About LocalJPG

A file converter that actually respects your privacy.

Why LocalJPG exists

Every mainstream image converter sends your photos to a server. That means your personal photos — from your iPhone, your family events, your work — travel to a stranger's computer to be “converted” and then hopefully deleted.

LocalJPG was built on a different premise: conversion should happen where your files already are — on your device. Modern browsers are powerful enough to do this with WebAssembly. We use that capability instead of asking for your files.

How it works

When you drop a file into LocalJPG, your browser downloads the conversion engine once (a WebAssembly binary, cached for future visits) and runs it locally. Your photos never leave your tab.

100% on-device

WebAssembly runs the converter inside your browser. No file is ever uploaded.

MozJPEG quality

We use MozJPEG — the same encoder Mozilla uses — for 10–15% smaller files at the same visual quality.

EXIF preserved

Date taken, GPS location, camera model, and orientation are kept in every output JPG.

Supported formats

HEIC / HEIF — iPhone default photo format since iOS 11
WebP — modern web image format from Google
ZIP archives — drop a .zip containing HEIC or WebP files, all are converted at once

Technology

WebAssemblyEnables near-native performance in the browser. The conversion engine runs at compiled-code speed without any server.

MozJPEGMozilla's JPEG encoder. Uses advanced compression techniques (trellis quantization, progressive encoding) to produce smaller files than standard libjpeg.

libheifOpen-source HEIC/HEIF decoder. Used to read Apple's High Efficiency Image Format.

jsquashWebAssembly build of the codec suite. Bridges the C encoders/decoders to the browser's JavaScript environment.

fflateHigh-performance JavaScript zip library. Streams your converted JPGs into a ZIP archive entirely in-browser, without any server.

Cloudflare PagesStatic hosting with global CDN. The entire app is a static bundle — there is no application server.

Pricing

Single file conversion is always free. For batch downloads, you can pay once to get all your converted files as a ZIP — no subscription, no account, no usage limits.

1 file, any size

Free

2+ files, one at a time

Always free

2+ files as ZIPApple Pay · Visa · Mastercard

$5 one-time

2+ files as ZIPTON cryptocurrency

$0.50 one-time

Who built this

Built by an indie developer frustrated by converters that upload your files. The goal was simple: use WebAssembly to move the conversion entirely onto the device, so there is nothing to trust and nothing to breach.

Ready to convert your photos?

Start converting