Best sandboxes for running coding agents (Claude Code, Codex, Gemini CLI) in 2026, ranked

Short answer: For coding agents we rank Sandboxer first: a full Ubuntu VM with Claude Code and Codex preinstalled, Docker, and stop-and-resume that keeps the agent's session in memory. Freestyle and Amp Orbs also keep memory across pauses. Pick E2B for prebuilt agent templates on open source, Docker Sandboxes for free local runs, and Codespaces if you live in GitHub.

Published by Sandboxer, and we're on this list. We ranked by the criteria below and say where others are the better choice. Every fact about another platform comes from its own docs or pricing page, checked on the date shown; follow each name for the full comparison and sources.

What a coding agent needs from a sandbox#

Claude Code, Codex, Gemini CLI and similar agents work like a developer: they clone a repository, install dependencies, run builds and tests, start dev servers and sometimes Docker. Running them unattended, especially with permission prompts off, is only safe on a machine that holds nothing else. See Run Claude Code without permission prompts, safely.

How to compare them#

1. A whole machine. Root, systemd and Docker, so the agent can install anything and run services.
2. Isolation. Its own VM and kernel, not a container sharing a host.
3. The session survives a pause. Whether a paused machine comes back with the agent's process and the dev server still running.
4. Long runs. No short platform cap on a session.
5. Driving the agent. Agents preinstalled, or an API to prompt and follow them, so you're not just renting a shell.
6. Cost while idle. What you pay while the agent waits for you.
7. Self-serve. You can sign up and start today without a sales process.

Comparison table#

"Not documented" means the platform's public docs don't say. Prices are list prices for one 4 vCPU, 8 GB machine-hour; a dash means the platform doesn't sell that size by the hour or doesn't publish a price for it.

The sandboxes, ranked#

1. Sandboxer#

At a glance (source: our docs and pricing): isolation: microVM (Cloud Hypervisor, its own kernel) · resume keeps processes: Yes · longest session: No limit on paid plans · price: $0.036/hour.

Best for: running Claude Code, Codex or other agents unattended for hours, several at once. Every sandbox is a Cloud Hypervisor microVM with Ubuntu 24.04, root, systemd and Docker. Claude Code, Codex, OpenCode, Pi, Kimi Code and Mistral Vibe are preinstalled and can be prompted, followed and steered over the CLI or API (sbx prompt, sbx events, sbx steer). Stopping saves memory, so the agent's session, tmux and the dev server are still running after resume; a stopped sandbox costs nothing. Gemini CLI isn't preinstalled; install it in the VM with npm install -g @google/gemini-cli.

Where others win: no GPUs, no self-hosting, and the integrated agents need your own API keys (subscription sign-in for them is coming).

2. Freestyle#

At a glance (source: Freestyle docs, checked 2026-10-24): isolation: full Linux VM (hypervisor not named) · resume keeps processes: Yes · longest session: no maximum stated · price: $0.26/hour · full comparison and sources.

Best for: live forking of a running agent's VM. Freestyle provides full Linux VMs with pause and resume that preserves memory, live forking, SSH and HTTPS domains per port, and its base snapshots include Claude Code, Codex and OpenCode.

Where it's weaker for this use: the hypervisor isn't named in its docs.

3. E2B#

At a glance (source: E2B docs, checked 2026-10-15): isolation: microVM · resume keeps processes: Yes · longest session: see comparison · price: $0.33/hour · full comparison and sources.

Best for: an open-source sandbox with prebuilt agent templates. E2B offers Claude Code and Codex templates that you run as commands, Firecracker microVMs whose pause keeps memory and processes, and Terraform to run it in your own cloud.

Where it's weaker for this use: sessions are capped per plan, and Docker comes from a template rather than being preinstalled.

4. Docker Sandboxes#

At a glance (source: Docker Sandboxes docs, checked 2026-10-24): isolation: microVM (hypervisor) · resume keeps processes: Not documented · longest session: cloud: 1 hour by default · price: No 4 vCPU / 8 GB list price · full comparison and sources.

Best for: running agents on your own laptop for free. Docker's sbx CLI runs coding agents in microVM sandboxes with a private Docker daemon each, working in your local project directory, with a host-side proxy that keeps credentials out of the VM. A cloud option runs on Docker-managed infrastructure.

Where it's weaker for this use: cloud sandboxes expire after one hour by default.

5. exe.dev#

At a glance (source: exe.dev docs, checked 2026-10-24): isolation: VM (own VMM process per VM) · resume keeps processes: Not documented · longest session: Not documented · price: $0.21/hour · full comparison and sources.

Best for: many persistent VMs on one flat monthly pool, or regions outside the US. exe.dev VMs are reachable over SSH as root and have HTTPS URLs by default, with nine regions.

Where it's weaker for this use: whether a paused VM keeps its memory isn't documented.

6. Amp Orbs#

At a glance (source: Amp Orbs docs, checked 2026-10-24): isolation: Not documented · resume keeps processes: Yes · longest session: no run limit stated; pauses when idle · price: $0.33/hour · full comparison and sources.

Best for: teams already using the Amp coding agent. Orbs are remote Debian machines where Amp works on a thread; pausing saves memory and disk, so terminals and dev servers are still running when it wakes, and Portals give shareable URLs for dev servers with review comments sent back to the agent.

Where it's weaker for this use: it's built around Amp rather than any agent you choose, and the isolation type isn't documented.

7. Daytona#

At a glance (source: Daytona docs, checked 2026-10-15): isolation: container or VM · resume keeps processes: Partly · longest session: see comparison · price: $0.33/hour · full comparison and sources.

Best for: teams that need Windows or GPU environments alongside Linux, or SDKs in Ruby, Go or Java. Daytona's VM sandboxes can pause with memory preserved.

Where it's weaker for this use: memory-saving stop and VM isolation depend on which sandbox class you pick.

8. Fly.io Sprites#

At a glance (source: Fly.io Sprites docs, checked 2026-10-24): isolation: microVM (hardware-isolated) · resume keeps processes: Partly · longest session: no maximum stated · price: $0.33/hour · full comparison and sources.

Best for: agents that work in bursts. Sprites are persistent microVMs with checkpoints, an always-on HTTPS URL, and no compute charge while idle.

Where it's weaker for this use: after a longer idle period the in-memory state is dropped, so a running agent process doesn't always survive.

9. Claude Managed Agents#

At a glance (source: Claude Managed Agents (Anthropic) docs, checked 2026-10-24): isolation: Linux container on Anthropic-managed infrastructure · resume keeps processes: Not documented · longest session: Not documented · price: No 4 vCPU / 8 GB list price · full comparison and sources.

Best for: letting Anthropic run the Claude agent loop for you. The runtime (in beta) runs Claude in per-session Linux containers with many languages, Chromium and Playwright preinstalled, built-in tools and event streaming.

Where it's weaker for this use: it's Claude only, runs in containers rather than VMs, and you don't get a machine you keep.

10. GitHub Codespaces#

At a glance (source: GitHub Codespaces docs, checked 2026-10-24): isolation: container on a VM · resume keeps processes: Not documented · longest session: 12 h maximum lifetime; idle timeout 30 min default, up to 240 min · price: No 4 vCPU / 8 GB list price · full comparison and sources.

Best for: work that lives in GitHub and uses devcontainer.json, with free monthly hours on personal accounts.

Where it's weaker for this use: a codespace has a 12-hour maximum lifetime and runs as a container on a VM.

11. Ona#

At a glance (source: Ona docs, checked 2026-10-24): isolation: VM per environment · resume keeps processes: Not documented · longest session: Not documented · price: No 4 vCPU / 8 GB list price · full comparison and sources.

Best for: enterprises that need environments inside their own AWS or GCP VPC, defined as Dev Containers with org-wide guardrails.

Where it's weaker for this use: its docs say new customer sign-up is closed, and its site describes Ona as part of OpenAI.