Format
HEIC, the photo format of the iPhone.
A HEIC file is a picture compressed with the same codec as modern video. It is small and rich, and it is the format an iPhone writes by default.
Flex Convert reads HEIC in Safari, and in Chrome or Edge where the computer can play HEVC video.
Facts
The record.
Extensions
.heic and .heif. A sequence of pictures in one file is .heics.
Container and codec
HEIF, a picture container standardised by MPEG, holding images compressed with HEVC (H.265).
Colour and depth
The format allows 10 bits per channel or more, wide colour such as Display P3, and room for depth maps and several pictures in one file.
Who writes it
iPhones and iPads since iOS 11, in the default High Efficiency setting.
Who reads it
Apple software natively. Windows needs a decoder add-on, and many websites and upload forms refuse it.
In Flex Convert
Read only: the file is decoded in your browser and written as JPG, PNG, WebP or AVIF. HEIC is never written.
Measured examples
What converting it showed.
Two generated 12-megapixel pictures, saved as HEIC by macOS, converted to JPG on this site.
| Test file | Size | Change | Time | Result |
|---|---|---|---|---|
| Detailed photo, 12 MPChrome | 1.3 MB → 1.5 MB | 17 percent larger | 1.8 s | 33.3 dB likeness · 4000 × 3000 · Location removed |
| Detailed photo, 12 MPWebKit | 1.3 MB → 1.6 MB | 24 percent larger | 2.8 s | 31.9 dB likeness · 4000 × 3000 · Location removed |
| Smooth gradients, 12 MPChrome | 74 kB → 97 kB | 32 percent larger | 1.2 s | 48.9 dB likeness · 4000 × 3000 · Location removed |
Measured on November 7, 2026 in Google Chrome 157, WebKit (Playwright build, not Safari) 26, on Apple M1 Pro. Times run from pressing Convert to the result being ready, with the page already loaded. Likeness is PSNR against the original: higher is closer, and above 40 dB the difference is hard to see. WebKit here is Playwright's build, which is not Safari. Every test file was generated for these measurements, none is anyone else's work, and each is described on the About page.
The busy photo went from 1.3 MB as HEIC to 1.5 MB as JPG; the smooth one from 74 kB to 97 kB. A JPG is usually the larger file for the same picture. Chrome took 1.8 seconds on the busy one and WebKit 2.8.
Good to know
What to know before you convert.
The format is simple to use and awkward to share, which is the whole story.
Why HEIC exists
Phone cameras made more pixels than JPG could store cheaply. HEIC keeps the same visible quality in a smaller file, which matters when a library holds tens of thousands of pictures.
The price is compatibility. HEVC is covered by patents, so many programs leave it out, and a picture that opens everywhere on an iPhone can fail in a web form.
Why browsers struggle
Safari opens HEIC itself. Chrome and Edge do not read the format, but they can borrow the computer's HEVC video decoder. Flex Convert reads the HEIC container and hands the picture to that decoder, so it works wherever the decoder exists.
Where there is no decoder, which is typical for Firefox and some Linux setups, the page says so and writes nothing. We tested Chrome on a Mac and Playwright's WebKit build, which is not Safari.
What survives conversion
Orientation is applied to the pixels and colour is converted to sRGB. Location, camera make and model and the capture date are not written: the test photos carried all five tags and the JPGs carried none.
Choosing
When to pick it, and when not to.
A format is a trade. These are the trades this one makes.
Keep HEIC when
you edit in Photos, Lightroom or another Apple app. You keep the smaller file and lose nothing.
Convert to JPG when
the picture is going to a website, a printer or a Windows PC. It is the one format every one of them accepts.
Convert to AVIF or WebP when
the picture goes on a web page you control and size matters. Both are smaller than JPG, and current browsers show them.