Best microVM platforms in 2026, ranked (Firecracker, Cloud Hypervisor and others)
Updated October 24, 2026 .md
Short answer: For a hosted microVM you can treat as a whole Linux machine, we rank Sandboxer (Cloud Hypervisor) first, then E2B and AWS Lambda MicroVMs (Firecracker), all of which keep memory across a pause. Pick Unikraft Cloud for millisecond scale-to-zero, Northflank for bring-your-own-cloud, and self-hosted Firecracker or microsandbox to run microVMs yourself.
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 is a microVM?#
A microVM is a lightweight virtual machine: a minimal virtual machine monitor (such as Firecracker or Cloud Hypervisor) runs a guest with its own Linux kernel on hardware virtualization such as KVM. It keeps most of a VM's isolation with much less overhead than a traditional VM. That is why sandbox and serverless platforms use microVMs for untrusted or AI-generated code. For the two monitors most platforms here use, see Firecracker vs Cloud Hypervisor; for why the boundary matters, see Container vs microVM.
How to compare microVM platforms#
- A documented microVM per workload: the platform says each instance is its own microVM.
- Pause with memory: a paused instance comes back with its memory and running processes.
- A full machine: root, systemd and Docker inside, rather than a single process.
- Session length: no short platform cap on how long an instance runs.
- Price: a published price for a 4 vCPU, 8 GB machine-hour.
- Hosted: managed services rank above tools you run yourself (microsandbox and self-hosted Firecracker are listed last).
We apply the criteria in this order; later ones break ties.
Comparison table#
| # | Platform | Isolation | Resume keeps running processes | Docker / full Linux | Nested KVM | 4 vCPU / 8 GB, per hour | Checked |
|---|---|---|---|---|---|---|---|
| 1 | Sandboxer | microVM (Cloud Hypervisor, its own kernel) | Yes | Yes | Yes | $0.036 | 2026-10-24 |
| 2 | E2B | microVM | Yes | Partly | No | $0.33 | 2026-10-15 |
| 3 | AWS Lambda MicroVMs | Firecracker microVM | Yes | Yes | Not documented | $0.50 | 2026-10-24 |
| 4 | Unikraft Cloud | microVM per instance (hardware-level isolation) | Yes | Partly | Not documented | — | 2026-10-24 |
| 5 | Northflank Sandboxes | microVM on Cloud Hypervisor (gVisor for GPU sandboxes) | Not documented | Yes | Not documented | $0.13 | 2026-10-24 |
| 6 | Fly.io Sprites | microVM (hardware-isolated) | Partly | Yes | Not documented | $0.33 | 2026-10-24 |
| 7 | Docker Sandboxes | microVM (hypervisor) | Not documented | Yes | Not documented | — | 2026-10-24 |
| 8 | Vercel Sandbox | microVM | No | Partly | Not documented | $0.68 | 2026-10-15 |
| 9 | Cloudflare Sandbox | microVM per container instance (docs: each instance has its own kernel) | No | Partly | Not documented | $0.36 | 2026-10-24 |
| 10 | Deno Sandbox | Linux microVM | Not documented | Not documented | Not documented | — | 2026-10-24 |
| 11 | microsandbox | microVM (libkrun) | Yes | Partly | Not documented | — | 2026-10-24 |
| 12 | Self-hosted Firecracker | Firecracker microVM (KVM) | Yes | Partly | Not documented | — | 2026-10-24 |
"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 platforms, 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: a whole Linux machine per microVM. Each sandbox is a Cloud Hypervisor microVM running Ubuntu 24.04 with root, systemd, Docker and /dev/kvm (nested virtualization), an HTTPS URL for any port and a public IPv6 address. Stopping saves memory and device state, and a stopped sandbox costs nothing.
Where others win: no GPUs, hosted only, and no SLA during early access.
2. 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: open-source Firecracker sandboxes. Pause keeps memory and running processes, fork makes running copies, and the stack is Apache-2.0 with Terraform for your own AWS or GCP account.
Where it's weaker for this use: sessions are capped per plan.
3. AWS Lambda MicroVMs#
At a glance (source: AWS Lambda MicroVMs docs, checked 2026-10-24): isolation: Firecracker microVM · resume keeps processes: Yes · longest session: 8 hours per MicroVM, not adjustable · price: $0.50/hour · full comparison and sources.
Best for: teams on AWS. Firecracker microVMs built from your Dockerfile image, with suspend and resume that keep memory and disk and no compute charge while suspended, lifecycle hooks, and egress through your own VPC.
Where it's weaker for this use: each MicroVM is limited to 8 hours, and that limit can't be changed.
4. Unikraft Cloud#
At a glance (source: Unikraft Cloud docs, checked 2026-10-24): isolation: microVM per instance (hardware-level isolation) · resume keeps processes: Yes · longest session: Not documented · price: No 4 vCPU / 8 GB list price · full comparison and sources.
Best for: many small, bursty services. Unikraft Cloud documents Firecracker microVMs with cold starts under 10 ms, millisecond scale-to-zero, millisecond resume of stateful apps, VM forking and checkpoints, and hosted, dedicated, BYOC and on-prem options.
Where it's weaker for this use: it runs Dockerfile images, but a Docker daemon inside isn't documented, nor are root or session length.
5. Northflank Sandboxes#
At a glance (source: Northflank Sandboxes docs, checked 2026-10-24): isolation: microVM on Cloud Hypervisor (gVisor for GPU sandboxes) · resume keeps processes: Not documented · longest session: no limit · price: $0.13/hour · full comparison and sources.
Best for: bring-your-own-cloud and GPUs. Cloud Hypervisor microVMs (gVisor for GPU workloads), sandboxes that run until you delete them, and deployment into your own cloud.
Where it's weaker for this use: whether a pause keeps memory isn't documented.
6. 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: persistent microVMs that cost almost nothing while idle, with checkpoints and an always-on HTTPS URL.
Where it's weaker for this use: after a longer idle period the in-memory state is dropped.
7. 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: microVMs on your own laptop, free: Docker's sbx CLI gives each agent a microVM with a private Docker daemon, with a cloud option on Docker-managed infrastructure.
Where it's weaker for this use: cloud sandboxes expire after one hour by default.
8. Vercel Sandbox#
At a glance (source: Vercel Sandbox docs, checked 2026-10-15): isolation: microVM · resume keeps processes: No · longest session: see comparison · price: $0.68/hour · full comparison and sources.
Best for: apps on Vercel: Firecracker microVMs with active-CPU billing, many regions and VPC peering.
Where it's weaker for this use: resume doesn't keep running processes.
9. Cloudflare Sandbox#
At a glance (source: Cloudflare Sandbox docs, checked 2026-10-24): isolation: microVM per container instance (docs: each instance has its own kernel) · resume keeps processes: No · longest session: no fixed limit stated · price: $0.36/hour · full comparison and sources.
Best for: apps on Cloudflare Workers; each container instance runs in its own microVM, billed in 10 ms steps of active time.
Where it's weaker for this use: no resume with memory.
10. Deno Sandbox#
At a glance (source: Deno Sandbox docs, checked 2026-10-24): isolation: Linux microVM · resume keeps processes: Not documented · longest session: 30 minutes per session; extendable · price: No 4 vCPU / 8 GB list price · full comparison and sources.
Best for: short code-execution jobs from JavaScript or Python: Linux microVMs that Deno says start in under 200 ms, with volumes and filesystem snapshots, and two regions.
Where it's weaker for this use: sessions are 30 minutes (extendable), and its snapshots are filesystem-only in the docs we read.
11. microsandbox#
At a glance (source: microsandbox docs, checked 2026-10-24): isolation: microVM (libkrun) · resume keeps processes: Yes · longest session: Not documented · price: No 4 vCPU / 8 GB list price · full comparison and sources.
Best for: embedding microVMs in your own app or running them locally: open source (Apache-2.0), libkrun microVMs, full snapshots of memory and processes, and copy-on-write fork.
Where it's weaker for this use: it's beta software, its hosted cloud isn't priced yet, and locally you run and operate it yourself.
12. Self-hosted Firecracker#
At a glance (source: Self-hosted Firecracker docs, checked 2026-10-24): isolation: Firecracker microVM (KVM) · resume keeps processes: Yes · longest session: no limit · price: No 4 vCPU / 8 GB list price · full comparison and sources.
Best for: building your own platform with full control. Firecracker is open source (Apache 2.0), with snapshot and resume of memory and device state, on your own x86_64 or aarch64 hardware.
Where it's weaker for this use: you build everything around it yourself: networking, images, a public URL per port and an API.
Running microVMs yourself vs a hosted platform#
Running Firecracker or Cloud Hypervisor yourself gives you full control and no platform fees. It also means you build and operate the parts a hosted platform provides:
- host provisioning with KVM;
- networking and egress filtering (Firecracker's docs say guest egress "should be filtered at the host-level");
- images, snapshots and their storage;
- per-port HTTPS routing;
- an API and SDKs.
Choose self-hosting when you have the engineering time, or a hard requirement for your own data centre.
How we tested#
We read each platform's own docs and pricing pages, recorded what they state with a date, and had a second reviewer check each claim against its source. We didn't benchmark other platforms. Sandboxer's own numbers, measured by us on 2026-10-24 over 10 runs from a client with a 27 ms round trip (conditions and results): ready in 3.19–3.20 s, resume with memory in 1.34–1.37 s, process kept its PID in 10 of 10 runs (script).
Which should you choose?#
- A whole Linux machine per microVM, kept in memory across pauses: Sandboxer.
- Open source: E2B (hosted or in your cloud), microsandbox or self-hosted Firecracker (on your own machines).
- You run on AWS: AWS Lambda MicroVMs.
- Bursty services that scale to zero in milliseconds: Unikraft Cloud.
- Your own cloud or GPUs: Northflank.
- Free, on your laptop: Docker Sandboxes.
FAQ#
What is the difference between a microVM and a container?#
A container shares the host's kernel and is isolated with namespaces and cgroups. A microVM runs its own kernel behind hardware virtualization, which is a stronger boundary for untrusted code. See Container vs microVM.
Which platforms use Firecracker?#
E2B, Vercel Sandbox, AWS Lambda MicroVMs and Unikraft Cloud document Firecracker. Sandboxer and Northflank use Cloud Hypervisor, and microsandbox uses libkrun.
Which microVM platforms keep memory when paused?#
Sandboxer, E2B, AWS Lambda MicroVMs, Unikraft Cloud and microsandbox document pause, suspend or snapshots with memory. Self-hosted Firecracker supports memory snapshots, which you wire up yourself.
Can I run Docker inside a microVM?#
Yes, if the platform gives you a full Linux guest. On Sandboxer, Docker is preinstalled in every sandbox; Docker Sandboxes gives each agent a private Docker daemon. See Docker and nested KVM in an agent sandbox.
Should I build my own microVM platform?#
Only if you need full control or your own hardware and have the time to build networking, images, snapshots and an API around Firecracker or Cloud Hypervisor. Otherwise a hosted platform is faster to adopt.
Related#
More guides
For running AI-written code we rank Sandboxer, Freestyle and E2B first: each gives code its own VM with an API or SDK and can pause with memory. Pick Daytona for Windows or GPUs, Modal or Northflank for GPUs at scale, E2B or Northflank to run in your own cloud, and Vercel Sandbox if your app lives on Vercel.
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.
The best Daytona alternatives depend on why you're switching. For a full Linux microVM on every sandbox with memory-saving stop and Docker, we rank Sandboxer first. E2B suits open source and self-hosting, Modal massive short-job fleets, Northflank bring-your-own-cloud with GPUs, and Vercel Sandbox apps on Vercel.
If you're leaving E2B for longer sessions or a fuller machine, we rank Sandboxer first, then Freestyle: both give each sandbox a full Linux VM that keeps memory across pauses, with Docker and no short session cap. Pick Daytona for Windows or GPUs, Northflank for bring-your-own-cloud, and stay on E2B if you need open source.