Val Town

Val Town — Deno isolates that run TypeScript on HTTP, cron and email triggers. Val Town runs small TypeScript programs in Deno isolates with HTTP, cron and email triggers, plus built-in SQLite and blob storage. It is not a general sandbox — no root, no Docker, no long-running processes — but for evaluating a snippet of model-generated TypeScript behind an HTTP endpoint it starts faster and costs less than anything with a kernel. Treat it as the isolate end of the spectrum. Founded 2022. Seed.

We track it in 1 comparison — Sandbox providers — so every claim below is a cell in a table you can open and check rather than an impression. Across those rosters it sits against 19 other tools, and what follows is where it visibly separates from them.

Where it wins.

• Cold start — 150 ms, 2nd of 16.
• Idle cost — free-when-stopped, tied for best across 5 of 16 tools.
• MCP server — Yes, which only 4 of 16 tools here manage.

Each of those is ranked against the whole roster on its category page, not against a hand-picked subset, so a first place here means first of everything we list.

Where it gives ground.

• Snapshot & fork — No. Daytona records Yes.
• Custom images — No. E2B records Yes.
• Persistent FS — No. Modal records Yes.
• Max runtime — 5 min, 15th of 16. E2B records 1440 min.

None of these disqualify it on their own. They are the fields to check against your own requirements before you commit, because they are the ones where a competitor genuinely does better.

Provenance. 22 of 26 tracked fields carry a value for Val Town, and 6 of those cite a document you can open. Last verified 2026-01-15. Every figure keeps its own provenance — measured by us, claimed by the vendor, inferred, or community-reported — and we would rather print a dash than a guess.

Its nearest neighbour in our data is ascii. Val Town is ahead on Preview URLs (Yes against Partial). ascii takes Root in guest (Yes against No) and Snapshot & fork (Partial against No). That pattern repeats across the rest of the roster — see Val Town alternatives for the other rivals, each compared the same way.

Founded

2022

Funding

Seed

Fields we track

22 of 26

Last verified

2026-01-15

Here as the isolate benchmark: no kernel, no filesystem, no shell, and consequently the fastest and cheapest way to run a snippet of model-written TypeScript behind a URL. The moment your agent needs to run npm install and inspect the result, you have outgrown it.

Cold start

150 ms2nd of 16

Inferred

Snapshot & fork

○No15th of 18

Inferred

Custom images

○No18th of 20

Vendor-claimedverified 2026-01-15source

Idle cost

free-when-stopped1st of 16

Inferred

Persistent FS

○No14th of 16

Vendor-claimedverified 2026-01-15source

MCP server

●Yes1st of 16

Inferred

Max runtime

5 min15th of 16

Inferred

Root in guest

○No19th of 20

Vendor-claimedverified 2026-01-15source

Val Town is the right call in these situations, each one drawn from a field we actually record:

• Evaluating short TypeScript snippets behind an HTTP endpoint.
• Cron and webhook glue an agent can write and deploy itself.
• Zero infrastructure, and you can accept zero filesystem.
• Cold start is your binding constraint. Val Town records 150 ms, 2nd of 16 in the Sandbox providers roster. We define that field as p50 wall-clock from a single client in a fixed region calling create-sandbox on an account with nothing running, until a trivial command returns output.
• Idle cost is your binding constraint. Val Town records free-when-stopped, the best figure in the Sandbox providers roster. We define that field as what you pay while a sandbox exists but is doing nothing — the common case when an agent is blocked on model inference.
• MCP server is your binding constraint. Val Town records Yes, which only 4 of the 16 tools in the Sandbox providers roster do.

Reach for something else when any of the following is a requirement rather than a nice-to-have:

• Snapshot & fork. Val Town records No on the Sandbox providers table. Daytona records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Custom images. Val Town records No on the Sandbox providers table. E2B records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Persistent FS. Val Town records No on the Sandbox providers table. Modal records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Max runtime. Val Town records 5 min, 15th of 16 in the Sandbox providers roster. E2B records 1440 min on the same field. If that is a hard requirement rather than a preference, start elsewhere.
• Root in guest. Val Town records No on the Sandbox providers table. E2B records Yes on the same field. If that is a hard requirement rather than a preference, start elsewhere.

We publish this block because a comparison that only lists what a tool is good at is marketing. Every figure above sits on the same page as its source, and the field definitions are on the category tables if you want to check how we measured them.

What we don't know. 4 of the 26 fields we track for Val Town are still blank: Cold start (claimed), Concurrent limit, Price / hour and GitHub stars. Those render as dashes rather than as zeroes or assumptions, because an empty cell and a bad cell are not the same thing and only one of them is honest. If you know any of these figures and can point at a document, tell us.