Building a product import workflow? Start with the React importer guide. This page documents the lower-level conversion engine.

Developer quickstart

Convert structured data as a stream

Diakrio reads CSV, TSV, PSV, JSON, NDJSON, JSONL, YAML, XML, XLSX, XLS, and ODS locally. It writes CSV, JSON, NDJSON, and XML. Output bytes are delivered incrementally, so browser apps can write each chunk directly to disk instead of assembling a second full-file Blob.

Package and runtime

Package availability

Scoped release pending

@diakrio/converter

This scoped package has no verified public npm release as of 2026-09-18. You can try the locally built runtime on this site while the release is prepared.

The existing public package is convert-buddy-js 1.0.4. Its MIT license and API belong to that version; the scoped v2 examples target the published beta.

Free for personal and commercial application use. License and notices.

Use @diakrio/converter/browser for browser bundles and the package root for Node.js. Start with the browser file guide or the Node.js stream guide.

CSV to NDJSON

Run this site's locally built WASM preview against generated data and inspect measured throughput and memory on this device.

10,000 generated CSV records

import { ConvertBuddy } from '@diakrio/converter/browser';

const buddy = new ConvertBuddy({ profile: true });
const controller = buddy.stream(file, {
  inputFormat: 'csv',
  outputFormat: 'ndjson',
  onBytes: async (chunk) => {
    await writable.write(chunk); // backpressure is respected
  }
});

const stats = await controller.done;
console.table({
  mbPerSecond: stats.wallThroughputMbPerSec,
  recordsPerSecond: stats.recordsPerSec,
  peakEngineBufferBytes: stats.maxBufferSize
});

Measured on this device

Browser · WASM· preview discarded· idle

End-to-end

0.0 MB/s

Records/sec

Records

Duration

0 ms

Engine peak buffer

0 B

Runtime heap

Unavailable

Input

0 B

Output

0 B

Engine buffer is exact. Runtime heap is shown only when the runtime exposes a measurement API. Engine-only throughput: 0.0 MB/s.

Pick a use case

Browser filesDirect-to-disk output with a bounded-memory fallback.

Node.js streamsPipe files through Diakrio with backpressure.

Executable recipesRun common format conversions and compare metrics.

API referenceOptions, callbacks, controller methods, and stats.

Package and runtime

Package availability

Scoped release pending

@diakrio/converter

This scoped package has no verified public npm release as of 2026-09-18. You can try the locally built runtime on this site while the release is prepared.

The existing public package is convert-buddy-js 1.0.4. Its MIT license and API belong to that version; the scoped v2 examples target the published beta.

Free for personal and commercial application use. License and notices.

Use @diakrio/converter/browser for browser bundles and the package root for Node.js. Start with the browser file guide or the Node.js stream guide.

import { ConvertBuddy } from '@diakrio/converter/browser'; const buddy = new ConvertBuddy({ profile: true }); const controller = buddy.stream(file, { inputFormat: 'csv', outputFormat: 'ndjson', onBytes: async (chunk) => { await writable.write(chunk); // backpressure is respected } }); const stats = await controller.done; console.table({ mbPerSecond: stats.wallThroughputMbPerSec, recordsPerSecond: stats.recordsPerSec, peakEngineBufferBytes: stats.maxBufferSize });