Replit vs Islo
Replit is an AI app builder: you describe an app, Replit Agent writes it, and Replit hosts it. Islo is an agent sandbox: your code starts a microVM for each coding agent, with outbound traffic and keys handled at a gateway.
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.
Islo
Islo is an agent sandbox from Incredibuild: each coding agent gets its own microVM, with network rules and credentials handled at a gateway.
An Islo sandbox is a Linux microVM with its own kernel, built from a container image, with Claude Code, Cursor CLI and Codex preinstalled. Outbound traffic can pass through a gateway that allows or blocks hosts, injects credentials and logs every request. It is built for teams that run coding agents, evals and RL rollouts in the background, on Islo's cloud or in their own cloud account.
- Launched
- May 4, 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 | Islo: price rank | boat: price rank |
|---|---|---|---|
| Software factory 100 at once · 4 vCPU / 8 GB · 2,200 sessions of 8 h a month Replit drives one app at a time through Replit Agent, while Islo runs Docker in each microVM; neither documents /dev/kvm or a desktop, which boat has on every machine. | 181st of 367, with limits $2,000 a month | 326th of 367, with limits $7,402 a month | 3rd cheapest of 367 $634 a month |
| Always-on AI employees 50 machines 24/7 · 2 vCPU / 4 GB Islo fits an always-on assistant and can pause it with memory between tasks, while on Replit it has to be a Reserved VM, one published app billed all month. | 202nd of 366, with limits $2,033 a month | 30th cheapest of 366 $9,928 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 | 228th of 345, with limits $146 a month | 153rd of 345, with limits $503 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 Islo's Team plan is reported at 50 running sandboxes, so 300 for your users needs boat or a custom deal. | 233rd of 361, with limits $825 a month | 171st of 361, with limits $3,160 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 | 167th of 360, with limits $15,265 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 Islo has a built-in Harbor integration and gateway rules that keep trials from looking up answers; Replit has no API to start one machine per trial. | 265th of 364, with limits $685 a month | 198th of 364, with limits $2,456 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 Islo runs Docker inside its microVMs, so container builds work there; Replit's Nix-based environments do not document Docker. | 275th of 377, with limits $425 a month | 119th cheapest of 377 $1,507 a month | 4th cheapest of 377 $86 a month |
| 24/7 dev boxes 1 machine 24/7 · 4 vCPU / 8 GB Islo keeps a VM with root and Docker running as long as you like, while a Replit workspace is built for coding by hand, with no Docker or systemd. | 165th of 368, with limits $109 a month | 112th cheapest of 368 $402 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 Islo sandboxes are headless, so neither gives an agent a screen to click; boat streams a 60fps desktop with a computer-use API. | 190th of 369, with limits $619 a month | 310th of 369, with limits $2,210 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 | 113th of 367, with limits $1,105 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 Islo fits scraping at startup scale with open internet and long sessions; on Replit a bot is a published app. | 234th of 346, with limits $217 a month | 66th cheapest of 346 $748 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 | 265th of 338, with limits $14,966 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 | 47th of 360, with limits $746 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 | Islo | boat |
|---|---|---|---|
| Kind of product | AI app builder with browser workspaces and app hosting | Agent sandbox: a microVM per coding agent, started by API or CLI | Sandboxes you create, stop and fork by API, SDK or CLI |
| Isolation | Not documented; the security page says strong logical separation between users | Every sandbox is a microVM with its own kernel | 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 and CLI to create, pause, snapshot and delete sandboxes | API, SDK and CLI to create, stop, resume and fork many sandboxes |
| Docker and nested virtualization | System packages come from Nix; the docs do not describe Docker, systemd or /dev/kvm | Docker inside and sudo; no /dev/kvm or nested virtualization documented | Docker, root, systemd and /dev/kvm on every machine |
| Idle without paying | Autoscale apps wake on the first request and go idle after 15 minutes, costing nothing while idle | Pause keeps files, processes and memory; can pause after idle time and resume on the next exec, file access or webhook | Snapshots every minute and on stop; a stopped sandbox costs nothing; resume reboots from disk |
| Fork | Agent checkpoints at milestones you can roll back to | Snapshot a running sandbox's files, then start new sandboxes from it | Fork a running sandbox into new ones |
| Coding agents | Replit Agent, which you can also drive from an MCP client (create, update, ask, publish) | Claude Code, Cursor CLI and Codex preinstalled; factory lines run agent steps with events, steer and follow-ups | 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 | Gateway injects stored credentials into outbound requests for any host; credentials never reach the sandbox | AI credentials proxy for model providers and any HTTPS API you register; switch a credential to another account when credits run out |
| Desktop and computer use | VNC pane that streams a native desktop to your browser; no computer-use API | A browser inside the sandbox for testing; no desktop or computer-use API | 60fps desktop and Chromium, computer use and browser control, embeddable stream |
| Reaching the machine | Published apps on HTTPS domains, custom domains and private deployments; SSH into the workspace on paid plans | HTTPS share links that anyone with the URL can open, expiring after 24 hours by default; SSH and port-forward through the CLI | HTTPS URLs for up to 50 ports, token-protected; raw TCP; its own IP; SSH |
| Outbound internet rules | Open internet; no per-host allowlist documented | Gateway profiles allow or deny by host, path and HTTP method, with default deny and per-request logs | Open internet on every plan; no provider-side allowlist |
| Databases and storage | Postgres and App Storage built into each app | No hosted databases; run your own inside a sandbox | No hosted databases; run your own inside a sandbox |
| Machines at once | Not published for deployments; Pro allows 10 parallel agents | Free 5 and Team 50 running sandboxes per launch coverage; paused ones do not count | 100 to 2,000 running sandboxes by plan, raised by adding seats |
| Where it runs | Data mainly in Google Cloud in the United States; apps can publish in North America, Europe, Asia, South America or Australia | US West, or inside your own cloud account with BYOC | EU only: Germany, Finland, France; EU data residency and zero data retention |
Every feature Battleships tracks (43)
| Feature | Replit | Islo | boat |
|---|---|---|---|
| Full VM (own kernel) | Yes | Yes | Yes |
| Docker inside | No | Yes | Yes |
| Nested virtualization | No | No | Yes |
| Root | Not published | Yes | 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 | 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 | 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 | No | No |
| GPU | No | No | No |
| Windows | No | No | No |
| Arm64 | Not published | No | No |
| Self-hosting | No | No | 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 | Yes | Yes |
| Audit logs | Yes | Yes | No |
| SSO | Yes | Yes | No |
| SOC 2 | Yes | Not published | No |
| HIPAA | No | Not published | No |
| EU data residency | Yes | No | Yes |
| Zero data retention | Not published | Not published | Yes |
Performance
There is no comparable measurement for Replit or Islo: neither is in StarSling's public sandbox benchmark, so we cannot say which of the two is faster. In StarSling's run of 2026-09-29, boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB on dedicated AMD Ryzen 9 9950X hosts.
Node.js build-and-test loop at 4 vCPU / 8 GB, higher is better. Measured with the open hpc-sandbox-benchmarks suite. Replit and Islo 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 | Islo, 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 | $101 · Free | $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 | $420 · Free | $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 | $4,863 · Team | $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 | $1,382 · Team · 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 | $3,053 · Team · 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 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.
Islo: Islo bills each CPU core and each GB of memory and disk while a sandbox runs, with no plan fee. An idle sandbox keeps billing until a pause-after-idle timer fires, that timer can only be set at creation, and egress has no published price.
Islo: You pick a monthly plan from $20, and all of it becomes 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 agent is a published Reserved VM that bills all month, Docker and a reliable disk in a published app are not documented, and how many deployments can run at once is not published. Islo fits the single-agent and 50-agent scenarios, but its Team plan is reported at 50 running sandboxes, so 300 sandboxes for your users and 1,000 short jobs at once need a custom contract. Islo publishes no egress price, so its totals leave egress out. 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 | Islo | 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, storage, 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 a domain.
- Databases and storage included. Useful for a web app that needs data: each Replit app gets Postgres and App Storage next to it.
- Hosting that sleeps when idle. Useful for web apps with uneven traffic: Autoscale wakes on the first request and costs nothing while idle.
Use Islo when
your code runs coding agents in the background and you need per-host egress rules with a log of every call, pause with memory, or a US region or your own cloud account.
- A microVM per agent, by API. Useful if your code starts agents: each Islo sandbox is a microVM with Docker and Claude Code, Cursor CLI and Codex preinstalled.
- Egress rules and request logs. Useful if you must control what agents reach: Islo allows or blocks each host, path and method, and logs every call.
- Pause with memory, wake on request. Useful for agents that sit idle between tasks: Islo pauses them with memory kept and resumes on the next request.
Where boat fits
If what you are really running is agents, Replit is the wrong shape: it builds and hosts apps, and it has no API to start a machine per task. Islo fits that job, but its sandboxes are headless, have no /dev/kvm and are reported at 50 running at once on Team. boat gives each agent a full VM with a desktop, /dev/kvm and ports you can host on, with up to 2,000 at once in the EU.
A desktop agents can see and use
Replit's VNC pane shows a desktop to a person, with no API for an agent to click, and Islo sandboxes are headless. On Islo you would build a VNC stack and a control layer into each image yourself.
Docker, systemd and /dev/kvm
Replit's Nix environments do not document Docker or systemd, so a docker compose job has nowhere to run. Islo runs Docker, but with no /dev/kvm an Android emulator or a nested VM stops at boot.
Many machines, stable addresses
Replit has no API to start many machines, and Islo's Team plan is reported at 50 running sandboxes, with share links anyone can open that expire after 24 hours. boat runs up to 2,000 with token-protected HTTPS on 50 ports and raw TCP.
Use boat when your agents need more than a shell: a full VM with a desktop for computer use, /dev/kvm for emulators, ports you can host on, and up to 2,000 sandboxes at once in the EU. Compare it one to one: boat vs Replit and boat vs Islo.
Questions people ask
Is Replit cheaper than Islo?
It depends on the job, and Replit fits none of our agent scenarios because each always-on machine is a published Reserved VM. One coding agent on workdays is $101 a month on Islo and $122 on Replit, while one agent running all month is $122 on Replit and $420 on Islo. boat comes to $20 and $26 for the same two.
Which is faster, Replit or Islo?
We cannot say: neither Replit nor Islo is in StarSling's public sandbox benchmark or the other public results we use. boat did 26.69 Node.js build-and-test runs per second at 4 vCPU / 8 GB in that benchmark.
Can Replit or Islo run Docker?
Islo runs Docker inside its microVMs with sudo. Replit's docs set up environments with Nix packages and do not describe running Docker in a workspace or a published app. boat has Docker, root, systemd and /dev/kvm on every machine.
Is Replit a sandbox for AI agents like Islo?
Not in the same sense. Replit is an app builder where Replit Agent writes and publishes apps, and its outside entry point is an MCP server that drives Replit Agent. Islo is built for your code to start a microVM per agent, with Claude Code, Cursor CLI and Codex preinstalled.
Do Replit or Islo have a desktop for computer use?
Replit has a VNC pane that shows a desktop to a person in the workspace, and Islo sandboxes are headless with a browser for testing. Neither documents a computer-use API. boat streams a 60fps desktop with Chromium and a computer-use API on every sandbox.
Where does my data 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. Islo runs in US West or inside your own cloud account. boat runs only in the EU, with EU data residency and a zero data retention option.
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