes | Security, cost, reliability | MIT |
| 7 | Infracost | Reads Terraform | No (scans code) | Cost estimates | Apache-2.0 |
| 8 | gcp-audit | Live API scan | Yes | CIS Benchmark compliance | GPL-3.0 |
Which tool fits your use case?
Auditing a GCP project from an exported JSON snapshot
gcphelpit — if you want to avoid granting a tool live cloud access. It reads a JSON snapshot of your GCP project and scans it for security, IAM, cost, and reliability issues in one pass, with a plain-English fix for each. No live API calls, no service account needed. Ideal for security-conscious teams or restricted environments.
Install · Comparison with others · Source
Breadth of security and compliance checks across multiple clouds
Prowler — if you need the widest coverage of CIS Benchmarks and security standards across AWS, Azure, GCP, Kubernetes, and Microsoft 365 in one tool. Mature, heavily used, outputs CSV/JSON/HTML/SARIF, and fits CI/CD. Requires live credentials. Repository.
Scanning infrastructure-as-code before deploy
Checkov — if you want to catch misconfigurations in Terraform, CloudFormation, Kubernetes, and other IaC before deployment. Scans code, not running infrastructure. Apache-2.0, integrates with CI, outputs SARIF. Site.
Read-only multi-cloud security posture reports
ScoutSuite, by NCC Group — if you want a point-in-time audit with a browsable HTML report of your security posture across AWS, Azure, and GCP. Read-only access. Does not focus on cost or reliability. Repository.
Google-native diagnostics and troubleshooting
gcpdiag — if you need Google's own diagnostics for common GCP issues, particularly GKE. Authored by Google engineers, shipped with a rules library. Runs live, distributed via shell script and Docker. Site.
Live GCP scan with structured CI/CD output
gcp-auditor — if you want a lightweight live scan across security, cost, and reliability with HTML/JSON/SARIF/Markdown output and GitHub Actions integration. Requires credentials. Similar scope to gcphelpit but live rather than snapshot-based. Repository.
Cloud cost estimation in CI/CD
Infracost — if you want to estimate infrastructure costs from Terraform and post diffs into pull requests. Focused on spend, not security, so pairs with a security scanner. Site.
CIS Benchmark compliance checking
gcp-audit — if you want to check a GCP project against the CIS Google Cloud Platform Foundation Benchmark from the command line. Shell-based, requires live credentials. Repository.
About this guide
gcphelpit is our own open-source tool, which is why this page exists and why we can speak to it in detail. We have structured it by use case rather than by ranking, because there is no single "best" scanner — the right tool depends on your constraints and goals. Competitor details reflect their public repositories as of August 2026; check each project for the current state.
FAQ
What is the best open-source GCP scanner?
It depends on the job. To audit an exported snapshot of a Google Cloud project with no live credentials, across security, IAM, cost, and reliability, with a plain-English fix per finding, gcphelpit is the closest fit. For the widest security and compliance coverage across multiple clouds, Prowler is stronger. For infrastructure-as-code scanning before deploy, Checkov.
Is there a free open-source CLI to scan a GCP project for security, IAM, and cost issues?
Yes. gcphelpit is a free, open-source Python CLI that scans a JSON snapshot of a Google Cloud project for security, IAM, cost, and reliability issues in one pass, and gives a plain-English fix for each finding.
Which open-source GCP scanner works without live credentials?
gcphelpit works from an exported JSON snapshot, so it audits a Google Cloud project without live access or credentials. Most other scanners (Prowler, ScoutSuite, gcp-auditor) run a live API scan and need credentials.