If you've ever tried to share an iPhone photo with someone on Windows, upload one to an older website, or attach one to an email and had it rejected as 'unsupported,' you've met HEIC. It's the format Apple has used by default since iOS 11, and while it produces beautifully small files, the rest of the world hasn't fully caught up.
The fix is to convert HEIC to JPG, which any device on Earth can read. The catch is that most online HEIC-to-JPG converters work by uploading your photos to a server you've never heard of — which is a strange tradeoff for what should be a 5-second task. This guide shows you how to convert HEIC to JPG entirely in your browser, with nothing leaving your device.
Why HEIC is annoying (and why iPhones use it anyway)
HEIC's compression is genuinely impressive: at the same visual quality, a HEIC file is roughly half the size of the equivalent JPEG. On a phone with thousands of photos, that's a meaningful storage win. HEIC also supports things JPEG can't: 16-bit colour depth, transparency, multiple images per file (used for Live Photos), and HDR.
The downside is compatibility. JPEG has been universal since 1992. HEIC was standardised in 2015 and only started shipping by default on iPhones in 2017. Half the software ecosystem still trips over it:
- Older Windows installations need a separately-purchased codec extension to view HEIC.
- Many web upload forms (job application sites, government portals, older CMS platforms) reject HEIC.
- Some older photo editing tools and printing services don't accept it.
- Sharing to a non-Apple device often results in 'Why can't I open this?' messages.
iPhones partially work around this: when you AirDrop a HEIC photo to a Mac it stays as HEIC, but when you share via Mail or upload to a non-Apple service iOS often converts to JPEG automatically. The conversion isn't always reliable, though, and sometimes you end up with a HEIC anyway.
Convert HEIC to JPG in your browser
The browser-based way is the fastest and most private. Here's the step-by-step:
- Open a privacy-respecting converter that handles HEIC natively (ImagePal's converter is one).
- Drag your HEIC file (or a folder of them) into the upload area.
- Select 'JPG' (or 'JPEG' — they're the same format) as the output.
- Choose a quality setting. 90 is a safe default that preserves the original quality almost perfectly. 75 gives smaller files at slightly lower fidelity.
- Click convert and download. The whole conversion runs locally — nothing is uploaded.
Bulk-converting a folder of HEIC photos
Most browser-based converters handle batches. Drop in 50 HEIC files at once and they'll convert in parallel using your CPU's cores (a Web Worker per image, typically). For a few hundred photos, this is faster than any online tool — there's no upload bottleneck.
If you have thousands of photos to convert (say, an entire Photos library), browser-based may hit memory limits. In that case, dedicated desktop tools are better: Preview on macOS can batch-export to JPEG, and on Windows, IrfanView or XnConvert handle large HEIC batches well.
Stop your iPhone from saving HEIC in the future
If you regularly need to share photos with non-Apple users, change the default once and forget about it:
- Open Settings on your iPhone.
- Tap Camera.
- Tap Formats.
- Choose 'Most Compatible' instead of 'High Efficiency.'
Future photos will be saved directly as JPEG. Existing HEIC photos in your library aren't converted retroactively — you'll need to convert them manually.
What about quality and file size?
When you convert HEIC to JPG, two things change:
- Quality drops slightly. JPEG's lossy compression discards a small amount of detail that the HEIC version preserved. At quality 90+, this is essentially invisible. At quality 75, you might see slightly more compression artifacts in shadow areas.
- File size goes up. A 2.5MB HEIC file typically becomes a 4–5MB JPEG at quality 90, or 2–3MB at quality 75. There's no way around this — JPEG just stores the same image less efficiently.
Recommended settings:
- For sharing or uploading: quality 85–90. Almost zero visible loss, files are reasonable.
- For web use (blog post, article): quality 75. Smaller files, still looks great at normal viewing sizes.
- For printing or archival: quality 95+ or consider TIFF for true lossless.
Why not just use online converters?
Most online HEIC-to-JPG converters work by uploading your photos to a server, processing them there, and giving you a download link. For a quick conversion of a non-sensitive image, that's fine. For personal photos — especially photos with EXIF GPS data attached — it's a meaningful privacy compromise. Your home address might be embedded in those vacation photos. The server gets a copy. The privacy policy promises 'temporary' storage, but you have no way to verify what 'temporary' means.
Browser-based converters do exactly the same job without that tradeoff. The browser already has the codecs it needs (or loads a small JavaScript HEIC decoder), the conversion runs on your device, and the file never leaves. There's no good reason to upload HEIC photos to a stranger's server in 2026.
The bottom line
HEIC is a great format that the rest of the world hasn't fully embraced. Until that changes, you'll occasionally need to convert. Do it in your browser, where the photos stay on your device, with the quality and privacy tradeoffs visible and under your control.