An experimental WebAssembly port of the JSON-stat parsing logic that powers the JSON-stat JavaScript Toolkit.
It does not aim to be a full clone of the toolkit. Instead, it mimics the main subset of methods that the toolkit exposes, but implemented in Rust and compiled to WASM. The idea is to explore whether the toolkit's day-to-day API can be delivered with WASM-level speed and a tiny footprint, while keeping usage familiar to anyone who already knows the toolkit.
⚠️ This is a work in progress and an experiment. The API may change, and not every toolkit feature is available yet. See What is implemented and the API reference for the current scope.
- What is JSON-stat?
- What is implemented
- Try it in a webpage (simple version)
- How it works
- Documentation
- License
JSON-stat is a simple, open format for statistical data. Statistical offices around the world publish datasets (population, economy, unemployment, etc.) as JSON-stat documents. Reading one of those documents in the browser — turning it into something you can query and display — is exactly the job the JSON-stat Toolkit (and this experiment) is built for.
This package exposes the toolkit-style entry point and the core methods you use most often:
JSONstat(input)— create a dataset instance from a JSON-stat string, object, or URL (fetched for you).- Traversing:
Dimension(),Category(),Data(),Item(). - Transforming:
Transform(),Unflatten(),Dice()(subsetting/filtering). - Export / round-trip:
ToJSON().
For the full, precise list of methods and properties, see the API reference.
The easiest way to use jsonstat-wasm is to load it straight from a
CDN — no download,
no build step, no package manager. You only need a plain .html file.
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<title>jsonstat-wasm demo</title>
</head>
<body>
<h1>jsonstat-wasm demo</h1>
<pre id="output">Loading…</pre>
<script type="module">
// 1. Import JSONstat from a CDN (in production, pin to a proven
// specific version instead of @latest for safety).
// jsDelivr (default):
import { JSONstat }
from 'https://cdn.jsdelivr.net/npm/jsonstat-wasm@latest/jsonstat.js';
// …or unpkg (choose either one):
// import { JSONstat }
// from 'https://unpkg.com/jsonstat-wasm@latest/jsonstat.js';
// 2. Point at any JSON-stat dataset (here, the OECD sample).
const url = 'https://json-stat.org/samples/oecd.json';
// 3. Fetch + parse it in one call. JSONstat() returns a Promise.
const ds = await JSONstat(url);
// 4. Read some basic information about the dataset.
const
label = ds.label, // dataset title
dims = ds.id, // array of dimension IDs
n = ds.n // number of data values
;
// 5. Look up a dimension and a category, just like the toolkit.
const
geoDim = ds.Dimension('concept'), // a dimension by ID
firstLabel = geoDim.Category(0).label // first category's label
;
document.getElementById('output').textContent =
`Dataset: ${label}\n` +
`Dimensions: ${dims.join(', ')}\n` +
`Number of values: ${n}\n` +
`First category of "concept": ${firstLabel}`;
</script>
</body>
</html>Browsers block import and fetch() when you open a file directly
(file://...), so serve the folder over HTTP. Any static server works:
# Python (already installed on most systems)
python3 -m http.server 8080
# …or with Node.js (no install needed)
npx serve .Then visit http://localhost:8080 in your browser. You should see the dataset title, its dimensions, and the number of data values.
From here you can explore the dataset with the methods in the
API reference — for example ds.Data(0).value to read the
first value, or ds.Dice({ ... }) to create a filtered subset.
Want to use it with npm, a bundler, or build it yourself from the Rust source? See the Installation guide.
The parsing and querying logic is written in Rust (see src/) and
compiled to a WebAssembly module. A thin JavaScript facade (jsonstat.js)
loads and initializes the WASM module automatically, then exposes a familiar
toolkit-style JSONstat() function. Because the heavy lifting happens in WASM,
parsing large datasets is fast, while the JavaScript you write stays simple.
- 📖 Installation guide — building from source, using with npm/bundlers, CDN usage, and the Rust library API.
- 📚 API reference — every method and property exposed by
the
JSONstatclass.
MIT © Xavier Badosa