What happens to your HEIC on this page
There is no setting to choose. Add the files, press the button, keep the PNGs.
A HEIC holds a still frame compressed the way H.265 video is compressed. Getting at that frame is the hard part, because only Safari carries the code for it: Apple licenses the decoder, and Chrome, Firefox and Edge refuse the file rather than pay for a codec covered by two patent pools. So the tool tries the browser's own decoder, and when it is turned down it downloads libheif built for WebAssembly (a 91 KB loader plus a 1.42 MB decoder, near 370 KB compressed) and runs it in a worker thread. That download happens on the first conversion of your visit and never again.
Out of the worker comes an array of raw pixels, four bytes each, and PNG writes every one of them without approximating anything. Measured on a 4032 × 3024 photo in Chrome: 0.65 seconds to decode, 0.5 more to write the PNG.
That same photo arrived as 2,043,192 bytes of HEIC and left as 19,050,660 bytes of PNG, nine times heavier. Storing every pixel is the whole job of the format, and it costs what it costs. The row under your download shows the finished size by itself, because a percentage beside it would suggest the tool damaged something.
When you'd reach for it
- An editor has to open it. GIMP, Krita, Inkscape, Paint.NET and a long tail of older Photoshop installs read PNG on any machine, with no plugin and no store purchase.
- The photo is going through several rounds of edits. Each JPEG save throws away a little more; a PNG you keep re-saving stays exactly as it was.
- You are cutting something out of the picture. Erasing a background needs an alpha channel to erase into. PNG carries one; JPEG has no such thing.
- A design tool, a slide or a document. Figma, Canva, Word and Keynote all place a PNG without asking questions about codecs.
- Screenshots and diagrams saved as HEIC. Flat color and hard edges are what PNG stores best, and what JPEG smears.
What this tool cannot do
There is no way back to HEIC. Reversing the trip needs an H.265 encoder, and encoding is where the licensing on this format has real teeth. No page here offers it, so treat the PNG as your working copy and keep the original in your camera roll.
Rotation stored in an Exif tag is ignored. Two places in a HEIC can say which way is up. The decoder honors the container property and skips the Exif field entirely, so a portrait photo whose camera used the Exif field arrives lying down. The fix is to turn it in the app that made it and export a fresh copy. Expect this one to catch you before any other limit here does.
Nothing but pixels survives. Shooting date, camera body, lens, exposure and GPS are all left in the original. The decoder here offers no way to read those fields, so there is nothing to copy across even if you wanted it.
Motion, depth and extra frames are left in the original. A Live Photo gives up its video, a burst gives up every frame but the main one, and a portrait shot gives up the depth map that made the blur.
Ten-bit color becomes eight-bit. HDR photos come through with their brightest and darkest parts squeezed toward the middle, which shows up first in skies and in bright windows.
An AVIF stops at the door. Both formats sit in the same kind of file, so the check reads the four-letter brands in the first 64 bytes and turns an AVIF away by its real name. It happens before the megabyte-and-a-half decoder is fetched, so a mistaken drop costs you nothing.
Photos above 100 megapixels are turned down. Decoding eats about nine bytes of memory per pixel and holds onto it, and a browser tab that runs out of memory dies without reporting anything, so the tool stops first and tells you why. No phone shoots anywhere near that ceiling, though a 48-megapixel file will make one work for it.
It converts, and that is all. Nothing here crops, straightens, resizes or retouches.
Frequently asked questions
Why is my PNG ten times the size of the HEIC?
Because the two formats are solving opposite problems. H.265 spends enormous effort predicting each block of the picture from its neighbors; PNG writes the pixels down and compresses the result losslessly, which on photographic noise gets nowhere. The photo measured above grew 9.3 times, and a ratio in that neighborhood is what to expect. If size matters more than editability, the JPG page is the one you want.
Should I use PNG or JPG for my phone photos?
PNG when the picture is heading into an editor or needs a transparent area. JPG for anything you are sending, uploading or attaching. Most people looking for a HEIC converter want the second one.
Is any quality lost?
Between the decoder and the file, nothing: every pixel handed over gets written down. The losses that exist happened before this page saw the photo, when your camera compressed it, plus one more when 10-bit color is squeezed into 8.
Does the photo leave my device?
Never. The two decoder files travel toward you and the picture stays in the tab. The site is static hosting with no upload endpoint anywhere in it.
How many can I do at once?
As many as you can select. They run in sequence so a phone does not run out of memory, and the button beneath the list packs the finished files into one zip.
Does the file name survive?
Yes, apart from the extension. IMG_4821.HEIC becomes IMG_4821.png, and .heif is treated the same way.
Credits and license
Two libraries do the decoding, and both belong to other people. They are licensed under the GNU Lesser General Public License v3.0 and ship here as their authors published them:
- libheif 1.23.2 parses the file and locates the primary image. Its home is github.com/strukturag/libheif, and the browser build comes from the libheif-js package.
- libde265 1.0.15 is the H.265 decoder libheif calls to turn the compressed frame into pixels. Its home is github.com/strukturag/libde265.
Their license sits beside the binaries at /libheif/LICENSE.txt. The LGPL asks that the library stay replaceable, which it is: the WebAssembly file is loaded by URL and swapping it for your own build takes one file.