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How to convert HEIC to JPG using JavaScript

How to Convert HEIC Images to JPG Using Pure JavaScript (Client-Side)

Apple devices like iPhones and iPads save photos in the HEIC format by default. While HEIC is efficient in terms of file size and quality, it often causes compatibility issues when uploading images to websites, sharing on certain platforms, or opening files on non-Apple systems.

In this post, I’ll explain:

What HEIC is and why it causes problems

Why client-side conversion is better than server uploads

How browser-based HEIC to JPG conversion works

A working online demo you can try instantly

What is HEIC and Why It’s a Problem

HEIC (High Efficiency Image Container) is based on the HEVC compression standard. Apple introduced it to reduce file size while maintaining high quality.

However, HEIC has limitations:

Not supported by many websites

Older Windows systems can’t open it by default

Some apps (WhatsApp, CMS platforms, email tools) reject HEIC uploads

Because of this, JPG is still the most universally accepted format.

Why Convert HEIC to JPG in the Browser?

Most online converters upload your images to a server. This has drawbacks:

Privacy concerns (your photos leave your device)

Slow uploads for large images

Server costs and storage limits

Client-side conversion solves this

Modern browsers are powerful enough to:

Read HEIC files

Convert them to JPG

Download the result instantly
All without uploading files to a server.

How Client-Side HEIC Conversion Works

At a high level, the process looks like this:

User selects a HEIC file

JavaScript reads the file using the File API

The image is decoded using a HEIC-compatible library

The image is rendered onto a canvas

Canvas exports the image as JPG

User downloads the converted file

This approach is:

Fast

Secure

Scalable

Cost-effective

Example: Browser-Based HEIC to JPG Tool

I built a small browser-based tool that converts HEIC images to JPG entirely on the client side. No file uploads, no sign-up, no tracking.

You can try the working demo here:
👉 https://www.simplefiletools.com/heic-to-jpg

It works on:

iPhone

Android

macOS

Windows

Any modern browser

When Client-Side Conversion Makes Sense

This approach is ideal when:

You’re building privacy-first tools

You want to avoid backend complexity

You expect high traffic without server load

You’re handling user-generated files

For heavy batch processing or very large images, server-side tools may still be useful—but for most everyday use cases, browser-based conversion is more than enough.

Final Thoughts

HEIC is a great format, but JPG remains the most compatible choice for sharing and uploads. With modern JavaScript and browser APIs, converting images directly in the browser is both practical and user-friendly.

If you’re building file tools or working with image uploads, client-side conversion is definitely worth considering.

Resources

HEIC to JPG Online Converter (Client-Side):
https://www.simplefiletools.com/heic-to-jpg

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