Spacelift vs env0 vs Atlantis — IaC Automation Compared

Once your Terraform footprint grows past a handful of state files, running plan and apply from laptops stops working. You want plans on every pull request, policy checks before anything touches production, and someone watching for drift. Three tools dominate that space: Spacelift, env0, and Atlantis. They solve the same problem from very different angles, and the right pick depends more on your team shape than on any feature checklist.

Here's how they actually compare when you run them day to day. For the broader landscape, see our best Infrastructure-as-Code tools guide.

Hosting model #

Spacelift: SaaS-first. You point it at your VCS and cloud accounts and it runs everything on managed workers, though you can attach self-hosted worker pools inside your network for private resources. There's a self-hosted enterprise edition, but the common path is their cloud.

env0: Also SaaS-first, with the same self-hosted-agent option so runs execute against private networks while the control plane stays managed. No open-source core.

Atlantis: Self-hosted open-source, full stop. You run a Go binary (usually a container) somewhere reachable by your Git provider's webhooks. There is no SaaS Atlantis. That single fact drives most of the trade-offs below.

Policy-as-code #

This is where Spacelift pulls ahead. Policies are written in Rego (Open Policy Agent) and attach at defined points: plan, apply, login, task, notification, and more. You can block an apply based on the plan's resource changes, not just the code that produced it.

rego.rego

# Deny any plan that destroys an RDS instance in production
package spacelift

deny[msg] {
resource := input.terraform.resource_changes[_]
resource.type == "aws_db_instance"
resource.change.actions[_] == "delete"
input.spacelift.stack.labels[_] == "env:production"
msg := sprintf("blocked: deleting RDS %s in production", [resource.address])
}

env0: Uses OPA as well, wired through its approval-policy system, plus native cost and TTL guardrails. Solid, though less granular than Spacelift's per-phase model.

Atlantis: Has policy_check mode built on conftest (also OPA/Rego), so you can gate plans on policy. It works, but you assemble and maintain the plumbing yourself rather than getting a managed policy library.

Pricing model #

Spacelift: Free tier for small use, then per-user plus per-concurrent-worker pricing. Costs scale with team size and how much parallel run capacity you need.

env0: Also seat-based on paid tiers with a free starter tier. Its cost and TTL controls are a selling point for teams trying to keep cloud spend down.

Atlantis: The software is free. Your cost is the compute you run it on plus the engineering time to operate it, patch it, and keep it available. That's rarely zero, but it's predictable and has no per-seat component, which matters a lot at 50-plus engineers.

Drift detection #

Spacelift: Scheduled drift detection is a first-class feature. It periodically runs plans, flags stacks that no longer match state, and can auto-remediate by applying.

env0: Ships continuous drift detection with notifications and optional auto-remediation, configurable per environment.

Atlantis: No native drift detection. Teams bolt it on with a cron job that runs terraform plan and pipes results somewhere, or add a separate tool like driftctl. It's doable, but it's your project, not a checkbox.

Multi-IaC support #

Spacelift: The broadest. Terraform, OpenTofu, Pulumi, CloudFormation, Ansible, and Kubernetes manifests all run as native stack types.

env0: Terraform, OpenTofu, Terragrunt, Pulumi, CloudFormation, and custom flows. Strong coverage, especially if you live in Terragrunt.

Atlantis: Terraform and OpenTofu focused, with Terragrunt via a wrapper. It does the Terraform workflow extremely well and doesn't pretend to be a general orchestrator.

Workflow and PR integration #

All three center on the pull request, and all three post plan output as PR comments and gate the merge on approval.

Atlantis is the purest expression of the model: open a PR, it comments the plan, you type atlantis apply in the thread, it applies and reports back. Nothing else in the UI to learn.

Spacelift and env0 add web UIs, run history, RBAC, stack dependencies, and notification routing on top of the same PR loop. If you want an audit trail and a dashboard for non-Terraform-fluent stakeholders, the managed tools give you that out of the box.

Ephemeral environments #

env0 owns this category. It's built around spinning up a full environment from a PR, tagging it with a TTL, and destroying it automatically when the PR merges or the timer expires. If your workflow is "every feature branch gets a real, disposable copy of the stack," env0 makes that a configuration rather than a scripting project.

Spacelift supports the pattern too through stack templates and hooks, but it's less turnkey. Atlantis has no built-in concept of ephemeral, TTL-bound environments; you'd script the create-and-destroy lifecycle yourself.

Self-hosting cost, honestly #

Atlantis being free is real, but "free" is the license, not the operation. You own uptime, webhook reachability, the state backend, secrets handling, upgrades, and the on-call when the runner wedges mid-apply. For a team that already runs infrastructure competently, that overhead is small and the control is worth it. For a team that would rather not babysit another service, the seat cost of Spacelift or env0 buys back that time.

Who each is for #

Spacelift: Platform teams that want serious, phase-level policy-as-code, the widest IaC support, and managed drift detection. The strongest choice when governance is the priority and you're standardizing many teams onto one control plane.

env0: Teams that live and die by ephemeral environments and cost guardrails, especially heavy Terragrunt users. Pick it when self-service, TTLs, and spend control are the point.

Atlantis: Teams that want a free, self-hosted, PR-driven Terraform workflow and are comfortable running the service. Ideal for smaller or infra-savvy orgs that value control and zero per-seat cost over managed convenience.

Making the decision #

Ask three questions in order:

Do you want to run the service yourself? If no, Atlantis is out, and you're choosing between Spacelift and env0. If you're happy operating it and want zero seat cost, Atlantis is a strong finalist.

Is your defining need governance or ephemeral environments? Governance and broad policy leans Spacelift. Disposable per-PR environments and cost controls lean env0.

How many IaC tools do you actually run? Pure Terraform or OpenTofu keeps all three in play. A mix of Pulumi and CloudFormation pushes you toward Spacelift.

If you're specifically migrating off HashiCorp's managed offering, our Terraform Cloud alternatives piece covers that angle in more depth.

The call we'd make #

For most growing platform teams, we'd start with Spacelift. The per-phase OPA policies and native drift detection solve the two problems that actually hurt as you scale (ungoverned applies and silent drift), and the broad IaC support means you won't outgrow it when someone inevitably adds Pulumi.

If ephemeral environments are your core workflow, go env0 without hesitation; nothing else makes that pattern as effortless. And if you're a lean, infra-competent team that wants a free, transparent, PR-native flow and doesn't mind owning a container, Atlantis is still the honest answer and will happily run for years. Match the tool to your team, not to the feature grid, and any of the three will hold up.