Replit vs Agent 37
Replit is an AI app builder: you describe an app, Replit Agent writes it, and Replit hosts it. Agent 37 is an API that gives each of your users their own agent sandbox, which can sleep when idle and wake on the next message.
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.
Agent 37
Agent 37 hosts AI agents, one isolated, always-on sandbox per user, behind one API.
You create an instance from a template (Hermes, OpenClaw, Claude Code, Codex, OpenCode, Pi, Grok or your own Docker image) and talk to it through a chat API, files, exec, SSH and HTTPS URLs. The default instance is a container enforced by gVisor; a VM type gives a full Linux machine with its own kernel for Docker, Kubernetes and Android emulators. It is built for companies that give each of their customers an agent.
- Where it runs
- Dedicated servers in the United States
- Instance types
- Default (shared), Performance (dedicated cores), VM
- Compliance
- SOC 2 Type I, Type II in progress
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 | Agent 37: price rank | boat: 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, which Agent 37 and boat do by API, while Replit's MCP server drives Replit Agent one app at a time. | 181st of 367, with limits $2,000 a month | 2nd cheapest of 367 $551 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB This is what Agent 37 is built for: one always-on assistant per user that sleeps when idle and wakes on the next message, while on Replit each one is a Reserved VM app billed all month. | 202nd of 366, with limits $2,033 a month | Cheapest of 366 $279 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 Agent 37's small default sandboxes suit short code runs; Replit's Autoscale is a web host, not a code runner, and boat's start limits make big bursts a poor fit. | 228th of 345, with limits $146 a month | Cheapest of 345 $22 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 Agent 37 holds up to 200 instances on its top self-serve tier, counting sleeping ones, and Replit does not publish how many deployments can run at once; boat plans go up to 2,000. | 233rd of 361, with limits $825 a month | 30th of 361, with limits $79 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 | 6th of 360, with limits $363 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 | 90th of 364, with limits $58 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 boat has on every machine, Agent 37 has only on its VM type, and Replit does not document. | 275th of 377, with limits $425 a month | 2nd cheapest of 377 $84 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Replit is a good place to code by hand in the browser, while Agent 37 and boat keep a full machine and its disk around the clock. | 165th of 368, with limits $109 a month | 3rd cheapest of 368 $12 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 Agent 37 adds a noVNC desktop through a template, boat streams a 60fps desktop out of the box, and Replit's VNC pane is for a person, with no computer-use API. | 190th of 369, with limits $619 a month | Cheapest of 369 $53 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 | 229th of 367, with limits $317 a month | 48th of 367, with limits $29 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 | Cheapest of 346 $32 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 | 36th of 338, with limits $648 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 boat can fork a running VM to try many paths at once; Agent 37 has no fork, and Replit has no API to start many machines. | 208th of 360, with limits $215 a month | Cheapest of 360 $43 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 | Agent 37 | boat |
|---|---|---|---|
| Kind of product | AI app builder with browser workspaces and app hosting | Agent sandboxes by API, one per user, with a chat API per instance | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Not documented; the security page says strong logical separation between users | gVisor by default; full VM as an opt-in instance type | Every sandbox is a full VM with its own kernel |
| Creating machines from code | MCP server tools to create, update and publish apps; no API to start many machines | API to create instances from templates, with files, exec, SSH and HTTPS URLs | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker inside | System packages come from Nix; the docs do not describe Docker | Only on the VM type, at 2.5x the default compute rate | Docker, root and systemd in every sandbox |
| Nested virtualization | Not described in the docs | /dev/kvm on the VM type, with a ready Android template | /dev/kvm in every sandbox, Android emulator works |
| Sleep when idle | Autoscale apps wake on the first request and go idle after 15 minutes | Opt-in auto-sleep (default 15 minutes) that keeps memory and wakes on the next request | No idle timer; a time limit you set, or no limit; a stopped sandbox costs nothing |
| Fork and snapshots | Agent checkpoints at milestones in the workspace | No fork; daily backups plus one on-demand backup, restored in place only | Fork a running sandbox; snapshots every minute; named snapshots as templates |
| Custom images | Nix packages in the workspace | Your own linux/amd64 Docker image as a template | Templates from named snapshots, no Dockerfile builds |
| Coding agents | Replit Agent, which you can also drive from an MCP client | Hermes, OpenClaw, Claude Code, Codex, Grok, OpenCode, Pi, with a chat API | Claude Code, Codex, OpenCode, pi and more, with a prompt, steer and events API |
| Keys kept out of the sandbox | Managed keys for OpenAI, Anthropic, Google and OpenRouter models; other keys are app secrets | Managed LLM, search and Composio through a per-instance token; your own keys go in as env vars | Proxy for model providers and any HTTPS API you register, with credential switching when credits run out |
| Desktop and computer use | VNC pane that streams a desktop to a person; no computer-use API | noVNC desktop through a template build or the Ubuntu VM template | 60fps desktop and Chromium in every sandbox, computer use, embeddable stream |
| Hosting and databases | Published apps on HTTPS domains, with Postgres and App Storage built in | HTTPS URL per port, signed URLs, custom domains; no public IP | HTTPS URLs for up to 50 ports, raw TCP, dedicated IPv6 or IPv4; no hosted databases |
| Regions | North America, Europe, Asia, South America and Australia for published apps on Core and up | United States | EU only: Germany, Finland, France, with EU data residency |
Every feature Battleships tracks (43)
| Feature | Replit | Agent 37 | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | No | Yes |
| Docker inside | No | No | Yes |
| Nested virtualization | No | No | Yes |
| Root | Not published | Yes | Yes |
| Systemd | No | Not published | Yes |
| Desktop GUI | Yes | Yes | Yes |
| Browser | No | Yes | Yes |
| Computer-use API | No | Yes | Yes |
| SSH | Yes | Yes | 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 | 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 | Not published | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | No | No | No |
| Secret proxy | Yes | Yes | Yes |
| Secret proxy for any API | No | No | Yes |
| Preinstalled agents | Yes | Yes | Yes |
| Agent harness API | Yes | Yes | Yes |
| MCP server | Yes | No | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | Not published | No | 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 | Yes | 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 Agent 37: neither is in StarSling's public hpc-sandbox-benchmarks. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB there. Agent 37 says its default instances share host resources and sells a Performance type on dedicated cores.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Replit and Agent 37 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 | Agent 37, 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 | $6 · Wallet (any top-up) | $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 | $12 · Wallet (any top-up) | $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 | $329 · Wallet ($100 lifetime top-ups) | $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 | $33 · Wallet ($250 lifetime top-ups) · 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 | $825 · Pro $1,000 (annual) · with limits | $73 · Wallet ($250 lifetime top-ups) · with limits | $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, the only kind that stays on, has a fixed monthly price per size and bills whether busy or idle.
Agent 37: Agent 37 uses a prepaid wallet with no plan fee, metered per minute: $0.80 per vCPU and $0.70 per GB of RAM per month while running, plus $0.09 per GB of disk per month even while asleep. VM compute costs 2.5x and Performance compute 4x the default rate.
Agent 37: A monthly plan from $20, and all of it 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: one Reserved VM is one published app that runs all month, and it does not publish how many deployments can run at once. Agent 37 caps instances at 10 after a first top-up, 50 at $100 of total top-ups and 200 at $250, counting sleeping and stopped ones, so 300 sandboxes for your users or 1,000 jobs at once do not fit. Its 50-agent scenario needs Docker, so it is priced on the VM type. On boat, 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 | Replit | Agent 37 | 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 databases, 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.
- Web hosting that costs nothing when idle. Useful for web apps with uneven traffic: Autoscale wakes on the first request and costs nothing while idle.
- Regions on five continents. Useful if your users are spread out: Replit publishes apps in North America, Europe, Asia, South America and Australia.
Use Agent 37 when
you host one mostly idle assistant per customer in the US that should sleep with its memory kept and wake on the next message.
- One agent sandbox per user, by API. Useful if you give each customer an agent: your code creates instances from templates and talks to them through a chat API.
- Sleeps when idle and keeps its memory. Useful for assistants idle most of the day: an instance sleeps, keeps its memory and wakes on the next message.
- Bring a Dockerfile, pick dedicated cores. Agent 37 builds templates from your own Docker image, and sells a Performance type on dedicated cores.
Where boat fits
If your own code needs to start machines for agents that do real work, look at boat. Every sandbox is a full VM with Docker, systemd and a desktop, you can fork one while it runs, and keys stay outside for any API. Replit is built for people who want an app, and Agent 37 is built around light sandboxes that sleep.
A full VM by default
Agents run docker compose, start services and boot emulators. Replit's docs do not describe Docker or systemd, and on Agent 37 Docker needs the VM type at 2.5x the compute rate, still with no init system.
Fork a machine while it runs
Without a fork, you cannot split one half-done task into several tries at once. Agent 37 backups restore only onto the same instance, and Replit has no API to start many machines.
Keys stay outside, for any API
On Replit, keys other than its managed AI models are app secrets, and on Agent 37 your own keys are env vars inside the instance. Code the agent runs can read them; boat's proxy keeps them outside for any HTTPS API.
Use boat when your agents do real work for hours: Docker, systemd and emulators on a full VM, forks of running machines, a 60fps desktop and keys kept outside for any API. Compare it one to one: boat vs Replit and boat vs Agent 37.
Questions people ask
Is Replit cheaper than Agent 37?
No, not for agent machines. One agent that never stops comes to $122 a month on Replit and $12 on Agent 37 (boat: $26), and 50 agents in parallel come to $1,330 on Replit against $329 on Agent 37 (boat: $317). Replit prices an always-on agent as a Reserved VM that bills all month.
Is Replit an agent sandbox like Agent 37?
No. Replit is an app builder where Replit Agent writes and publishes apps, and its machines are workspaces and published deployments. Agent 37 gives your code one sandbox per user by API, and so does boat.
Which is faster, Replit or Agent 37?
We cannot say: neither has a result on StarSling's public benchmark. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB there. Agent 37 sells a Performance type on dedicated cores for steady speed.
Can Replit or Agent 37 run Docker?
Replit's docs set up environments with Nix packages and do not describe Docker. Agent 37 runs Docker only on its VM type, which bills compute at 2.5x; the default gVisor type cannot run a Docker daemon. Every boat sandbox runs Docker.
Where do Replit and Agent 37 run?
Replit hosts data mainly on Google Cloud in the United States, and on Core and up publishes apps in North America, Europe, Asia, South America or Australia. Agent 37 runs on dedicated servers in the United States. boat runs only in the EU, in Germany, Finland and France.
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