Blaxel vs Unikraft Cloud
Both run each workload in a Firecracker microVM that sleeps when idle and wakes in milliseconds. Blaxel is an agent sandbox billed per active second with up to 200 at once, while Unikraft Cloud is a general microVM cloud sold as small flat pools of running capacity.
The companies and products
Blaxel
Blaxel is a San Francisco company that runs cloud infrastructure for AI agents, and since September 2026 it is part of Baseten.
You get sandboxes, batch jobs, MCP server hosting and a model gateway. Each sandbox is a Firecracker microVM with its own kernel that drops to standby when nothing is connected and resumes in under 25 ms with its memory and running processes. It is built for agent products that start many sandboxes and want them asleep most of the time.
- Headquarters
- San Francisco, founded 2024
Unikraft Cloud
Unikraft Cloud is a microVM cloud from Unikraft Inc. that runs any Dockerfile-based workload as a minimal Linux microVM with millisecond cold starts and scale-to-zero.
Your Dockerfile becomes the VM image at build time, and each instance runs on a heavily customized Firecracker VMM, so it boots in milliseconds and can go into standby when no traffic arrives. It is a general compute platform built for dense, bursty work such as HTTP services, headless browsers and agent fleets, sold as flat self-serve plans plus Enterprise dedicated hosts, on-prem and bring your own cloud. It is not a dev machine you log into: instances are reached through services, the CLI and a sandbox plugin for commands and files.
Which use cases each one fits
For each use case, Battleships prices every sandbox provider on the same workload and sorts them from the cheapest monthly bill up. “10th cheapest of 367” means 9 of the other 366 providers run that workload, with every feature it needs, for less. “With limits” means the provider runs it but misses something, so it is listed after every full match. Open a use case for its whole ranking and what each provider misses.
| Use case and its workload | Blaxel: price rank | Unikraft Cloud: price rank | bochka: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Blaxel fits a software factory with Docker inside its sandboxes, while Unikraft has no self-serve pool big enough for it; bochka adds /dev/kvm and a real disk. | 10th cheapest of 367 $2,373 a month | Can't run it | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB | 12th cheapest of 366 $2,832 a month | Can't run it | 5th cheapest of 366 $657 a month |
| Code interpreter bursts 100 at once · 1 vCPU / 2 GB · 200,000 sessions of 1 min a month Short runs that sleep right away suit both, and Blaxel can run many more at once on a self-serve tier than Unikraft's 24 running instances. | 14th cheapest of 345 $144 a month | Can't run it | 186th of 345, with limits $2,000 a month |
| Sandboxes for your users 300 at once · 2 vCPU / 4 GB · 30,000 sessions of 23 min a month Blaxel's self-serve tiers stop at 200 sandboxes at once and Unikraft Pro at 24 running ones, so 300 active users need sales on both; bochka fits them on a self-serve plan. | 101st of 361, with limits $926 a month | Can't run it | Cheapest of 361 $209 a month |
| RL rollouts 1,000 at once · 2 vCPU / 4 GB · 1,000,000 sessions of 3 min a month | 77th of 360, with limits $4,378 a month | Can't run it | 34th of 360, with limits $2,000 a month |
| Agent evals 250 at once · 4 vCPU / 8 GB · 15,000 sessions of 20 min a month | 136th of 364, with limits $704 a month | Can't run it | 10th cheapest of 364 $200 a month |
| CI runners 40 at once · 8 vCPU / 16 GB · 6,000 sessions of 12 min a month CI that builds Docker images works on Blaxel but not on Unikraft, which documents no container runtime inside; neither gives /dev/kvm on self-serve, and bochka does. | 57th cheapest of 377 $431 a month | Can't run it | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB All three can keep a box around all month: Unikraft's Team pool is $39 a month flat, Blaxel bills every active second, and bochka is a plain machine you SSH into. | 265th of 368, with limits $114 a month | 219th of 368, with limits $39 a month | 18th cheapest of 368 $26 a month |
| Computer-use agents 50 at once · 4 vCPU / 8 GB · 20,000 sessions of 15 min a month Blaxel runs a desktop and a browser for computer use, Unikraft has none built in, and bochka streams a 60fps desktop you can embed. | 14th cheapest of 369 $634 a month | Can't run it | 6th cheapest of 369 $200 a month |
| Browser-use agents 50 at once · 2 vCPU / 4 GB · 30,000 sessions of 10 min a month Blaxel gives sandboxes a browser to drive, while on Unikraft you build headless Chrome into your own image. | 16th cheapest of 367 $317 a month | Can't run it | 7th cheapest of 367 $200 a month |
| Scraping & bots (startup scale) 50 at once · 1 vCPU / 2 GB · 100,000 sessions of 3 min a month | 16th cheapest of 346 $215 a month | Can't run it | 6th cheapest of 346 $90 a month |
| Mass scraping & bots (undetectable) 1,000 at once · 1 vCPU / 2 GB · 3,000,000 sessions of 2 min a month | 147th of 338, with limits $4,292 a month | Can't run it | 71st of 338, with limits $1,800 a month |
| Parallel red teaming 200 at once · 2 vCPU / 4 GB · 5,000 sessions of 30 min a month Blaxel and bochka both fit parallel red teaming on a self-serve plan, and Unikraft's pools are too small for a fleet. | 3rd cheapest of 360 $217 a month | Can't run it | 2nd cheapest of 360 $200 a month |
| GPU eval jobs 10 at once · 8 vCPU / 32 GB · 500 sessions of 30 min a month | Can't run it | Can't run it | Can't run it |
| macOS agents 5 at once · 4 vCPU / 8 GB · 1,000 sessions of 20 min a month | Can't run it | Can't run it | Can't run it |
Key features
| Feature | Blaxel | Unikraft Cloud | bochka |
|---|---|---|---|
| Isolation | Firecracker microVM with its own kernel | Minimal Linux microVM on a customized Firecracker VMM; full VMs on Enterprise | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Machine size | Sized by RAM, with CPU included (8 GB comes with 4 cores); up to 256 GB on Custom | Plan pool shared by all running instances: 2 vCPU / 4 GiB, 8 vCPU / 8 GiB or 24 vCPU / 32 GiB | 4 vCPU / 8 GB by default, up to 16 vCPU / 32 GB per sandbox on the $100 plan and above |
| Docker and systemd inside | Docker with a Docker-in-sandbox image; no systemd | Runs as root; the Dockerfile becomes the VM image, with no container runtime inside documented | Docker, systemd and root, like any Ubuntu machine |
| Nested virtualization | No: Firecracker guests do not get /dev/kvm | Yes, with a per-instance flag and permission, Enterprise only | Yes, /dev/kvm for Android emulators and VMs on every plan |
| SSH | No native SSH; a terminal through the bl connect command | Not yet; commands and files go through the sandbox plugin and CLI | Real SSH into every sandbox |
| Desktop and browser | Desktop, browser and computer use supported | None built in; you can run your own headless browser from a Dockerfile | Linux desktop streamed at 60fps, Chromium, and a computer-use agent |
| Sleep and wake | Standby a few seconds after the last connection, wakes in under 25 ms with memory and processes; standby sandboxes count toward the concurrency limit | Standby after a 1 second idle cooldown by default, wakes on the next request in milliseconds; standby instances do not count toward the running pool | Stop keeps the disk and costs nothing; a stopped sandbox is started by API and boots again |
| Disk | Files live in memory (about half the RAM); one block volume can be attached at creation | Volumes you attach; standby storage included in the plan (8 GiB, 15 GiB or 1 TiB) | A real disk that stays, snapshotted every minute and on stop |
| Fork and checkpoints | Fork with memory and running processes (private preview) | Checkpoint memory and volumes of a running microVM with a pause of a few milliseconds, then start new instances from it | Fork a running sandbox with its disk; snapshots every minute |
| Inbound access | Preview URL per port, public or token-protected; no raw TCP or public IP | Services on its load balancer: HTTP on 80, HTTPS on 443, TLS-wrapped TCP on other ports; no public IP per instance | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP; dedicated IPv4 or IPv6 |
| Outbound rules | Domain allow and deny lists, method and path rules, static egress IPs | Network shield filters traffic, Enterprise only, limited access | Open internet; filter inside the VM with nftables |
| Keeping API keys out of the sandbox | Proxy fills secrets into outbound HTTPS requests (public preview) | Network shield can inject secrets into traffic, Enterprise only, limited access | Credentials proxy for model providers and any HTTPS API, on every plan; switch a credential to another account when credits run out |
| Coding agents | Claude Code image you drive from its terminal or your own harness | None preinstalled; you bring the agent in your own image | Seven agents preinstalled, driven from outside with a prompt, steer and events API |
| Regions | Oregon, North Virginia, London, Frankfurt | Dallas, Frankfurt, San Francisco, Singapore, Washington DC; more metros on request | EU only: Germany, Finland, France |
Every feature Battleships tracks (43)
| Feature | Blaxel | Unikraft Cloud | bochka |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | No | Yes |
| Nested virtualization | No | Yes | Yes |
| Root | Yes | Yes | Yes |
| Systemd | No | Not published | Yes |
| Desktop GUI | Yes | No | Yes |
| Browser | Yes | No | Yes |
| Computer-use API | Yes | No | Yes |
| SSH | No | No | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | Yes | Yes |
| Automatic snapshots | Yes | Yes | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | Yes | Yes | Yes |
| Memory fork | Yes | Yes | No |
| Custom image (Docker or snapshot) | Yes | Yes | Yes |
| ≥24 h sessions | Yes | Yes | Yes |
| Idle auto-stop | Yes | Yes | No |
| Wake on request | Yes | Yes | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | No | Not published | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | Yes | Yes | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | Yes | Yes | Yes |
| Preinstalled agents | Yes | No | Yes |
| Agent harness API | No | No | Yes |
| MCP server | Yes | No | No |
| GPU | No | Yes | No |
| Windows | No | No | No |
| Arm64 | No | Yes | No |
| Self-hosting | No | Yes | No |
| BYOC | Yes | Yes | No |
| Open source | No | No | No |
| Scoped API keys | Yes | Not published | Yes |
| Spend limits | No | Not published | Yes |
| Usage per sandbox (API) | Yes | No | Yes |
| Audit logs | Not published | Yes | No |
| SSO | Yes | No | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | Yes | Yes | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Yes | Not published | Yes |
Performance
In the same hpc-sandbox-benchmarks Node.js build-and-test run at 4 vCPU / 8 GB on September 29, 2026, bochka did 26.69 runs per second and Blaxel 19.48, so bochka got through about 1.4 times the work in the same time. Unikraft Cloud has no comparable measurement: it was not in that run, and its stated cold starts under 10 ms measure start time, not CPU speed.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Blaxel measured on: Sandbox (active time, RAM-only pricing, CPU bundled). Unikraft Cloud has no published run in this suite yet, so there is no like-for-like number to compare.
Pricing in five scenarios
Each bill is priced from the providers' public price lists by the open Battleships engine, with the cheapest plan that runs the scenario.
| Scenario | Blaxel, a month | Unikraft Cloud, a month | bochka, a month |
|---|---|---|---|
| One coding agent, workdays 4 vCPU / 8 GB, 50 GB disk, 8 hours a day, 22 days a month, files kept between days | $33 · Pay-as-you-go Tier 1 | $39 · Hobby | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $120 · Pay-as-you-go Tier 1 | $39 · Hobby | $26 · $20/mo |
| 50 agents in parallel 50 machines of 4 vCPU / 8 GB at once, 8-hour sessions, 1,100 sessions a month, Docker inside | $1,489 · Pay-as-you-go Tier 1 | Can't run it | $317 · $20/mo × 3 seats |
| Sandboxes for your users 2 vCPU / 4 GB, 30,000 sessions of 10 minutes a month, up to 300 at once | $396 · Pay-as-you-go Tier 2 · with limits | Can't run it | $200 · $100/mo × 2 seats |
| 1,000 short jobs at once 2 vCPU / 4 GB, 1,000 at once, 3 minutes each, 200,000 jobs a month | $876 · Pay-as-you-go Tier 2 · with limits | Can't run it | $2,000 · $2000/mo · with limits |
Blaxel: Blaxel charges for allocated RAM per second while a sandbox is active, with CPU included. In standby you pay only snapshot storage, and volumes are billed on their full size.
Unikraft Cloud: Unikraft charges a flat monthly fee for a pool of running capacity: free for 2 vCPU / 4 GiB, $39 for 8 vCPU / 8 GiB and $199 for 24 vCPU / 32 GiB. It publishes no per-hour rate, so anything bigger is an Enterprise quote.
Unikraft Cloud: Plans start at $20 a month, and the whole fee is usage credit. You pay per second while a sandbox runs, and a stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Unikraft's limits are pools that every running instance shares: one 4 vCPU / 8 GB agent fills the Team pool's memory, so the 50-agent, user-sandbox and burst scenarios fit no self-serve plan. Blaxel fits 50 agents, but its tiers allow 10, 50 or 200 sandboxes at once with standby ones counted, so 300 users or 1,000 jobs at once need a sales tier, and Tier 0 and 1 delete sandboxes after 7 or 30 days. bochka runs 100 to 2,000 sandboxes at once on its plans, but it limits starts per minute, so 1,000 jobs at the same moment get queued.
| Scenario | Blaxel | Unikraft Cloud | bochka |
|---|---|---|---|
| One coding agent, workdays | None that bite |
| None that bite |
| One agent that never stops | None that bite |
| None that bite |
| 50 agents in parallel | None that bite |
| None that bite |
| Sandboxes for your users |
|
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Blaxel when
you build an agent product that starts many sandboxes, wants Docker, a browser and network rules inside them, and needs them asleep most of the time.
- Fleets of agent sandboxes, self-serve. For agent products that start many sandboxes: self-serve tiers run up to 200 at once, billed per active second.
- Agent tools out of the box. For teams that want Docker inside, a desktop and browser, a Claude Code image and a secret proxy without building images first.
- Network rules without a contract. For locked-down agents: domain allow lists, method and path rules and static egress IPs, where Unikraft keeps egress filtering for Enterprise.
Use Unikraft Cloud when
you run a few small services or headless browsers that sleep most of the time on a flat fee, need Singapore or more US metros, or want GPUs, on-prem or your own cloud under Enterprise.
- A flat fee for small, steady work. For one small service or agent that runs all month: the Team pool is a flat $39, and sleeping instances do not count.
- Regions in the US and Asia. For users far from Europe and the US coasts: Dallas, San Francisco, Washington DC and Singapore as well as Frankfurt.
- GPUs, arm64 and your own hardware. For Enterprise buyers who need NVIDIA GPUs, arm64 hosts, nested virtualization, dedicated hosts, on-prem or their own cloud.
Where bochka fits
Blaxel and Unikraft Cloud are both built around microVMs that sleep in seconds and wake in milliseconds. If your agents instead work for hours on builds, tests, Docker and emulators, bochka gives each one a whole Linux machine with a real disk, a faster CPU than Blaxel measured, and the agents already installed.
A whole machine the agent can work in
bochka has Docker, systemd, SSH and /dev/kvm on every plan. Blaxel has no /dev/kvm or native SSH, and Unikraft documents no container runtime inside, has no SSH yet and keeps nested virtualization for Enterprise.
Big fleets of full-size sandboxes
Fifty 4 vCPU / 8 GB agents fit bochka's self-serve plans. Unikraft's biggest pool holds 24 running instances on 32 GiB in total, and Blaxel's tiers stop at 200 at once with sleeping sandboxes counted.
Agents and keys built in
Seven coding agents come installed, driven from outside through one API, and real keys stay in a credentials proxy. On Blaxel you build the harness yourself and the secret proxy is in preview; on Unikraft both need your own image or Enterprise.
Use bochka when your agents need a real machine to work in for hours: Docker, emulators, SSH, a desktop, a faster CPU, agents driven from outside, and fleets without a sales call. Compare it one to one: bochka vs Blaxel and bochka vs Unikraft Cloud.
Questions people ask
Is Blaxel cheaper than Unikraft Cloud?
For one agent on workdays Blaxel is a little cheaper ($33 against $39), and for one that never stops Unikraft's flat Team pool wins ($39 against $120 on Blaxel). For 50 agents in parallel Blaxel costs $1,489 a month, while no self-serve Unikraft plan is big enough. bochka costs $20, $26 and $317 for those three.
Which is faster, Blaxel or Unikraft Cloud?
For CPU work only Blaxel has a comparable measurement: 19.48 runs per second at 4 vCPU / 8 GB, against 26.69 for bochka. Both wake from standby in milliseconds, and Unikraft states cold starts under 10 ms.
Can Blaxel or Unikraft Cloud run Docker?
Blaxel can, with its Docker-in-sandbox image. Unikraft uses your Dockerfile to build the VM itself and documents no container runtime inside a running instance. A bochka sandbox has Docker, systemd and /dev/kvm ready to use.
Can I SSH into Blaxel or Unikraft Cloud?
Neither has native SSH today. Blaxel gives you a terminal through bl connect, and Unikraft runs commands and moves files through its sandbox plugin and CLI. You can SSH into every bochka sandbox.
Can I run an Android emulator on either?
An emulator needs /dev/kvm. Blaxel's Firecracker guests do not get it, and Unikraft offers nested virtualization only on Enterprise. bochka exposes /dev/kvm inside every sandbox on every plan.
Is bochka SOC 2 compliant?
SOC 2 is in progress. We're open about where we stand: live status at status.bochka.xyz and our data retention policy at docs.bochka.xyz/data-retention.
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