アップロードなしでHEICをJPGに変換：プライバシーガイド

When you use a typical online converter, your photos are uploaded to someone else’s server. Here’s why that matters and how to avoid it.

What Happens When You Upload HEIC Files

When you use services like CloudConvert, Zamzar, or iLoveIMG:

1. Your HEIC file gets uploaded via HTTP POST
2. It’s stored temporarily on their server
3. Their software converts it to JPEG
4. The JPEG is sent back to you
5. The original and converted files may persist on their servers

You have no control over how long they keep your files or who can access them.

The Privacy Risk

Photos often contain sensitive information:

• GPS coordinates — your home, workplace, frequent locations
• Faces — family members, children
• Documents — screenshots of IDs, receipts, contracts
• Timestamps — your daily routines and patterns

Uploading to an unknown server means trusting a third party with all of this.

How Client-Side Conversion Works

heicgo.com processes everything in your browser:

┌──────────────────────────────────────────────────┐
│              YOUR BROWSER (Local)                 │
│                                                   │
│  HEIC File → [EXIF Extract] → [Decode] →         │
│  [Canvas Process] → [JPEG Encode] →              │
│  [EXIF Inject] → Download                         │
│                                                   │
│  Files NEVER leave your device                    │
└──────────────────────────────────────────────────┘

The conversion uses WebAssembly (WASM) — a binary format that runs at near-native speed inside your browser’s sandboxed environment.

How to Verify No Upload

1. Open your browser’s Developer Tools (F12)
2. Go to the Network tab
3. Use heicgo.com to convert a file
4. Check the network requests — you’ll see only static files (JS, CSS), no file upload

Other Privacy Tips

• Always check the URL before uploading — look for HTTPS and a legitimate domain
• Avoid converters that ask you to create an account
• Be suspicious of “free” converters with no visible business model (they may sell data)
• Use heicgo.com — it’s ad-supported, so your data was never the product

Further Reading

• How to Convert HEIC to JPG — the privacy-first converter
• Cloud Storage vs Local Storage for Photos — where to keep your converted files
• Preserve EXIF Data When Converting HEIC — metadata privacy considerations