AVIF and JPEG XL are the two serious successors to JPEG. Both are dramatically more efficient. Only one of them is currently safe to put on a public website, and most guides on this subject will not tell you which.

macOS 15 or later is required to write either — that is a system codec requirement, not an application limitation.

What the two formats are

AVIF is an image format built on the AV1 video codec. It compresses far harder than JPEG at comparable quality — commonly around half the file size — and supports transparency, wide colour gamut and HDR.

JPEG XL is a from-scratch design intended as a full JPEG replacement. It compresses comparably to AVIF, is faster to encode and decode, handles very large images gracefully, and has a genuinely clever property: it can losslessly recompress an existing JPEG, shrinking it around 20% with no further generation loss, reversibly. For archives full of legacy JPEGs, that is a real and unusual capability.

On the merits, JPEG XL is the better-designed format. That is not the same as the more useful one.

The browser reality — the part that decides it

Checked July 2026. This is the fastest-moving fact on this page; verify it at caniuse.com before you act on it, because both entries below are expected to change during 2026.

AVIF is ready. Supported by Chrome since version 85, Firefox since 93, Safari since 16.4 and current Edge — roughly 94% of global browser usage. Safe to publish today, with a JPEG fallback for the remainder.

JPEG XL is not ready for the public web. Safari has supported it since version 17. Chrome shipped a decoder in version 145 (February 2026) but it is off by default behind a flag, so for practically every Chrome visitor a JPEG XL image simply does not display. Firefox has it in Nightly only. Chrome is expected to enable it by default later in 2026; until that happens, publishing JPEG XL to a general audience means most people see nothing.

That single distinction should drive your choice, and it is the reason a page like this exists: the format that is technically better is currently the one you cannot use in public.

Which to use, and when

Publishing to the web → AVIF, with a JPEG fallback. This is the mainstream recommendation and has been for a while.

Archiving → JPEG XL is genuinely attractive, particularly for a large body of existing JPEGs, because of lossless recompression. But weigh it carefully: an archive format’s most important property is that something can still read it in twenty years, and a format that most current software cannot open is a bet on adoption rather than a safe harbour. TIFF or the original files remain the conservative choice.

Inside the Apple ecosystem → either works. Safari, Preview and Photos handle both on macOS 15+, so for images that stay on your own machines the compatibility problem largely evaporates.

Sending to a client → neither, unless they have specifically asked. Send JPEG. A deliverable that will not open is a support conversation, not a feature.

Converting a batch

In Archyv, conversion runs from a template that holds the whole recipe — format, size, quality, colour space, metadata handling and output naming — so a repeat export is one choice rather than a rebuild. AVIF and JPEG XL sit alongside JPEG, PNG, TIFF and HEIC as output formats in Image Conversion.

The settings worth thinking about:

Quality. AVIF and JPEG XL both take a 0–100% setting, like JPEG. They hold up far better at lower numbers than JPEG does — but the same discipline applies: high for images that matter, lower only for thumbnails.
Colour space. sRGB for the web. Display P3 if the point of the exercise is wide-gamut display on Apple hardware, which is one of the better reasons to use these formats at all.
Sizing. Longest Edge constrains the long side and keeps the aspect ratio; Fit Within Box keeps both sides inside limits.
Metadata. The same six options as any other conversion, including Strip GPS Only — worth setting deliberately for anything being published.

Your originals are untouched throughout: conversion writes new files into a destination folder you choose.

Two cautions

Software support lags browser support. A format your browser renders may still be unreadable to a client’s older Photoshop, a print bureau’s workflow, or a stock library’s ingest. Browser compatibility is the easiest thing to check and not the only thing that matters.

Do not convert your only copy. Both formats are lossy at normal settings, so converting a JPEG to AVIF is a second generation of compression. Keep the originals — and if the goal is an archive rather than delivery, look hard at whether lossless is what you actually want.

Next: Image Conversion covers every option, and Conversion Templates covers saving a recipe. For the everyday web export, batch-converting RAW to web-ready JPEG and HEIC to JPG cover the formats you can publish anywhere today.