Replit vs Unikraft Cloud
Replit is an AI app builder: you describe an app, Replit Agent writes it, and Replit hosts it. Unikraft Cloud is a microVM cloud: your own Dockerfile becomes a tiny VM that boots in milliseconds and sleeps when traffic stops.
The companies and products
Replit
Replit is an AI app builder and hosting platform: you describe an app in chat, Replit Agent writes it, and Replit publishes it.
You work in a browser workspace where Replit Agent sets up the project, writes the code, tests it and fixes problems, with system packages managed by Nix. When the app is ready you publish it as an Autoscale, Static, Scheduled or Reserved VM deployment, with Postgres and object storage next to it. It is built for people and teams who want a working app, not for programs that need to create many machines by API, so this page compares the parts where the two overlap.
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. “181st cheapest of 367” means 180 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 | Replit: 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 A software factory starts many agents from code; Replit drives only Replit Agent through its MCP server, and Unikraft documents no Docker inside its microVMs. | 181st of 367, with limits $2,000 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 An always-on assistant is a Reserved VM app billed all month on Replit, and a share of an 8 GiB Team pool on Unikraft Cloud. | 202nd of 366, with limits $2,033 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 code runs that sleep between calls fit Unikraft's wake-on-request design, while Replit's Autoscale is a web host that scales to zero, not a code runner. | 228th of 345, with limits $146 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 Neither fits 300 sandboxes for your users as is: Replit does not publish how many deployments run at once, and Unikraft Pro runs only 24 instances. | 233rd of 361, with limits $825 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 | 258th of 360, with limits $4,226 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 | 265th of 364, with limits $685 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 jobs that build containers need Docker inside; neither Replit nor Unikraft Cloud documents it, and bochka has it on every machine. | 275th of 377, with limits $425 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 A 24/7 box is the only use case where both are ranked: about $39 a month for the Unikraft Team pool and $109 on Replit, against $26 on bochka. | 165th of 368, with limits $109 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 Replit's VNC pane shows a desktop to a person, Unikraft has no desktop built in, and bochka streams one at 60fps with a computer-use agent. | 190th of 369, with limits $619 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 On Unikraft you bake your own headless browser into the image; Replit has no browser API for agents; bochka gives each sandbox Chromium on a desktop. | 229th of 367, with limits $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 | 234th of 346, with limits $217 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 | 150th of 338, with limits $4,378 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 | 208th of 360, with limits $215 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 | Replit | Unikraft Cloud | bochka |
|---|---|---|---|
| Kind of product | AI app builder with browser workspaces and app hosting | MicroVM cloud that runs any Dockerfile-based workload | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Not documented; the security page says strong logical separation between users | Minimal Linux microVM per instance on a customized Firecracker VMM | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Creating machines from code | MCP server tools to create, update and publish apps; no API to start many machines | CLI, JS SDK and a sandbox plugin for commands and files | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker and systemd inside | System packages come from Nix; Docker and systemd are not described | 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 | Not described in the docs | Yes, with a per-instance flag, Enterprise only | /dev/kvm on every plan, for Android emulators and VMs |
| SSH | Into the workspace on paid plans | Not yet; commands and files go through the sandbox plugin and CLI | Into every sandbox |
| Coding agents | Replit Agent, which an MCP client can also drive | None preinstalled; you bring the agent in your own image | Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API |
| Desktop and computer use | VNC pane that streams a desktop to your browser; no computer-use API | None built in; you can run your own headless browser from a Dockerfile | 60fps desktop and Chromium, computer use and browser control |
| Keeping API keys out of the sandbox | Replit manages keys for some AI model providers; other keys are secrets in the app | Network shield can inject secrets into traffic, Enterprise only, limited access | Credentials proxy for model providers and any HTTPS API, on every plan |
| Idle and wake on request | Autoscale apps wake on the first request and go idle after 15 minutes | Standby after a 1 second idle cooldown by default; traffic wakes it in milliseconds | No wake on request; a stopped sandbox costs nothing and is started by API |
| Files over time | Workspace files and Agent checkpoints at milestones; published apps should not rely on their filesystem | Volumes, plus checkpoints of memory and volumes of a running microVM | Disk snapshots every minute and on stop; fork a running sandbox with its disk |
| Machine size | Reserved VMs at fixed sizes, such as 4 vCPU / 16 GB | 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 |
| Databases and storage | Postgres and App Storage built into each app | Volumes you attach to instances | No hosted databases; run your own inside a sandbox |
| Regions | North America, Europe, Asia, South America and Australia for published apps on Core and up | Dallas, Frankfurt, San Francisco, Singapore and Washington DC, more on request | EU only: Germany, Finland, France |
Every feature Battleships tracks (43)
| Feature | Replit | Unikraft Cloud | bochka |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | No | No | Yes |
| Nested virtualization | No | Yes | Yes |
| Root | Not published | Yes | Yes |
| Systemd | No | Not published | Yes |
| Desktop GUI | Yes | No | Yes |
| Browser | No | No | Yes |
| Computer-use API | No | No | Yes |
| SSH | Yes | No | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | No | Yes | Yes |
| Automatic snapshots | Yes | Yes | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | No | Yes | Yes |
| Memory fork | No | 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 | Not published | Not published | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | No | Yes | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | No | Yes | Yes |
| Preinstalled agents | Yes | No | Yes |
| Agent harness API | Yes | No | Yes |
| MCP server | Yes | No | No |
| GPU | No | Yes | No |
| Windows | No | No | No |
| Arm64 | Not published | Yes | No |
| Self-hosting | No | Yes | No |
| BYOC | No | Yes | No |
| Open source | No | No | No |
| Scoped API keys | Not published | Not published | Yes |
| Spend limits | Yes | Not published | Yes |
| Usage per sandbox (API) | Yes | No | Yes |
| Audit logs | Yes | Yes | No |
| SSO | Yes | No | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | No | Yes | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable measurement for either Replit or Unikraft Cloud: neither is in the StarSling hpc-sandbox-benchmarks run that measured bochka at 26.69 Node.js runs per second at 4 vCPU / 8 GB. Unikraft states cold starts under 10 ms, which is its own figure and measures 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. Replit and Unikraft Cloud have 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 | Replit, 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 | $122 · Pro $100 (annual) · with limits | $39 · Hobby | $20 · $20/mo |
| One agent that never stops 4 vCPU / 8 GB, 50 GB disk, running 24/7 all month | $122 · Pro $100 (annual) · with limits | $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 | $1,330 · Pro $1,000 (annual) · with limits | 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 | $403 · Pro $250 (annual) · 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 | $825 · Pro $1,000 (annual) · with limits | Can't run it | $2,000 · $2000/mo · with limits |
Replit: Replit plans (Core $20, Pro from $100) turn into monthly credits for Agent work and hosting, then usage goes pay-as-you-go. A Reserved VM has a fixed monthly price per size and bills whether busy or idle, while Autoscale bills only while it serves requests.
Unikraft Cloud: Unikraft Cloud charges a flat monthly fee for a pool of running capacity: free for 2 vCPU / 4 GiB, $39 for 8 vCPU / 8 GiB, $199 for 24 vCPU / 32 GiB, with sleeping instances not counted. 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 spent per second on running sandboxes. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Replit is marked as not a fit in every scenario because it is an app platform: each always-on machine is one published Reserved VM app billed all month, and it does not publish how many can run at once. Unikraft Cloud fits one agent on its Team pool, but 50 agents, 300 sandboxes for your users or 1,000 jobs at once are above every self-serve pool and need Enterprise. bochka fits all but the 1,000-job burst, where its $2,000 plan queues starts above 90 a minute.
| Scenario | Replit | Unikraft Cloud | bochka |
|---|---|---|---|
| One coding agent, workdays |
|
| None that bite |
| One agent that never stops |
|
| None that bite |
| 50 agents in parallel |
|
| None that bite |
| Sandboxes for your users |
|
| None that bite |
| 1,000 short jobs at once |
|
|
|
Which one should you use?
Use Replit when
you want Replit Agent to build a web app from a description and host it for you, with a database, sleeping when idle, and regions on five continents.
- An app built and hosted for you. Useful if you want a working app from a description: Replit Agent builds, tests and publishes it with Postgres and storage.
- A workspace people code in. Useful for people who build by hand or with Agent in the browser, with SSH into the workspace on paid plans.
- Regions on five continents. Useful if your users are spread out: published apps can run in North America, Europe, Asia, South America or Australia.
Use Unikraft Cloud when
you run many small services or headless browsers from your own Dockerfiles that sleep most of the time and must wake in milliseconds, or want GPUs or on-prem under Enterprise.
- Millisecond starts and scale-to-zero. Best for many small services that sleep most of the time and must answer the next request in milliseconds.
- Your Dockerfile becomes the VM. Useful if you already ship Dockerfiles: each one runs as its own microVM with no app builder in between.
- GPUs and your own hardware. Enterprise customers can get NVIDIA GPUs, arm64 hosts, dedicated hosts, on-prem or their own cloud.
Where bochka fits
If what you are really running is AI agents, neither Replit nor Unikraft Cloud was built for that job: Replit builds and hosts apps from a chat, and Unikraft runs small services that sleep. bochka gives each agent a full Linux VM that your code creates by API, with Docker, a desktop and coding agents you drive from outside.
A whole machine the agent can work in
Agents run docker compose, start databases and boot emulators. Replit sets up Nix packages and does not describe Docker, and Unikraft documents no Docker inside and keeps /dev/kvm for Enterprise. bochka has root, systemd, Docker and /dev/kvm on every plan.
Agents you drive from outside, keys kept out
Replit's MCP server drives only Replit Agent, and Unikraft ships no agents. bochka preinstalls Claude Code, Codex and more with a prompt, steer and events API, and its credentials proxy keeps keys for any HTTPS API outside, where Unikraft needs Enterprise.
Fleets of full-size machines, self-serve
Fifty 4 vCPU / 8 GB agents means 50 published Reserved VM apps on Replit, and is above every self-serve Unikraft pool. bochka runs 100 sandboxes at once from its first paid plan, with no session cap and free stops.
Use bochka when your own code needs to start machines for agents: full VMs with Docker and a desktop, coding agents you drive by API, keys kept outside, and fleets without a sales call. Compare it one to one: bochka vs Replit and bochka vs Unikraft Cloud.
Questions people ask
Is Replit cheaper than Unikraft Cloud?
For one agent machine, no. One coding agent that never stops comes to $122 a month on Replit as a Reserved VM and $39 on the Unikraft Team pool, against $26 on bochka. For 50 agents Replit comes to $1,330 but is not a fit, and Unikraft has no self-serve plan big enough.
Which is faster, Replit or Unikraft Cloud?
Neither has a comparable CPU measurement, so we cannot say. Unikraft starts faster: its microVMs cold boot in milliseconds by its own figure and wake on the next request, while Replit Autoscale wakes a published app on the first request.
Can Replit or Unikraft Cloud run Docker?
Replit sets up environments with Nix packages and does not describe running Docker. Unikraft uses your Dockerfile to build the VM image but does not document a container runtime inside a running instance. Every bochka sandbox is a full VM with Docker, systemd and /dev/kvm.
Can I SSH into Replit or Unikraft Cloud?
Replit lets you SSH into the workspace on paid plans. Unikraft Cloud does not have SSH yet; you run commands and move files through its sandbox plugin and CLI. You can SSH into every bochka sandbox.
Can I start many sandboxes from my own code?
Not on Replit: its MCP server creates and publishes apps through Replit Agent, with no API to start many machines. Unikraft lets you start instances from its CLI and SDK, but self-serve plans cap you at 24 running ones. bochka runs 100 to 2,000 sandboxes at once on paid plans.
Where do Replit and Unikraft Cloud run?
Replit hosts data mainly on Google Cloud in the United States and publishes apps on five continents on Core and up. Unikraft runs in Dallas, Frankfurt, San Francisco, Singapore and Washington DC. bochka runs only in the EU, in Germany, Finland and France.
Try bochka
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