Sandboxer vs HopX

HopX is a cloud sandbox service for AI agents that runs code in isolated microVMs with dedicated kernels, with pause/resume, public preview URLs per port and VNC desktop automation. The main difference is pricing and packaging: HopX bills per second for vCPU, memory and storage with no subscription, while Sandboxer sells fixed sizes on a monthly plan and preinstalls Docker, nested KVM, SSH and coding agents. Pick HopX for pay-as-you-go code execution or desktop automation without a plan; pick Sandboxer for full Ubuntu VMs that coding agents work in for long stretches.

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

At a glance

Sandboxer and HopX compared
Capability	Sandboxer	HopX
Isolation	microVM Cloud Hypervisor, its own kernel	microVM Site describes 'isolated microVMs' and 'hardware-level isolation with dedicated kernels'; hypervisor not named.
Full Linux with root	Ubuntu 24.04, sudo, systemd	Docs show shell commands and Ubuntu templates but do not state root/sudo access.
Docker inside	Preinstalled	Custom templates are built from Docker images; running Docker inside a sandbox is not documented.
Nested virtualization (/dev/kvm)
Pause and resume with memory	Running processes come back	pause() preserves full state including memory; resume continues where it left off.
Fork a sandbox	Copy-on-write disk copy that boots fresh	No sandbox fork/clone documented; custom templates serve as starting images.
HTTPS URL per port	Private with a token, or public	'HopX automatically exposes all ports'; get_preview_url returns a public URL for any port.
Longest session	No limit on paid plans Auto-stop is up to 30 days or off	no default limit; optional timeout A timeout can be set and extended; when it expires the sandbox is destroyed. Maximum not stated.
Billing	Per second, flat rate per size Stopped sandboxes are free	per second: vCPU + memory + storage $0.000014/vCPU-s, $0.0000045/GiB-s RAM, $0.00000003/GiB-s storage; no subscription; $200 free credits.
GPUs		The template API lists a 'gpu' feature flag, but GPU availability and pricing are not documented.
Self-host or open source
Regions	US East (Virginia) and EU Central (Finland)	us-east, eu-west (examples) Region selection shown with 'eu-west' or 'us-east' as examples; full list not published.

= not documented publicly.

Price for one 4 vCPU, 8 GB machine

Sandboxer

$0.036/hour

Flat per-second rate for the default size

HopX

$0.33/hour

4 vCPU × $0.000014/s × 3600 = $0.2016 + 8 GiB × $0.0000045/s × 3600 = $0.1296; total $0.3312/h, before storage ($0.00000003/GiB-s)

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

Where HopX is strong

Sandboxes are isolated microVMs with dedicated kernels that HopX says start in about 100 ms.
Pause keeps full memory state and resume picks up where the sandbox left off.
Pure per-second pay-as-you-go pricing with no subscription and $200 of free credits.
Built-in desktop automation: VNC, screenshots, screen recording, mouse and keyboard control.

Where Sandboxer differs

HopX bills per vCPU-second and GiB-second with no plan; Sandboxer charges fixed hourly sizes inside a monthly plan that comes back as machine time.
HopX sets sandbox resources from the template; Sandboxer picks from four fixed sizes at create time.
Sandboxer documents root, Docker preinstalled, nested KVM and SSH in every VM; HopX docs do not state these.
HopX documents a desktop automation API (VNC, mouse, keyboard); Sandboxer's facts list no desktop API.

Pick HopX if

You want pay-per-second sandboxes with no monthly commitment.
Your agent needs to drive a GUI desktop through an API.
You run many short code-execution calls from an LLM app.

Pick Sandboxer if

You need Docker and nested KVM inside the sandbox, with root and SSH.
You want coding agents (Claude Code, Codex, OpenCode and others) preinstalled and driven by a prompt API.
You want a predictable fixed price per size: $0.036/h for 4 vCPU / 8 GB.

Sources

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

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