xlsx-preview

Render .xlsx, .csv, and Parquet workbooks to a <canvas> or PNG — in the browser, in Node, or from the CLI. Published as @hewliyang/xlsx-preview.

npm install @hewliyang/xlsx-preview

browser

import { createWorkbookPreviewerFromFile } from "@hewliyang/xlsx-preview/browser";

await createWorkbookPreviewerFromFile(container, file);

The browser entry runs the Rust extractor as wasm inside a Web Worker, so the file never leaves the page. See the vanilla-js examples for both a no-build CDN demo and a Vite starter.

react

import { ExcelPreviewer } from "@hewliyang/xlsx-preview/react";

<ExcelPreviewer file={file} />;

See the framework starters for full minimal projects: react-vite and nextjs.

node

import {
  loadWorkbookFromCsv,
  loadWorkbookFromParquet,
  renderXlsxToPng,
} from "@hewliyang/xlsx-preview/node";
import { writeFile } from "node:fs/promises";

const png = await renderXlsxToPng("model.xlsx", { scale: 2 });
await writeFile("out.png", png);

const csvLayout = await loadWorkbookFromCsv("sales.csv");
const parquetLayout = await loadWorkbookFromParquet("events.parquet");

cli

xlsx-preview model.xlsx --info
xlsx-preview model.xlsx -o cover.png --sheet Cover --range B3:E12 --scale 2
xlsx-preview model.xlsx -o previews/{index}-{sheet}.png --all
xlsx-preview data.csv -o data.png --delimiter ","
xlsx-preview events.parquet -o events.png --max-rows 5000

examples

Live demos: https://xlcore.pages.dev.

For runnable examples and minimal starters, see packages/xlsx-preview/examples/.

development

This repo is a Rust workspace (the extractor + wasm + a xlcore CLI) plus the TypeScript renderer package.

xlsx
  │  ooxmlsdk (xlcore-io)
  ▼
SpreadsheetDocument (full OOXML tree, charts/CF/etc preserved verbatim)
  │  walk sheets/rows/cells, resolve fonts/fills/borders/numFmts;
  │  extract drawings + charts; resolve chart range refs
  ▼  (xlcore-export)
WorkbookLayout JSON  ──►  @hewliyang/xlsx-preview canvas renderer  ──►  <canvas> / PNG

Three runtime paths share the same render() core:

• In-browser end-to-end: createWorkbookPreviewerFromFile() runs xlcore-wasm inside a Web Worker and hands the JSON to the canvas renderer in the main thread. No server.
• Node / CLI: renderToPng() / renderXlsxToPng() use skia-canvas against the same render pass; the xlsx-preview bin shells out to it.
• Static HTML preview: xlcore preview <file.xlsx> (Rust CLI) extracts server-side and inlines { layout JSON (gzip+base64), renderer bundle } into one self-contained .html.

The JSON contract is generated from one source via ts-rs — Rust types in crates/xlcore-export/src/schema.rs produce the TS in packages/xlsx-preview/src/schema/. Regenerate after schema changes with cargo test --release -p xlcore-export export_bindings.

Contributor docs:

• docs/plan-excel-rust-lib.md — architecture and roadmap.
• docs/PARITY.md — feature-by-feature scoreboard against Excel / SpreadJS.
• docs/TESTING.md — fixture + visual-diff workflow.