Checking latest build... • Offline & Open Source

Stop uploading private files to random websites.

Jontro is your local Swiss Army knife. Convert videos, extract OCR text, slice PDFs, crop photos, and trace vectors natively on your CPU & RAM — with zero telemetry and zero cloud uploads.

100% Free Forever No Signups · No Accounts Native Silicon Speed
Download Windows

Windows 10/11 • 64-bit (.exe)
Download macOS

Apple Silicon & Intel (.dmg)
Portable • No installation required • View all release assets on GitHub →

8 Built-in Powerhouses

No internet connection needed. No rate limits. Every tool runs locally with native execution queues to keep your system smooth.

Video to Audio

FFmpeg

Batch extract pristine MP3s from MP4, MKV, AVI, and MOV. Protects system responsiveness via a native serial queue with optional EBU R128 loudness normalization.

OCR & PDF Scanner

WASM Neural

Hit Ctrl+V to paste a screenshot and pull text immediately. Supports multi-page PDFs and English + Bengali bilingual OCR.

PDF Toolkit

In-Memory

Merge unlimited PDFs, isolate complex page ranges (e.g. 1, 3, 5-12), and rasterize documents to high-res PNGs without uploading sensitive contracts.

Image Cropper & Resizer

HTML5 Canvas

Lock aspect ratios, pan, zoom, and export instantly to WEBP, JPEG, or PNG with custom compression settings and zero quality loss.

Vector Tracer

Algorithmic

Convert pixelated PNGs and JPGs into infinitely scalable, clean SVG vectors using localized polygon-tracing presets without subscription fees.

QR Studio

SVG Export

Generate production-ready QR codes with custom foregrounds, embedded center logos, error correction, and background excavation.

Password Generator

Crypto API

Generate cryptographically robust passwords using OS hardware entropy pools (crypto.getRandomValues) with instant zxcvbn strength scoring.

Smart Task Manager

Local Cache

A focused to-do companion that detects urgency and deadline priorities straight from natural language without cloud syncing.

0-Telemetry Guarantee

Your files never leave your computer. Period.

Most "free online converters" upload your sensitive PDFs, invoices, and family videos to unverified cloud servers to monetize your data. Jontro bundles the real binaries and neural models directly inside the application bundle. All computations occur in local RAM with zero network pings.

• No Sentry/Loggers • No Tracking Cookies • 100% Offline Capable