Replit vs Upstash Box
Replit is a place where you describe an app, Replit Agent builds it, and Replit hosts it. Upstash Box is for your own code: it creates light containers for AI agents that pause when idle and wake on the next request.
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.
Upstash Box
Upstash Box is a cloud computer for AI agents from Upstash, the company known for serverless Redis, Vector and QStash.
Each box is a Docker container with its own filesystem, shell, git and an optional coding agent such as Claude Code, Codex or OpenCode, which you drive from TypeScript or Python SDKs. A box pauses when it sits idle, keeps its files, and you pay for the CPU it actually uses. Upstash built it to run its own Context7 service and opened it to everyone in March 2026.
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 | Upstash Box: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Upstash lets your code start many agent boxes while Replit drives one app at a time through Replit Agent, but neither runs Docker inside, which boat does on every machine. | 181st of 367, with limits $2,000 a month | 61st of 367, with limits $464 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Replit keeps an agent on as a Reserved VM that bills all month as one published app; Upstash uses a flat-price keep-alive box, and boat gives it a full VM with systemd. | 202nd of 366, with limits $2,033 a month | 103rd of 366, with limits $475 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 Upstash suits short code runs well, since an idle box costs no CPU and a paused box wakes when work arrives; Replit's Autoscale is a web host, not a code runner. | 228th of 345, with limits $146 a month | 10th cheapest of 345 $119 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 Upstash and boat both fit sandboxes for your users closely, while Replit does not publish how many deployments can run at once and each one is a published app. | 233rd of 361, with limits $825 a month | 2nd cheapest of 361 $222 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 | 258th of 360, with limits $4,226 a month | 352nd of 360, with limits $8,068 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 | 265th of 364, with limits $685 a month | 52nd cheapest of 364 $1,011 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 neither Replit's Nix environments nor Upstash's containers document, and which boat has on every machine. | 275th of 377, with limits $425 a month | 120th cheapest of 377 $1,520 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 good for coding by hand in the browser, an Upstash keep-alive box is a light always-on dev box, and boat's is a full VM with Docker. | 165th of 368, with limits $109 a month | 10th cheapest of 368 $20 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 and Upstash's browser is headless, so neither gives an agent a screen to click; boat streams a desktop at 60fps. | 190th of 369, with limits $619 a month | 73rd of 369, with limits $76 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 Upstash ships a managed headless Chromium with AI page actions and CDP, Replit has no browser for agents, and boat gives the agent a real desktop browser. | 229th of 367, with limits $317 a month | 49th of 367, with limits $38 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 | 234th of 346, with limits $217 a month | 37th cheapest of 346 $400 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 | 150th of 338, with limits $4,378 a month | 200th of 338, with limits $8,000 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 | 208th of 360, with limits $215 a month | 225th of 360, with limits $259 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 | Replit | Upstash Box | boat |
|---|---|---|---|
| Kind of product | AI app builder with browser workspaces and app hosting | Cloud computers for AI agents, driven from TypeScript or Python SDKs | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Not documented; the security page says strong logical separation between users | One Docker container per box on AWS | 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 | SDKs to create boxes, with 1,000 at once by default on Pay as You Go | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker inside | Not described; system packages come from Nix | Not documented; the box is itself a Docker container, and custom images are listed as coming soon | Yes, Docker, root and systemd run as on any Linux server |
| Nested virtualization | Not described in the docs | No; boxes are containers with no VM support documented | Yes, /dev/kvm for Android emulators and VMs |
| Files over time | Workspace files and Agent checkpoints at milestones; published apps should not rely on their filesystem | Pauses itself when idle and keeps its files; storage keeps billing while paused | Disk saved every minute and on stop; a stopped sandbox costs nothing |
| Wake on request | Autoscale starts on the first request and goes idle after 15 minutes | A request to a public URL resumes a paused box and waits for the app | No; a stopped sandbox is started by API |
| Coding agents | Replit Agent, which an MCP client can also drive (create, update, ask, publish) | Claude Code, Codex and OpenCode built in, with run and stream APIs, webhooks and scheduled prompts | Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API |
| Keeping keys out of the sandbox | Replit manages keys for OpenAI, Anthropic, Google and OpenRouter models; other keys are secrets in the app | Host proxy injects headers into outbound HTTPS on port 443; set when the box is created | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
| Desktop and browser | VNC pane that streams a native desktop to your browser; no computer-use API | Managed headless Chromium with AI page actions and CDP; no desktop | Linux desktop streamed at 60fps, Chromium and computer-use tools |
| Reaching the machine | Published apps on HTTPS domains and custom domains; SSH into the workspace on paid plans | HTTPS URL per port, public unless you add a token or basic auth; SSH through a gateway; no raw TCP | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP; SSH |
| Outbound rules | No provider-side allowlist documented | Allow all, deny all, or allow and deny by domain and CIDR, changeable on a running box | Open internet, no provider-side allowlist |
| Databases and storage | Postgres and App Storage built into each app | Not part of Box; Upstash sells Redis and Vector as separate products | 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 | US only (AWS us-east-1); more regions planned | EU only (Germany, Finland, France) |
Every feature Battleships tracks (43)
| Feature | Replit | Upstash Box | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | No | Yes |
| Docker inside | No | No | Yes |
| Nested virtualization | No | No | Yes |
| Root | Not published | Not published | Yes |
| Systemd | No | Not published | Yes |
| Desktop GUI | Yes | No | Yes |
| Browser | No | Yes | Yes |
| Computer-use API | No | No | Yes |
| SSH | Yes | Yes | Yes |
| Persistent disk | Yes | Yes | Yes |
| Pause/resume | No | Yes | Yes |
| Automatic snapshots | Yes | No | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | No | Yes | Yes |
| Memory fork | No | 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 | Not published | No | 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 | Yes | Yes |
| Agent harness API | Yes | Yes | Yes |
| MCP server | Yes | Yes | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | Not published | Yes | No |
| Self-hosting | No | No | No |
| BYOC | No | No | 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 | Yes | Yes |
| Audit logs | Yes | Not published | No |
| SSO | Yes | No | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | No | No | No |
| EU data residency | Yes | No | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable measurement for Replit or Upstash Box: neither is in StarSling's public hpc-sandbox-benchmarks CPU test. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB in that benchmark, on dedicated AMD Ryzen 9 9950X hosts, so we cannot say which of the three is fastest.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Replit and Upstash Box 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 | Upstash Box, a month | boat, 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 | $21 · Pay as You Go | $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 | $21 · Pay as You Go | $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 | $900 · Pay as You Go · 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 | $403 · Pro $250 (annual) · with limits | $306 · Pay as You Go | $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 | $1,822 · Pay as You Go | $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 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 bills price agents as Reserved VMs and leave out Agent usage.
Upstash Box: A standard box is billed for the CPU it actually uses, at $0.10, $0.20 or $0.40 per active CPU hour for Small, Medium and Large, plus $0.10 per GB-month of storage, and RAM is free. A keep-alive box costs a flat $8, $16 or $32 a month, busy or not.
Upstash Box: Plans start at $20 a month, and the whole fee is usage credit spent per second while a sandbox 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, so 300 or 1,000 machines are not confirmed. Upstash fits four of the five scenarios but not 50 agents in parallel, because it has no Docker inside a box, and its egress price is not published. boat fits all but the 1,000-job burst, where it queues starts above 90 a minute and allows 2,400 starts a day on the $2,000 plan.
| Scenario | Replit | Upstash Box | boat |
|---|---|---|---|
| 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 Postgres, sleeping when idle, or regions outside the US and Europe.
- 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 a domain.
- Databases next to the app. Useful for full web apps: each Replit app gets Postgres and App Storage without setting them up yourself.
- Regions on five continents. Useful if your users are spread out: Replit publishes apps in North America, Europe, Asia, South America and Australia.
Use Upstash Box when
your code starts many light agent boxes that mostly wait, wake on an incoming request, follow a strict outbound allowlist, or must run in the US.
- Boxes your code starts by the thousand. Useful for agent platforms: your code starts boxes from an SDK, with 1,000 at once by default.
- Idle costs no CPU. Good for agents that wait a lot: an idle box costs no CPU, and a request to its URL wakes it.
- Outbound network rules. Useful when an agent may only reach a short list of domains or IP ranges.
Where boat fits
If what you are really running is agents, Replit is the wrong shape: it builds and hosts apps, one published app at a time. Upstash Box fits agents but gives them a light container. Look at boat when your agents need a whole Linux machine that your code starts, forks and stops, with Docker, a desktop and a big disk.
Docker, systemd and /dev/kvm
An agent that runs docker compose, starts a database as a service or boots an Android emulator gets stuck on both. Replit's Nix setup and Upstash's containers do not document Docker inside, so the 50-agent scenario fits neither.
A desktop the agent can see
Computer-use agents need a screen to click. Replit's VNC pane is for a person in the workspace, and Upstash's Chromium is headless, so desktop apps and native dialogs are out of reach. boat streams a Linux desktop at 60fps.
Machines your code owns, with room to work
On Replit each always-on machine is a published Reserved VM app. Upstash disks stop at 20 GB and boxes at 8 vCPU / 16 GB. boat sandboxes have 50 GB by default, save the disk every minute, and fork while running.
Use boat when your agents need a real machine: Docker, emulators, a 60fps desktop, a big disk saved every minute, and coding agents you drive from outside. Compare it one to one: boat vs Replit and boat vs Upstash Box.
Questions people ask
Is Replit cheaper than Upstash Box?
For agent machines, Upstash costs less in four of the five scenarios we priced: one coding agent on workdays is $21 a month on Upstash against $122 on Replit, and sandboxes for your users are $306 against $403. Replit is lower for 1,000 short jobs at once, $825 against $1,822, but it is not confirmed to run that many. boat comes to $20 and $200 in those first two.
Is Replit a sandbox for AI agents like Upstash Box?
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. Upstash Box and boat are built for code that creates a machine per agent or per user.
Which is faster, Replit or Upstash Box?
We cannot say: neither is in the public CPU benchmark we use. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB in it.
Can Replit or Upstash Box run Docker?
Replit's docs set up environments with Nix packages and do not describe Docker inside. An Upstash box is itself a Docker container, its docs do not offer Docker inside it, and custom images are listed as coming soon. Every boat sandbox is a full VM with root, systemd, Docker and /dev/kvm.
Can I drive Claude Code or Codex on them from my own code?
On Upstash Box, yes: Claude Code, Codex and OpenCode are built in, with run and stream APIs and webhooks. Replit's MCP server drives Replit Agent only. boat preinstalls Claude Code, Codex, OpenCode and more, with a prompt, steer and events API.
Where do Replit and Upstash Box run?
Replit hosts data mainly on Google Cloud in the United States, and on Core and up you can publish apps in North America, Europe, Asia, South America or Australia. Upstash Box runs only in AWS us-east-1. boat runs in the EU, in Germany, Finland and France.
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