The Photo Format Your Phone Never Sends

Your phone almost certainly stores photographs in a format no browser will display. That's an odd situation for 2026, and the explanation has very little to do with which encoder makes smaller files. Image formats succeed or fail on licensing, and the last thirty years of their history is mostly about that.

JPEG endured by arriving first

ISO/IEC 10918-1 was published in 1992. It defines discrete cosine transform coding on 8x8 blocks, which is why heavy compression shows those blocks as visible artefacts. What you're seeing is the coding structure itself.

JPEG has been beaten technically many times over. It survives because a baseline decoder exists in every operating system, every browser, every camera, every printer driver and every piece of software written since the mid-1990s. Nothing since has matched that, and when a file has to open on unknown equipment, universality matters more than efficiency.

PNG exists because of a patent

GIF used LZW compression. Unisys held a patent on LZW and began pressing software authors for licence fees in the mid-1990s, which turned GIF encoding into a legal question instead of a technical one.

The response was PNG, designed in public on a mailing list and finished quickly, using the unencumbered DEFLATE algorithm. It became a W3C Recommendation in 1996 and an ISO standard in 2004. It's lossless and carries an 8-bit alpha channel, and being royalty-free was the whole point of the specification, not a side benefit. PNG is what you get when a community builds a format in reaction to a licensing problem. Keep that in mind as you read the next two sections.

HEIC won the camera and lost the browser

HEIF was standardised in 2015 as ISO/IEC 23008-12. Apple adopted the HEVC-coded variant, HEIC, as the default camera format in iOS 11 in 2017, and the compression really is good: roughly half the size of a comparable JPEG, with support for depth maps, image sequences and 10-bit colour.

No browser will decode it.

The usual explanation is HEVC's patent position. The video codec underneath is covered by claims administered through several separate licensing pools with overlapping membership, and shipping a decoder to hundreds of millions of users means dealing with all of them. That calculation was easy for a hardware manufacturer selling devices, and unattractive for anyone giving a browser away.

You've probably already met the result: photographs leaving the Apple ecosystem get converted to JPEG or WebP on the way out. The compression is excellent, but the open web never accepted the container.

WebP and AVIF learned the lesson

Google announced WebP in 2010, deriving its lossy mode from VP8 keyframe coding, with lossless and alpha support following in 2011. Adoption was slow for years and then suddenly complete: Safari added it in version 14 in 2020, and from then on WebP was a format you could simply use. That, and not the compression ratio, is why it's the sensible default for a photograph on a web page.

AVIF, from the Alliance for Open Media, is built on AV1 intra-frame coding and was specified in 2019. It compresses better than WebP, especially at low bitrates, and it was explicitly designed to be royalty-free from the start. Chrome shipped decode in 2020, Firefox in 2021, Safari in 2022. So it reached the web in roughly three years, about as long as HEIC has spent not reaching it.

JPEG XL is the interesting failure. It's technically strong, offers lossless recompression of existing JPEG files, and is royalty-free. Safari shipped it in 2023. Chrome removed its experimental support the same year, citing insufficient ecosystem interest, and without agreement between the major engines a format can't be deployed on a public page. Being good and being free isn't enough when you arrive after the incumbent is entrenched.

Choosing, in practice

Photograph headed for a web page: WebP, or AVIF where you can produce it. Anything that must open on unknown or older software: JPEG. Screenshots, diagrams, logos, anything built from flat colour and hard edges, or anything needing lossless transparency: PNG. Camera original you want to keep: leave it exactly as it is, in whatever the camera wrote.

Our image converter offers WebP, JPEG, PNG and BMP, and only lists AVIF when your browser reports an encoder that actually works. Most don't, which is why the option usually isn't there. It can't read HEIC either, because the browser it runs in can't. For those files, use the export options in your phone's photo app or a dedicated desktop encoder.

For most images on most pages, though, shipping fewer pixels matters more than switching container. A 4000-pixel-wide photograph displayed in an 800-pixel column wastes far more bytes than any format choice can recover, and Resize Image fixes that in one step.