Replit vs Together Code Sandbox
Replit is an AI app builder: you describe an app, Replit Agent writes it, and Replit hosts it. Together Code Sandbox runs code in VMs your program starts through an SDK, but Together has to turn it on for your organization first.
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.
Together Code Sandbox
Together AI is a cloud for running and training AI models, and Code Sandbox is its product for running code in isolated VMs.
You build a snapshot from a Docker image or Dockerfile on Together's builder, then start sandboxes from it and run commands and file operations through the together-sandbox SDK or CLI. When a sandbox ends you can save its disk, and its memory too, as a new snapshot to start more sandboxes from. It is aimed at model-generated code, agent tool calls and reinforcement learning rollouts, and it must be enabled for your organization by Together. Together also sells Code Interpreter, a separate API that runs Python code in short sessions.
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 | Together Code Sandbox: 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; Together's SDK can do that once enabled, while Replit's outside entry point is an MCP server that drives Replit Agent one app at a time, and boat ships the agents with Docker on every machine. | 181st of 367, with limits $2,000 a month | 65th of 367, with limits $528 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB An always-on assistant on Replit is a Reserved VM that bills all month, Together has no idle detection or wake on request, and on boat a sandbox can run for weeks and stops billing when you stop it. | 202nd of 366, with limits $2,033 a month | 152nd of 366, with limits $1,095 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 For short code runs, Replit's Autoscale bills only while it serves requests and Together's Code Interpreter runs Python in 60-minute sessions, so both fit small bursts better than a full machine. | 228th of 345, with limits $146 a month | 326th of 345, with limits $2,190 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 Replit does not publish how many deployments can run at once, and every Together port is public with preview URLs still coming soon, while boat gives each user token-protected HTTPS URLs. | 233rd of 361, with limits $825 a month | 234th of 361, with limits $900 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 Together can save a sandbox with its memory and start many copies from it, which suits rollouts that branch from one warm state; Replit has nothing like that. | 258th of 360, with limits $4,226 a month | 315th of 360, with limits $21,900 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 | 258th of 364, with limits $450 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 and neither Replit's Nix-based environments nor Together's new SDK document. | 275th of 377, with limits $425 a month | 251st of 377, with limits $180 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, but it has no Docker or systemd; Together sandboxes have no SSH; boat gives you SSH, Docker and systemd. | 165th of 368, with limits $109 a month | 210th of 368, with limits $22 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 Computer-use agents need a desktop an agent can click; Replit's VNC pane shows a desktop to a person, Together has none, and boat streams one at 60fps with computer-use tools. | 190th of 369, with limits $619 a month | 184th of 369, with limits $600 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 | 301st of 367, with limits $900 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 | 219th of 346, with limits $180 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 | 124th of 338, with limits $3,600 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 | 167th of 360, with limits $150 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 | Together Code Sandbox | boat |
|---|---|---|---|
| Kind of product | AI app builder with browser workspaces and app hosting | VM sandboxes started from Docker-image snapshots through an SDK and CLI, plus a Python Code Interpreter API | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Not documented; the security page says strong logical separation between users | A VM per sandbox on Together's infrastructure | Full VM with its own kernel on dedicated AMD Ryzen 9 9950X hosts |
| Getting started | Sign up, free Starter plan | The SDK and CLI must be enabled for your organization by Together; Code Interpreter is self-serve with prepaid credits | Sign up and start a sandbox from the API, CLI or dashboard |
| Creating machines from code | MCP server tools to create, update and publish apps; no API to start many machines | SDK and CLI to start sandboxes, run commands and move files | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker, root and systemd | System packages come from Nix; Docker and systemd not described | Commands run as user 1000 by default, root on request; Docker inside not documented | Docker, systemd and root on every machine |
| Nested virtualization | Not documented | Not documented | Yes, /dev/kvm for Android emulators and VMs |
| Shell access | SSH into the workspace on paid plans | Commands, interactive shells and files through the SDK and CLI; no SSH | SSH, plus exec and files over the API |
| Saving state | Workspace files and Agent checkpoints; published apps should not rely on their filesystem | End a sandbox with a snapshot of its disk, or disk and memory, and start new ones with processes running | Disk saved every minute and on stop; a stopped sandbox costs nothing; resume boots the machine again |
| Fork | No fork of a running machine | No live fork: the parent stops, then you start many sandboxes from its snapshot | Fork a running sandbox; the original keeps running |
| Idle and wake | Autoscale starts on the first request and goes idle after 15 minutes, costing nothing while idle | Time to live counts from creation; no idle detection and no wake on request | Runs until you stop it or its time to live ends; started again by API |
| Reaching the machine | Published apps on HTTPS domains, custom domains and private deployments | All ports public; preview URLs coming soon; an experimental inbound allowlist | HTTPS URLs for up to 50 ports, token-protected by default; raw TCP; dedicated IPv6 or IPv4 |
| Desktop and computer use | VNC pane that streams a desktop to your browser; no computer-use API | None; headless command and file access only | Linux desktop streamed at 60fps, Chromium and computer-use tools |
| Coding agents | Replit Agent, which you can also drive from an MCP client | Run your own agent through execs; a Harbor guide for agent evals | Claude Code, Codex, OpenCode and more preinstalled, with a prompt, steer and events API |
| Keeping keys out of the sandbox | Replit manages keys for some AI models, billed to credits; other keys are secrets in the app | No credentials proxy documented | Credentials proxy for model providers and any HTTPS API; switch a credential to another account when credits run out |
Every feature Battleships tracks (43)
| Feature | Replit | Together Code Sandbox | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | No | Not published | Yes |
| Nested virtualization | No | No | 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 | No | Yes |
| Fork/clone | Yes | Yes | Yes |
| Live fork (no pause) | No | No | Yes |
| Memory fork | No | Yes | No |
| Custom image (Docker or snapshot) | Yes | Yes | Yes |
| ≥24 h sessions | Yes | Yes | Yes |
| Idle auto-stop | Yes | No | No |
| Wake on request | Yes | No | No |
| HTTPS preview URLs | Yes | Yes | Yes |
| Raw TCP inbound | Not published | No | Yes |
| Public IPv4 | No | No | No |
| Egress allowlist | No | No | No |
| Secret proxy | Yes | No | Yes |
| Secret proxy for any API | No | No | Yes |
| Preinstalled agents | Yes | No | Yes |
| Agent harness API | Yes | No | Yes |
| MCP server | Yes | Yes | 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 | Yes | No |
| SOC 2 | Yes | Yes | No |
| HIPAA | No | No | No |
| EU data residency | Yes | Not published | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable CPU measurement for Replit or Together Code Sandbox: neither is in StarSling's hpc-sandbox-benchmarks. 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 faster.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Replit and Together Code Sandbox 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 | Together Code Sandbox, 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 | $5 · Together pay-as-you-go (prepaid credits; Code Interpreter only) · with limits | $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 | $22 · Together pay-as-you-go (prepaid credits; Code Interpreter only) · 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 | $1,330 · Pro $1,000 (annual) · with limits | $264 · Together pay-as-you-go (prepaid credits; Code Interpreter only) · 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 | $900 · Together pay-as-you-go (prepaid credits; Code Interpreter only) · 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 | $6,000 · Together pay-as-you-go (prepaid credits; Code Interpreter only) · 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. Our scenarios price agents as Reserved VMs, which run and bill all month at a fixed price per size, and leave out Agent usage.
Together Code Sandbox: Together lists Code Sandbox at $0.0446 per vCPU-hour and $0.0149 per GiB-hour, but the VMs must be enabled for your organization, so the table prices Code Interpreter instead: $0.03 per 60-minute session from prepaid credits.
Together Code Sandbox: Plans start at $20 a month, and the whole fee becomes usage credit spent per second while sandboxes run. A stopped sandbox costs nothing and keeps its disk.
Limits in those scenarios
Neither fits any scenario as is. Replit is an app platform: each always-on machine is a published Reserved VM that bills all month, so one workday agent costs $122 a month, and how many deployments can run at once is not published. The Together column is Code Interpreter, whose sessions end after 60 minutes, keep no disk and run only Python, which is why it looks low at $264 a month for 50 agents but reaches $6,000 for 1,000 short jobs at once. On boat the limit that bites is starts: that 1,000-job burst needs more starts per hour and per day than the $2,000 plan allows, so starts are queued.
| Scenario | Replit | Together Code Sandbox | 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, 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, with Postgres and storage.
- 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 Together Code Sandbox when
you already run models on Together, can get the SDK enabled, and want light sandboxes you can save with their memory and branch from, or a simple Python runner billed per session.
- Memory snapshots to branch from. Useful for rollouts and test variants: save a sandbox with its memory and start many copies with processes still running.
- Sandboxes next to your models. Handy if you already run inference or fine-tuning on Together: sandboxes and models share one account and API key.
- Very small machines and a Python runner. Good for many light jobs: sandboxes start at a tenth of a core, and a Python interpreter API bills per session.
Where boat fits
If what you are really running is agents, look at boat. Replit builds and hosts apps for people, and Together's VM sandboxes need Together to enable them and stop at running commands. boat gives each agent a whole machine you can start today, with Docker, a desktop, hosting and the coding agents already inside.
A whole machine with Docker and KVM
Agents run docker compose, start services and boot emulators. Replit sets up Nix packages and Together runs commands as a normal user, and neither documents Docker inside or /dev/kvm, so you bake every tool into an image or drop the job.
Agents driven from outside, keys kept out
Replit's MCP server drives only Replit Agent, and on Together you wire your own agent through execs. Keys you pass in sit inside a machine the agent controls; boat's credentials proxy keeps them outside for any HTTPS API.
Private hosting and a desktop
On Together every port is public until you set an experimental policy, and there is no desktop. Replit's VNC pane is for a person to watch. boat gives token-protected HTTPS on 50 ports and a 60fps desktop agents can click.
Use boat when your own code starts machines for agents that do real work for hours: Docker, emulators, a browser and servers people reach, with the coding agents and their keys already set up. Compare it one to one: boat vs Replit and boat vs Together Code Sandbox.
Questions people ask
Is Replit cheaper than Together Code Sandbox?
It depends on the job, and neither fits our scenarios as is. Together's Code Interpreter is lower for one agent on workdays ($5 against $122) and 50 agents ($264 against $1,330), but higher for sandboxes for your users ($900 against $403) and 1,000 short jobs ($6,000 against $825). boat comes to $20, $317, $200 and $2,000 for the same four.
Which is faster, Replit or Together Code Sandbox?
We do not know. Neither is in StarSling's public benchmark, where boat did 26.69 Node.js runs per second at 4 vCPU / 8 GB, so there is no measured number to compare.
Can Replit or Together Code Sandbox run Docker?
Neither documents it. Replit sets up environments with Nix packages, and Together builds sandboxes from Docker images but does not document running Docker inside one. Every boat sandbox has Docker, systemd, root and /dev/kvm.
Can I start sandboxes from my own code?
On Together, yes, through the together-sandbox SDK and CLI once Together enables them for your organization. Replit has no API to start many machines; its MCP server creates and publishes apps through Replit Agent. On boat you sign up and create, stop and fork sandboxes by API, SDK or CLI.
What is the difference between Together Code Sandbox and Code Interpreter?
Code Sandbox gives you VMs started from Docker-image snapshots, with commands, files and memory snapshots, and must be enabled for your organization. Code Interpreter is a simpler API that runs Python code in a session, billed per 60 minutes.
Is boat SOC 2 compliant?
SOC 2 is in progress. We're open about where we stand: live status at status.ascii.dev and our data retention policy at docs.boat.dev/data-retention.
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