Convert HEIC to JPG under 100 KB

The usual failure chain

You AirDrop a photo. A Windows PC shows a blank icon or a third-party app. You “open with” something that exports a 4 MB JPG. The form then says maximum 100 KB. You screenshot the JPG, which makes a PNG, which is worse. ExactKB exists so that chain stops at step one.

Do this instead

1. On the iPhone, open HEIC to JPG in Safari or Chrome.
2. Pick the photo from the library. Granting Photos access sends the bytes to the page, not to a server.
3. Leave the target at 100 KB (or 50 KB for PAN/SSC).
4. Download the JPG. Files app will show a number at or under the target.

On a computer, the same page accepts a dropped .heic. Conversion uses a WASM HEIF decoder bundled with the site. After the first page load you can even toggle airplane mode and finish the job — there is no convert API to call.

Why “Save as JPEG” in Photos is not enough

iOS can export JPEG, and that solves the format error. It does not solve the kilobyte error. Mail’s “Medium” size is a guess. ExactKB’s 100 KB target is a contract with the validator.

Live Photos, bursts, and odd HEICs

A small number of files (burst covers, some edited Live Photos) fail in-browser HEIF decode. If you see an error, open the image in Photos, duplicate it as a still, or share it as JPEG from the share sheet, then drop that JPEG on the 100 KB tool. The compressor path no longer needs the WASM decoder.

Settings that create the HEIC problem

On iPhone, Settings → Camera → Formats → “Most Compatible” stores JPEG in Camera going forward. That prevents the next rejection; it does not fix the photos already on the roll. Those remaining HEICs are exactly what this page is for. Do not toggle the setting, screenshot the old HEIC, and upload the screenshot.

iCloud Photos can also present a “placeholder” until the full HEIC downloads. If ExactKB errors on a 200 KB file named IMG_1234.HEIC, wait for iCloud to finish, or open the image once in Photos so the original lands on disk, then retry. A 200 KB HEIC that is actually a cloud stub will fail decode in any local tool, not just this one.

Windows still sees a blank icon

A blank thumbnail in Explorer does not mean the file is corrupt. It means Windows has no HEIF codec. Drop the file on HEIC to JPG anyway. If your browser can run this site, it can run the WASM decoder. Installing Microsoft’s HEIF extension is optional and unrelated to ExactKB.

Privacy for ID HEICs

Passport and exam photos often include GPS if Location was on in Camera. Canvas redraw drops that metadata. We still recommend you do not email the HEIC to a friend “just to convert it.” Use this page or the share-as-JPEG sheet on the same phone. The privacy policy states that image bytes are not uploaded to ExactKB.

If you are converting a roll of mixed HEICs (family photos plus one exam portrait), process the exam portrait alone. Batch ZIP is available and still local, but you do not need to encode a holiday album to submit one JPEG.