Sandboxer vs Freestyle

Freestyle offers real Linux VMs with full root, live forking, pause/resume that preserves memory, SSH and systemd, plus HTTPS domains routed to guest ports. It is a close peer to Sandboxer, with plans from free to $500/month and a 99.99% SLA on Enterprise. Pick Freestyle for live forking and its SLA tier; pick Sandboxer for nested KVM, a prompt API for its coding agents and plan dollars returned as machine time.

Checked against Freestyle's public docs on October 24, 2026. Sources are linked in the table and listed below.

At a glance

Sandboxer and Freestyle compared
Capability	Sandboxer	Freestyle
Isolation	microVM Cloud Hypervisor, its own kernel	full Linux VM (hypervisor not named) Docs describe real Linux VMs with full root; systemd is pid 1 on the Ubuntu base snapshots.
Full Linux with root	Ubuntu 24.04, sudo, systemd	Real Linux VMs with full root.
Docker inside	Preinstalled	Ubuntu base snapshots include Docker Engine, Compose and Buildx; the daemon starts at boot.
Nested virtualization (/dev/kvm)
Pause and resume with memory	Running processes come back	VMs can preserve memory while paused and wake when needed.
Fork a sandbox	Copy-on-write disk copy that boots fresh	Live forking; details of whether processes carry over not stated.
HTTPS URL per port	Private with a token, or public	Public HTTPS domain can route to a guest port; free subdomains.
Longest session	No limit on paid plans Auto-stop is up to 30 days or off	no maximum stated An optional idle timeout pauses VMs with no network activity; optional ttlSeconds deletes a VM after a set time.
Billing	Per second, flat rate per size Stopped sandboxes are free	vCPU + memory + storage usage (rates quoted per hour), plus monthly plan Hobby and Pro plan fees cover usage up to the plan amount. Billing granularity not stated.
GPUs
Self-host or open source
Regions	US East (Virginia) and EU Central (Finland)

= not documented publicly.

Price for one 4 vCPU, 8 GB machine

Sandboxer

$0.036/hour

Flat per-second rate for the default size

Freestyle

$0.26/hour

4 vCPU × $0.04032/h + 8 GiB × $0.0129/h (storage extra)

List prices from each provider's pricing page, before free credits, plans and storage. This compares price only.

Where Freestyle is strong

Live forking and pause/resume that preserves memory.
SSH, systemd and HTTPS domains routed to guest ports.
Free tier plus Hobby ($50) and Pro ($500) plans, with an Enterprise 99.99% SLA.
Ubuntu base snapshots ship Docker and coding agents (claude, codex, opencode, openclaw).

Where Sandboxer differs

Persistent VMs and custom sizing require Hobby or Pro; Free is non-persistent.
Max VM size is 4 vCPU/8 GiB on Free, 8/16 on Hobby, 32/64 on Pro.
Nested KVM is not documented by Freestyle; Sandboxer provides /dev/kvm in every sandbox.

Pick Freestyle if

You need an enterprise SLA and SAML/SCIM.
You want live forking with VM-level SSH and domain routing.
You need larger VMs up to 32 vCPU / 64 GiB.

Pick Sandboxer if

You need nested KVM (/dev/kvm) inside the VM.
You want coding agents driven through a prompt API with streamed events and an MCP server.
You want plan dollars to return as machine time and per-second billing.

Sources

Products change. If something here is out of date, email hello@sandboxer.com and we'll fix it. Freestyle is a trademark of its owner. Sandboxer is an independent product and is not affiliated with Freestyle.

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