Blaxel vs Replit
Blaxel gives your code Firecracker microVM sandboxes that sleep in seconds and wake in under 25 ms. Replit is a place where Replit Agent builds an app from a chat and Replit hosts it, so the two only overlap at the edges.
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
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.
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 | Replit: 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 that starts many sandboxes from code, while Replit's outside entry point is an MCP server that drives Replit Agent one app at a time; bochka adds /dev/kvm and a real disk. | 10th cheapest of 367 $2,373 a month | 181st of 367, with limits $2,000 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Blaxel's sleep and wake on request suits mostly idle assistants, while on Replit an always-on assistant means a Reserved VM that bills all month. | 12th cheapest of 366 $2,832 a month | 202nd of 366, with limits $2,033 a month | 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 Blaxel is built for short runs that sleep right away and resume in milliseconds, and Replit's Autoscale is a web host, not a code runner. | 14th cheapest of 345 $144 a month | 228th of 345, with limits $146 a month | 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 public tiers stop at 200 sandboxes at once and Replit does not publish a limit, while bochka fits 300 users at once on a self-serve plan. | 101st of 361, with limits $926 a month | 233rd of 361, with limits $825 a month | 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 | 258th of 360, with limits $4,226 a month | 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 | 265th of 364, with limits $685 a month | 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, which Blaxel offers through a Docker-in-sandbox image and Replit's Nix-based environments do not document. | 57th cheapest of 377 $431 a month | 275th of 377, with limits $425 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB A Replit workspace is a good place to code by hand with SSH on paid plans, while Blaxel has no native SSH and bochka is a plain machine you SSH into and leave on. | 265th of 368, with limits $114 a month | 165th of 368, with limits $109 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 an agent can control, Replit's VNC pane only shows a desktop to a person, and bochka streams a 60fps desktop. | 14th cheapest of 369 $634 a month | 190th of 369, with limits $619 a month | 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 | 16th cheapest of 367 $317 a month | 229th of 367, with limits $317 a month | 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 | 234th of 346, with limits $217 a month | 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 | 150th of 338, with limits $4,378 a month | 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 fits with domain-level egress rules on the provider side, and bochka gives root with raw TCP and nftables. | 3rd cheapest of 360 $217 a month | 208th of 360, with limits $215 a month | 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 | Replit | bochka |
|---|---|---|---|
| Kind of product | Sandboxes, batch jobs, MCP hosting and a model gateway for AI agents | AI app builder with browser workspaces and app hosting | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Firecracker microVM per sandbox, own kernel | Not documented; the security page says strong logical separation between users | Full VM with its own kernel, on dedicated AMD Ryzen 9 9950X hosts |
| Creating machines from code | API and SDK to start many sandboxes | MCP server tools to create, update and publish apps; no API to start many machines | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker and nested virtualization | Docker with a Docker-in-sandbox image; no /dev/kvm | System packages come from Nix; the docs do not describe Docker, systemd or /dev/kvm | Docker, root, systemd and /dev/kvm on every machine |
| Files over time | Files live in memory (about half the RAM); one block volume can be attached at creation | Workspace files and Agent checkpoints; published apps should not rely on their filesystem | A real disk, snapshotted every minute and on stop |
| Sleep and wake | Standby a few seconds after the last connection, wakes in under 25 ms with memory and processes | Autoscale apps wake on the first request and go idle after 15 minutes | Stop keeps the disk and costs nothing; resume boots the VM again |
| Fork | Fork with memory and running processes (private preview) | No fork of a running machine; Agent checkpoints at milestones | Fork a running sandbox (disk) |
| Coding agents | Claude Code image you drive from its terminal or your own harness | Replit Agent, which you can also drive from an MCP client | Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API |
| Keeping keys out of the sandbox | Proxy fills secrets into outbound HTTPS requests (public preview) | Managed keys for AI models only; other keys are secrets in the app | AI credentials proxy for model providers and any HTTPS API you register |
| Desktop and computer use | Desktop and browser with computer use and browser control | VNC pane that streams a desktop to your browser; no computer-use API | 60fps desktop and Chromium, computer use and browser control, embeddable stream |
| Reaching the machine | Preview URL per port, public or token-protected; no native SSH, raw TCP or public IP | Published apps on HTTPS and custom domains; SSH into the workspace on paid plans | HTTPS URLs for up to 50 ports, token-protected; raw TCP; own IPv6 or IPv4; SSH |
| Outbound rules | Domain allow and deny lists, method and path rules, static egress IPs | Open internet | Open internet; filter inside the VM with nftables |
| Databases and app hosting | Not among its products (sandboxes, batch jobs, MCP hosting, model gateway) | Postgres and App Storage built into each published app | No hosted databases; run your own inside a sandbox |
| Regions | Oregon, North Virginia, London, Frankfurt | Data mainly in the US; apps published in North America, Europe, Asia, South America or Australia | EU only: Germany, Finland, France |
Every feature Battleships tracks (43)
| Feature | Blaxel | Replit | bochka |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | Yes | No | Yes |
| Nested virtualization | No | No | Yes |
| Root | Yes | Not published | Yes |
| Systemd | No | No | Yes |
| Desktop GUI | Yes | Yes | Yes |
| Browser | Yes | No | Yes |
| Computer-use API | Yes | No | Yes |
| SSH | No | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | Yes | No | Yes |
| Automatic snapshots | Yes | Yes | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | Yes | No | Yes |
| Memory fork | Yes | No | 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 | No | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | Yes | No | Yes |
| Preinstalled agents | Yes | Yes | Yes |
| Agent harness API | No | Yes | Yes |
| MCP server | Yes | Yes | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | No | Not published | No |
| Self-hosting | No | No | No |
| BYOC | Yes | No | No |
| Open source | No | No | No |
| Scoped API keys | Yes | Not published | Yes |
| Spend limits | No | Yes | Yes |
| Usage per sandbox (API) | Yes | Yes | Yes |
| Audit logs | Not published | Yes | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | Yes | No | No |
| EU data residency | Yes | Yes | Yes |
| Zero data retention | Yes | Not published | Yes |
Performance
In StarSling's Node.js build-and-test benchmark at 4 vCPU and 8 GB, run on September 29, 2026, bochka did 26.69 runs per second and Blaxel 19.48, so bochka got about 1.4 times the work done in the same time. Replit is not in that benchmark, so there is no comparable measurement for it.
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). Replit 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 | Replit, 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 | $122 · Pro $100 (annual) · with limits | $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 | $122 · Pro $100 (annual) · with limits | $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 | $1,330 · Pro $1,000 (annual) · with limits | $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 | $403 · Pro $250 (annual) · with limits | $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 | $825 · Pro $1,000 (annual) · with limits | $2,000 · $2000/mo · with limits |
Blaxel: Blaxel charges for allocated RAM per second while a sandbox is active, with CPU included (8 GB comes with 4 cores). In standby you pay only snapshot storage, and volumes are billed on their full size.
Replit: Replit plans (Core $20, Pro from $100) turn into monthly credits for Agent work and hosting, then usage goes on to pay-as-you-go. A Reserved VM has a fixed monthly price per size, such as $130 for 4 vCPU / 16 GB, and bills whether busy or idle; our scenarios price agents as Reserved VMs and leave out Agent usage.
Replit: Your plan payment (from $20 a month) is all usage credit, billed per second while a machine runs. 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: one Reserved VM is one published app that runs all month, and it does not publish how many can run at once. Blaxel fits the agent scenarios, but its self-serve tiers allow 10, 50 or 200 sandboxes at once, standby ones included, so 300 users or 1,000 jobs at once need a sales tier. On bochka, the 1,000-job burst is queued above 90 starts a minute and needs more starts per day than the $2,000 plan allows.
| Scenario | Blaxel | Replit | 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
your code starts many sandboxes that sit idle most of the time and must wake in milliseconds with their memory, or must run in the US.
- Sandboxes your code starts. Useful if your product starts a sandbox per task or per user from code, which Replit has no API for.
- Sleeps in seconds, wakes in milliseconds. Useful if your sandboxes sit idle most of the time: one sleeps after the last connection and wakes in under 25 ms.
- Network rules on the provider side. Blaxel can limit a sandbox to chosen domains, down to methods and paths, and give it static egress IPs.
Use Replit when
you want Replit Agent to build a web app from a description and host it for you, with databases, sleeping when idle, or 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.
- Databases and storage next to the app. Each published app can use built-in Postgres and App Storage, with no database to run yourself.
- Regions on five continents. Useful if your users are far apart: apps publish in North America, Europe, Asia, South America and Australia.
Where bochka fits
If what you are really running is agents that do long work, like builds, tests, Docker and emulators, look at bochka. Blaxel is shaped for sandboxes that sleep most of the time, and Replit is shaped for one app built by its own agent. bochka gives each agent a whole Linux machine with a real disk, a faster CPU and agents you drive from outside.
A whole Linux machine
Without /dev/kvm an Android emulator or a VM does not start at all, and neither Blaxel's Firecracker guests nor Replit offer it. Replit does not document Docker or systemd either, so those jobs have to fit Nix packages or be dropped.
A disk that stays
Blaxel keeps files in memory, about half the RAM, so a big repo can fill it unless you attach a volume at creation. Replit's published apps should not rely on their filesystem. bochka snapshots a real disk every minute, and a stopped sandbox costs nothing.
Agents driven from outside
On Blaxel you build the agent harness yourself around a Claude Code image, and Replit's MCP server drives only Replit Agent with no event stream. bochka lets your app prompt, steer and stream events from Claude Code, Codex and others.
Use bochka when your agents do real work for hours: builds, tests, Docker and emulators on a whole Linux machine with a real disk, a faster CPU and agents you drive from outside. Compare it one to one: bochka vs Blaxel and bochka vs Replit.
Questions people ask
Is Blaxel cheaper than Replit?
For one coding agent on workdays Blaxel comes to $33 against $122 on Replit, because a Replit Reserved VM bills all month. For one agent that never stops they are close, $120 on Blaxel against $122 on Replit, and for 50 agents in parallel Replit is lower at $1,330 against $1,489, though Replit is not a fit there. bochka comes to $20, $26 and $317 for those three.
Which is faster, Blaxel or Replit?
We cannot say, because Replit is not in the benchmark. In the same Node.js build-and-test run at 4 vCPU and 8 GB, Blaxel did 19.48 runs per second and bochka 26.69.
Can I run Docker on Blaxel or Replit?
On Blaxel, yes, with its Docker-in-sandbox image. Replit's docs set up environments with Nix packages and do not describe running Docker. Every bochka sandbox has root, systemd, Docker and /dev/kvm.
Is Replit a sandbox for AI agents like Blaxel?
Not in the usual sense. Replit is an app builder where Replit Agent writes and publishes apps, and there is no API to start many machines. Blaxel and bochka are both sandboxes your own code creates by API.
Can I SSH into Blaxel or Replit?
Replit lets you SSH into a workspace on paid plans. Blaxel has no native SSH and gives you a terminal through the bl connect command. bochka gives real SSH, root and systemd.
Where do Blaxel and Replit run?
Blaxel runs in Oregon, North Virginia, London and Frankfurt. Replit hosts data mainly on Google Cloud in the United States and publishes apps in North America, Europe, Asia, South America or Australia on Core and up. bochka runs only in the EU, in Germany, Finland and France.
Try bochka
Install the CLI, then run bochka new.
Product preview